Tube Radio Restoration, Hammarlund HQ-120

hi there i recently went to go visit a very good friend of mine and fellow radio enthusiast dan schultz now dan has got a lot of really nice radios kicking around and uh when i was at his place i was on my way out and spotted this hq 120 off to the side and was like wow that's a really cool looking receiver so i i looked over and and i said dan you want to part with that and he says uh you know after a bit of talking to him for a while he said sure so i promised him i would do a restoration video on this and that's what i'm doing right now so i hope all you people that are watching this enjoy this and enjoy following along so i'm gonna do a complete electrical resto on this you know basically take out all the caps that need to be replaced that you know stands for really the electrolytics and all the paper caps if there are any of that in this i haven't even looked in this what you're seeing right now is what i've seen i basically brought this thing home and it's sitting right here and this is all i know so what you're seeing is what i know and we'll go through this piece by piece together and we'll discover everything that needs to be done and go through a complete electrical restoration and make this thing come back to his former glory from say 1938 or 1939 now this is a really good example of a hammerline radio this hq 120 is the face is you know almost no marring or no scratching on it at all all the knobs are original the meters have an orange or yellow and the dials look really nice even the case is in very good condition could use a bit of cleaning up but you know that's pretty much where it's at for this so this is a general coverage short wave receiver for those of you that may have stumbled across this video or don't know what a shortwave radio is and what this thing does kind of in a nutshell is it receives a whole bunch of different frequencies it's like a broadband receiver it allows you to look at uh all an entire spectrum of frequencies you can go you know right from about the the bottom end of the broadcast band right up to about 31 megahertz which is pretty high so that's uh you know looking at the broadcast band if you're if you're to look at say your am and fm radio okay you have the am radio down here which is 550 kilohertz to say 1600 and then way up here you've got 88 megahertz to 108 megahertz and this whole area here you're not seeing so what happens is is this receiver basically goes to about here all right to about 31 megahertz and then there's just a little gap that you're not getting in here and then there's the fm broadcast band again so it really looks at just a large spectrum of frequencies and now these short waves so called what they do is they work on the principle like if you're to say go down to your local lake and pick up a rock and skip it on the water it kind of skips and bounces on the water well it's the same thing with radio signals what radio signals do is say japan is transmitting a radio signal it's going up into the atmosphere it's hitting the upper atmosphere there are actual layers and i won't get into all that but we'll just call it the upper atmosphere it's going up there and it's bouncing and coming back down over here in north america and what we can do is we can hear signals from japan we can hear signals from australia lots of signals from asia some from russia they're all over the world you can listen to and there is no internet connection there is no cable connection there's really no anything all there is is an antenna wire that comes off the back of the set and it's usually called just a random length antenna you can cut them to resonance which means that you're tuning them for a certain area of the band and then it'll really hear good in that one particular part or you can just run a random wire out which is usually about i i like to say about a hundred feet or so so you run a piece of coax off the back or whatever and then in the outside your host you just run a 100 foot piece of wire and you listen to signals from all over the world on just this box here without any connections to anything else and that's really what a shortwave uh receiver does in general coverage receiver now there's kind of a sport behind this a lot of people like to collect receivers like myself and you know compare them and listen to them and all that kind of stuff and you can listen to ham broadcasts and all sorts of things on these things too so they you know they come in handy for myself and you know so that's really what this is in a nutshell so what we're going to do is go through this thing and as i say just step by step go through it and completely restore it and bring it back to his former glory so let's get into it and i'll pop the lid next and we'll take a look inside and see what they've done if see if there's any tubes inside of it or what they've done to this receiver and we'll go through step by step and bring this thing back to itself again here we are looking at the lid of the hammerlin radio so how you get into this radio is you just stick your finger in here and kind of pop this open hold put my hand yours doesn't go flying and like so and then you can see there's a little clip here which just clips to the front of the radio here and we're inside much easier to get into than some of the solid state stuff huh so here we have all the tubes laid out inside this thing and we immediately notice that there's two tubes missing one here and one here so this 6z7 here has got a phenolic tube socket and the 6k8 which sits over here which is the mixer tube has a porcelain tube socket you're probably wondering what's the difference in the tube sockets well the reason that they have a porcelain socket on this side is because you need an actual tube socket that's really sturdy that where the contraction and expansion of this tube socket is uh kind of held under control whereas if you have a phenolic socket on this side here they move around with heat like crazy and what happens is that you know sometimes just you wouldn't even think of this but the actual wiring that's connected to those tube socket pins and the actual tube pins are moving around a little bit with with expansion and contraction when the tube is heating up and cooling down now that expansion and contraction changes the capacitance between the pins of the tube it changes the capacitance in the wiring in the chassis and everything so by when the capacitance changes that also causes dial drift so what they've done is they've got a porcelain tube socket over here and of course it's more controlled it's a little bit more rigid than a phenolic tube socket so by having a porcelain tube socket they're controlling the drift that way by having a more sturdy structure holding that vacuum tube so that's the reason that there's a porcelain socket there and a phenolic socket on this side because you don't really need to have porcelain sockets everywhere so they're just looking at drift it's the same thing the main tuning condensers are under here and they all have a porcelain structure on them and uh that of course is uh you know part of drift compensation stopping the uh the radio from actually drifting too bad you got to keep in mind when you when you have this radio off for a day it's at room temperature right it's nice and cool but you know with this lid closed like this just using you know the vents on the radio itself you have all of these tubes that are just blazing hot in here glowing inside this unit making this go from room temperature to you know as hot as the blazes of hades so by having this you know small vents on the back allows a little bit of ventilation in here but you also have a very very vast temperature range where it's going from room temperature to its actual operating temperature and that of course incurs drift so all these old radios you always see a little bit of drift so they always tell you you know warm the radio up for a while before you use it and that's just standard practice with any vacuum tube receiver they you know as i say there's a very very large uh temperature variation you'll notice that in in the more modern receivers that use transistors or ics there's not very much drift in them and that's because there isn't such a large temperature variation has nothing to do with the actual structure of the transistor itself or anything like that it's just the fact that it's not really going from room temperature to as hot as your your kitchen oven so you know this is a reason that we're that people say oh tube radios drift well no actually if you let them warm up and stabilize they're actually very very stable and the designers of this hammerland radio took all of that into consideration when they were putting this thing together so this is the mixer tube here and you can see there's a rubber wire on the actual uh grid cap and the the rubber wire here is just as crispy as pie crust so we're going to go inside this thing and replace that wiring you can see somebody is very hopefully you know this is a real hack job mounted a speaker on the back doesn't look like they've done too much damage it's just you know they've mounted it to the back here and they're firing it you know out this way which is kind of useless because i'm listening on this side of the radio so we'll get rid of this and use a proper communications speaker in that spot a bunch of really interesting things that you know are kind of overlooked in the design of these radios and one of them is they use a 5v4 as a rectifier tube in here okay and we can see the plate structure here and we can see the little coily white filaments there and then the the actual indirectly heated cathode well what's interesting about this tube is that coily filament is directly connected to that cathode so in effect a heater to cathode short really if you think about it because it's part of the cathode surface now you're probably thinking to yourself why the heck would they design a tube like that when they can just use a 5u4 and it's or 5r4 and the filament itself is actually the cathode they've actually tied the filament itself to an isolated indirectly heated cathode kind of makes no sense right well there's a reason for that and it's called controlled warm-up time so what happens is when you first turn these radios on this transformer has no load on it so the b plus the ac side or the plate side of this tube goes really high in voltage okay because there's no load on it so when this is going really high if you have say a 5r4 in here which is a directly heated tube instead of this right what happens is you turn the switch on on the radio now it's doing its rectification and that tube is full in it's it's putting out all the voltage that this thing can you know supply and none of the other tubes in this receiver have warmed up at this point so the voltage surge is really high and then when all the rest of the tubes warm up it drags it down slowly to below really the safe ratings of the capacitors so by having a controlled warm-up time this tube warms up as well as its fellow tubes inside of here and you don't get that really high surge voltage that's kind of destructive to the filter capacitors and such so it just makes it a little bit more reliable and that's why they've done that that's why they've designed the tubes like this so this has got a 5v4 in here just to control the warm-up time so that we don't get such a high surge voltage you see the 6v6 is an audio output tube right here and if you look at the plate structure inside of this i've never really quite seen a plate structure inside a 6v6 so big like look at that that's a really large plate structure in there i've got lots of 6v6s and none that look like that so um yes this would probably love to find its way into some guy's guitar amplifier i'm sure very interesting looking 6v6 made by raytheon so there's that here we have another tube here which looks like it has a shielded lead running up to the grid the grid cap this has got two triodes inside of it we can see right through the st style glass here so this is a 6f8 and what the 6f8 looks to be doing on the schematic here we look at the 6f8 here it looks like it's doing detection and amplification here so we have a 6z7 that's the tube that's missing and that looks like that's the noise limiter tube you can see the limiter and this is on and off and it connects and disconnects the cathodes of this tube so this can't really be doing any detection at that point so the detection is is obviously occurring in the 6f8 and then of course the amplification is is uh occurring here so if we follow the grid line out you see it goes to the audio gain control and then it runs you know into the plate of this tube here and then we can also see on this particular side here we have the grid and the plate tied together which usually indicates that they're just using it as a diode right and that's acting as the detector on the other side so that runs off to this line which of course runs up to the last if transformer which makes sense we have down here the bfo circuit the bfo circuit is the beat frequency oscillator so this is what you use to insert that that small carrier to create a heterodyne tone in that tone uh allows you to listen to cw so if you don't have um a bfo in your radio and you tune in to cw on the shortwave band it'll sound like static turning on off and on it'll kind of go if you're listening to you know cq and morse code whereas if you have this and you turn this on it'll add a tone so it'll go you know you know it'll actually put the tone in there whereas your before you would be listening to the actual static this is the output tube here that we just looked at the six sf5 which is over here and kind of hiding is looks like some sort of a meter control circuit it's running right up to the meter amplifier some form of a control circuit and we can see over here this is the input rf which is a 6s7 it goes from there into the 6k8 mixer and then through the if chain and out the last if amplifier which is the 6f6 which is another really interesting choice for an iaf amplifier so what happens is the chain really the antenna basically it comes into here it goes this way around and then comes back out over here and then it goes from this transformer over into the detection over here and then runs out the audio output tube this guy is a voltage regulator tube and they normally glow purple so if you see one of these tubes in there it's a vr 150 and it's glowing purple it's not bad it's not gassy it's uh it's actually supposed to this tube has a gas inside of it and it's designed to regulate voltage at 150 volts hence vr 150 voltage regulator 150 and that's nicely stamped into the socket here also vr 150 down there when you're pulling these out you got to be careful just kind of rock them and gently pull them out if you bend them too much you'll break the indexing off in here and you don't want to do that and then you'll have a real hard time trying to align it to the right pins so what i do is like i this one is just fitting in perfectly here but if you don't what i normally do is i put one finger on the top and you just rotate it like so and it just falls in so those are pretty easy to put back in these octal tubes they also have a a tube and a lot of other radios filcos are really known for them is they're called lock tool tubes and they actually have a lock on them a little lock on the base with small pins and those tubes also have this kind of an index in the center but they also have a little clip on the bottom which holds them in and they were widely used in automotive radios because they're a pretty sturdy tube to have but these are locked holes or octal sorry not lock tools so that's pretty much how this thing works inside here you know there's a nice potted transformer down here here the dial lights right here in here and there's a dial light in the meter a lot of people were crazy and they pushed this thing right up to the meter and burnt you know the front part of the meter so this one is looking like it's pretty good still i always use like to use a small shallow kind of a rounded head bulb a lot of them use the long kind of uh like 47 style ball i like to use a little rounded head guys so that just in case you actually do bump it or something it won't burn the face of the meter and sometimes i even get really crazy and i will led light these things uh just the actual meter itself so that there is no chance of that happening there's you know massive space between this bulb and the actual dial here so you're not gonna ever burn that but this is a kind of a sensitive little area here so depending on it this one here i'll probably just put a dial light back in and light the meter up that way here we are on the underside of this hammerlin hq 120. this was much easier to get into than i figured i didn't have to remove all the screws on the face or anything all i had to do was tip it up and remove the screws on the bottom panel and we're inside a lot of these older radios you gotta remove the screws around the face and pull them out of the cabinet and i just took that for granted probably have to do that with this too so i'm kind of thankful it turned out like this is pretty easy to service and somebody has taken advantage of that easy to service and i'll show you here right shortly what i'm talking about we can see on the underside here that all of these pink capacitors have been changed at one time they're tiny chief capacitors and they were replacing these waxies somebody removed most of these things and put all these pink ones in well that does this no good today because all of these pink ones are bad also they're paper caps and they leak like crazy so they're no better than the waxies so the waxies have got to come out and all the pink caps that you see in here they all gotta get removed this guy is kind of floating in mid-air as a filter cap so that's got to come out and there's two down here that are probably going to be bad also and well i know these are bad and i'll show you that too here in just a second we can see that they've botched this section up here quite a bit you know there's resistors just floating in midair and wires attached to them here there and everywhere is another floating thing down in here where the wires have just kind of all come up to a one point they've kind of you know attached them all and just they're hanging in mid air like that and salted them together so that all really has to go so i don't know what they've done in this section here it looks like they've tried to modify it there's a six it's marked 6h6 here but there is no 6h6 within this chassis there's a cover on the bottom of the bfo here that's missing so i'll have to make something up here and basically that's just to stop the injection level from being too high and they put a can on it to shield it to uh you know keep the bfo injection you know not crazy so i'll have to make something up for that we can see as i say a lot of different resistors a lot of resistors have been replaced here's one here one here these this is not factory uh you know they're all over the place i can but just by looking at this choke down here i can see that some of the hit the hair like wires on it are you know kind of coming off so i don't know if this choke is open or not i'll have to check that and um yeah it's so you know this is really kind of an extensive repair this will take me a little bit but i'll go through step by step and we'll get this thing working again at this point here i might just as i say change all the caps and well i will change every cap aside from the micas and i may even re resistor this entire radio i might have to wire a whole lot of it too it's looking like it's looking like it might need it you see some caps or something here has blown up at one time we can see this dark spot over here and uh it looks like something has you know exploded pretty good in that corner batteries in my flashlight are kind of going anywhere you see it's so you know it's it's got a lot of issues or some other blue looking cap up in the corner here it's kind of yeah probably going to be bad also whether it is or whether it isn't it's out of there so now when i tell you that somebody took advantage of this bottom panel here the bottom panel let's grab it fits you know on the bottom like so and then you got to remove all the screws all the way around right somebody's even wrote bottom front they've been in here so much that i guess they want to you know mark it so they get the panel on the right way if we look at the trimmer caps here on the coils see these trimmer caps that they're almost all different this one's different from these three and then these two are different again and then we look down here and there's one that's been replaced down here also now usually when you see this inside a radio like this what this means is that somebody's done a lot of screwdrivering because they can't keep this thing stable and they can't keep it on frequency maybe the dial is drifting a lot so what they've done is they've screwdrivered it so much that they've wrecked the trimmer caps and they've replaced a bunch of them in here and the reason that this happens is because these old waxes that are originally in here and now even these red guys too they would act just like the waxies what happens is over time they decay inside and they start to leak electrically now when i say that they're leaking i'm not talking like a physical substance they're not leaking oil or goo or electrolyte or anything like that they electrically leak so what happens with these caps is they're only supposed to pass ac alternating current and what happens is they start to leak and they start to pass dc through them and when they pass dc they're effectively turning into resistors and when they do that they drag other stages down in the radio and cause resistors to get hot they'll burn out if transformers they do all sorts of things when when these things go haywire so what was probably happening at the point why these got screwdrivered so much is that somebody didn't replace any waxies in here at one time or they did and these guys are starting to go bad and it kept drifting off frequency or the oscillators kept moving so what they did is they probably kept screwdriving and screwdrivering it without trying to figure out the problem and then wrecked all the trimmer caps and that's a common thing within these old radios when you know people get in here and they don't know what they're doing so what's going to happen is i'll you know check the values of these and make sure they're you know somewhat close if not i will replace these trimmers also and these are usually really good these are got usually some sort of a mica in here between them this one here is almost wide open look at that so they usually have some form of mica in there and you know a compression style trimmer capacitor right so we'll go in and i'll probably leave some in and replace the the ones that need it these look like they're you know really badly tarnished you know like it's looking looking not very nice there so we'll have to get in there and see what's going on with those guys too so what i'll do is i'll remove the camera off the tripod here when i come back and we'll test some of these caps and i'll give you an idea of um what confuses a lot of uh maybe newbie techs and just or guys that really don't work on tube equipment so when i come back we'll look into that okay so here's a closer shot of some of the electrolytics now if you look under here right in this far back corner right here you can see this cap here has actually kind of exploded and sprayed some of its internal goop on this wire here it can pick it off with my finger you see that came right off there and you know these are all pretty much ready to do that this guy here is as i say floating in midair and uh take a closer look at those ugly trimmers in there you can see how ugly those guys are those are the waxies there and these are all the tiny chiefs that have got to go there's even ones hiding way down in here so i've got to get down in there and clean them all up and maybe i can get closer to this wiring rat's nest here and give you an idea see here how these are just floating in mid-air and there's another one that's just floating in midair here look at that ugliness yikes see it says 6h6 on the chassis here there's no 6h6 in this radio so somebody's tried to modify this there's that hideously long stripped piece of wire here runs right up to the switch and um you know black tape down in here look at this you know it's um it's got a little bit of work to be done here i look down in here maybe i can get a shot of that snapped off screw right down in there you can see it right down on the bottom there so there's quite a bit of uh mumbo jumbo in this thing that needs to be cleaned up all these resistors and caps that are hanging out inside here have all got to go you see all these guys lined up here and down in here same thing so so that's what's going on right now so i've got my capacitor tester on over here and what i'm going to do is open up the leads on this guy right here and so i'll leave this attached to the the frame here i'll connect the negative of my capacitor tester here and this end will be open let's have it the cap hanging out kind of like this one here is just kind of hanging off and we'll test this cap and we'll look at it for leakage on this capacitance tester here and see what's going on so i'll do that right when i come back here okay let's open up this tiny chief capacitor here from its circuit and test it what we'll do is we'll desolder it from the socket so that no resistors or anything else loads the circuit so basically this is just open right now and we can see it's tied to the chassis that's fine because we'll just the chassis is isolated from everything we'll just use this as the negative side for the leakage tester and i'll tie one side of the gen rad to here okay we can see that it's rated at .05 micro farad it's a 400 volt rated cap okay and i'll put that on here and here and we'll scoot over to the gen rad all right so i'll hit test here okay so we're 74.620 nanofarad so what that means in microfarad is that's 0.07462 so if we test this on another tester like my dlm 240 which i'll show you in a minute it should read 0.075 is what it should read on a normal like a smaller capacitance tester so we'll come back here and we'll do that right now i'll remove this here i'll turn my dlm 240 on this negative to here and we'll clip this to here and there you go .075 microfarad so that's kind of normal for these old caps they're around that area they move around and of course we do know that these old caps leak a little bit too inside and the fact that they're leaking means that it takes a little bit more time for the circuit to charge the actual capacitor and measure the time so it's going to look a little bit higher all right so that's 0.075 mics and this is a 0.05 now most people would think that that's okay all right because it's reading capacitance and all so now what i'm going to do is i'm going to hook up my leakage tester the same way and we'll focus on the leakage tester okay this is a very important test for vacuum tubes and this puts a lot of voltage across these caps so if you're ever using a leakage tester you got to be ver very very careful you don't ever want to touch this while you're testing because it'll be 500 volts in some cases on this one lead so if you ever do use these you got to be very careful make sure your leads are shielded and of course you're doing this all at your own risk so that's the way it goes with old vacuum tube stuff there's a lot of voltage inside so this is a leakage tester and what it does is it applies voltage across the capacitor here okay so we'll start out at six volts and we'll test it at six if that eye opens it's not leaking at six volts so it's not leaking at six volts let's go to twenty see how it's not fully opening it's already starting to leak pretty bad at 20 volts now that capacitor is rated to be fine up to 400 volts and of course at 100 that i won't even open as we can see already we know that so that's leaking completely leaking that's a resistor starting at 20 volts or around there even earlier and at 100 volts it's definitely a resistor so we know that this tiny chief has definitely got some issues and they all need to go like all of these capacitors need to you know be removed out of here now if we do the same test across you know a newer style capacitor this one here is four seven three all right let's see if we can get a focus on that there so that's 0.047 let me put my finger here maybe it'll focus on my finger just too close there we go 473 okay at 630 volts right this is a newer polypropylene capacitor so what we'll do is we'll test it on the gen rad so i'll focus back up on the gen red here and i can't see in the screen here so you can see this here hooking it up and we'll hit test and that's 0.0467 so you can say that's pretty much right on .047 microfarad and we'll test it on the dlm-240 just hook it up to the dlm-240 right now and you can see here that it's 0.047 right on the nose that's a newer cap so we'll go back over here and look at it on the leakage tester all right in fact how about let's do this to make the test really good let's solder it to the chassis i know somebody put a little solder blob here on the corner of the chassis so we'll just solder it to the chassis and test it the same way we were testing the other caps this has a bit of solder on it okay so now this is basically testing this exactly the same way that we're testing the other caps and as you can see it'll still read the same this way it's just doing this just to make the test exactly the same 3.047 right there okay now we'll do the leakage test i'll tie this to the chassis again and put this to here okay all right so we'll go down to six volts see it's absolutely fine go up to 100 absolutely fine the reason you see the eye opening slowly is because it's charging the capacitor and then when i let go of this switch it discharges the capacitor some of the other capacitor testers don't do this and you've got to be very careful with those testers that heathcote it11 isn't spring-loaded they may have corrected that in the in the in their future models that's a heat kit it11 right under there this guy up here and this switch as you can see it stays in the leakage so if you uh just you know disconnect the capacitor at that point it's fully charged it won't automatically discharge it they may have fixed that in the future i'm not sure but this one is not spring loaded so anyways back to our test here so we'll go right up to 500 volts so we'll put 500 across this cap it's rated for 630. we'll press the test look at that absolutely no problems that capacitor is very good and this is a very very sensitive capacitor tester so this is anything haywire with that cap that i will not open so we can see that these capacitors these new polys are really good capacitors now i'm also very fond of these disc type these guys here work very good for rf bypassing and i will probably use a whole bunch of these particular caps these are 0.02s and i have .01s and i'll use these in here for rf bypassing they work very well at uh at our frequencies and drag the r after ground really nicely so you'll notice that hammerland used a lot of these in their sp 600s and even in the hq 140 they had old disc caps and to this day they're still fine you don't have to recap those the only thing that needs to go is the electrolytics so these guys are all paper and they all need to go so let's look at here really quickly an old waxy before we do anything here and i'll tell you a couple things about waxy capacitors here also so these guys here are almost always faulty whenever you see these in any radio it's a hundred percent out these have got to go and to tell you the truth any tiny chief cap you see they've got to go to because these are our paper caps also so you'll see that they've got a line at one end here all right see that line now that line denotes outside foil that's all that that line means so what happens is this lead here runs to the outside foil the foil that's closest to the outer shell of the capacitor here so technically like this is all shielded right up to this point and then this one here would be the inside layer uh foil so this end of the capacitor always goes to the lower impedance point of the circuit so if you were to be using these for rf bypassing this end always goes towards ground you can see they've even helped you out on this one this is this is marked ground at this end here and you can see they don't mark ground on a lot of them because this really wax caps aren't polar electrolytic capacitors are polar 100 percent but these guys here that's the only reason that line there it just it's to help you uh get less hum and less interference in your circuit so this guy here will always tie to the chassis side if there are bypassing caps so what i'll do is i'll test this uh waxy here we've still got the negative lead of the leakage tester here tied to the chassis and this guy this end is tied to the chassis so what we'll do is we'll hook our leakage tester to this guy here now this is the same company of capacitor and basically this is you know what's inside here is what's inside here this guy's rated a little bit higher voltage you can see it's .05 at 500 volts it's made by cd just like all the other capacitors are and we'll we'll check this one out on the meter okay so here we go we'll start off at 6 volts again all right not too bad at six volts look at 20. same kind of idea it's opening a little bit but not fully so this one isn't leaking as bad at 20 volts but it is leaking and of course at 100 we're gonna you know pretty much see closed eye here so we can tell that that's really bad these this fella is leaking real bad so it's the same kind of idea as the other pink style capacitor the tiny chief and uh what we'll do is i'll just hook up the dlm-240 here again and we'll compare the the measurements of that cap okay so on the ground here and we'll go up to here and we can see it's almost exactly the same reading as the other capacitor well they're made by the same company and they're basically the same cap one's just in a molded shell and uh one is in a uh a waxy and a cardboard kind of shell so we can kind of tell the paper inside is breaking down between the foil it's probably going acidic and it's definitely leaking dc across we can tell it's taking a lot longer to charge this capacitor because the capacitance rating is up just like on the the pink guy so we know for sure that all of those capacitors are bad so all of the pink caps that you see within this chassis all hiding under here and that blue guy up there and all down through here and these electrolytics are bad too there was a very large electrolytic originally uh strapped to this point here and it was you know in the in here big cylinder and somebody's replaced them with more cd style caps these guys are electrolytic too all right this one here and there's two in here this one is actually leaking and has spewed some fluid out of one end of it so we know that it's definitely bad as seen earlier so that's kind of a quick rundown of some of the parts and pieces in this chassis i haven't really gone and tested any resistors the ones that are probably pretty close i'll end up leaving and i may change them all i'm still kind of undecided yet usually when i get in and start testing and you know depending on how badly wired this is it might just be easier just to completely start over again and uh go from there so this guy was just tacked up here like so you see that at the top there so somebody's obviously opened it and tested it at some particular time and um you know it's uh obviously in a pretty bad state of disrepair right now so so on to the next step i'll start removing some components here and i'll show you how to cleanly remove components and when you're starting to do a recap or re-resistor job and how to go in and do that just before we go removing the components out of the chassis here and you know continue with the restoration i'll give you a couple hints here i've drawn up a small schematic here if you're going to use capacitors that do have a banded and say you have some a polypropylene caps that you know have a band on one end the band end always goes to the lower impedance portion so the band of the capacitor will end up going towards the plate here and then the other side of the cap goes towards the grid and so on and so forth so the signal path is really coming this way and going through like this and out all right and again if you're going to be using capacitors with a banded end the band you always want to go to the chassis or to the lower impedance point of the actual circuit now a lot of capacitors nowadays like these new polypro caps don't have a band on them and in order to get the optimum performance out of this capacitor you kind of have to determine which end is the band if you figure that it's important in that circuit and in the next shot i'll show you how to determine which end is the band or the invisible band on these particular capacitors this is how we determine the outside foil end of one of the newer polypropylene style capacitors so this particular capacitor has no markings on it it's just an epoxy dipped polypro cap and we don't know which lead actually is shielding the capacitor which which lead attaches to the outside foil and we can very easily verify that by using this old oscilloscope or any kind of oscilloscope and the coupling from our bodies so we'll capacitively couple our bodies to this capacitor how's that for confusing and we'll use our bodies as a 60 cycle antenna in order to verify which end is the outside foil so the scope i'm using is just a little os 8 style oscilloscope and it's just got a directly coupled probe here this probe is you know this goes right into the center conductor right into the scope there's no capacitors in there through a piece of shielded coax into the bnc connector here on the vertical section all right and what we're going to do is we're going to turn up the vertical section to extremely high sensitivity okay so that's very high you can see this is just picking up this noise out of the air probably switching power supplies and the hum from my body see when i ground it out it goes away so you can see that it's just picking up random noise so what we're going to do is take one of these capacitors i'll grab this cap right here okay and we'll hook it up like this and look at the oscilloscope so we can see that we do have some hum there just for me holding this capacitor so i'm capacitively coupling a little bit of hum into this cap this way so we take note of this signal here all right and then we'll reverse the leads and we take note of the hum there now we notice that we have a lot less hum introduced into the oscilloscope that way through my body so that tells us that this end is the band end or the outside foil in because this end is now shielding me from becoming close to this lead right here because this is the outside foil it's connected to that one end so we know now that this end is the outside foil end and we could put a little dot on this end here of this capacitor and we would know for the future that and when we're going to put it in circuit which side we want to tie to the chassis or if we're going to put this into a guitar amplifier we would know that this end of the capacitor would go towards the plate and this would go towards the grid of the next stage okay so now if you have a whole bunch of these capacitors you could test a whole bunch of them and see if they're all the same way i don't know if they're going down the run the same way or some of them are backwards going down the run and they're just printing the the uh you know the the ratings on any old side here but you know if you tested 10 or 20 of these things and you determined that they're all the same way you could pretty be pretty confident that your whole batch is probably the same way and then just put a dot on all of them and if one was to go test a lot of capacitors you could actually even make a small test fixture that would do this automatically you just plunk this thing into the test fixture and have something that would introduce some some noise into the outer side here and you would know uh by you know popping all these into a test fixture which way the uh the outside foil is so we can see that this way here when i hold the capacitor like this it's less noise this way then when we reverse the leads and go like so we can see there's a lot of noise so we know that this is definitely the outside foil because this is coupling to my fingers capacitively and it's introducing that 60 cycle hum in the scope so i have another capacitor here and we'll hook it up the same way so the lettering starts at this end here okay in the numbering so i'll hook this one up the same way and we'll see if this one is noisy too nope see this one is quiet this way so this one is reversed you see that this one is reversed so if i reverse these leads you should see some noise see that so this one here you couldn't do that so these capacitors are going down the run any old way this way here or this way here they're they're coming down the run like this and getting stamped any old way so these ones here i couldn't verify by doing that i would have to you know put each one on the oscilloscope here and then just capacitively couple my fingers to it so you could have your scope sitting on your bench and just do this as you're going and it would be a very simple procedure for you so that's how you determine the outside foil end whenever you're desoldering any wires from these porcelain tube sockets let's zoom in here that have fingers on them that are like this here you can see how it's got kind of a tab here a tab here and then another little tab here and then the wire kind of runs up in into the middle of them and they've soldered them together don't bend these tabs if you if you can get away with it because all of these tube sockets that have these tabs if you bend them they just snap right off so what you want to do is just kind of very carefully heat it and then pull the lead out of the actual um tube socket connection here so you know put a bit of solder in if you need to add some solder to you know make a better thermal connection to get it out sometimes i find that helps a lot and then just pull the lead out with a pair of pliers and don't bend these little guys because they really do they break off so easy and then of course when you're dealing with a connection that's like this guy here what you really want to do is get your pliers in here and they've got kind of little ears on them you can kind of see here right they've run this wire kind of around here and tucked it through now some of these you can get away with because they haven't really wrapped it or kind of coiled it around the connection a lot of people do that and a lot of companies did that and it's one thing that i was really thankful for with the tektronix corporations they never did that because there really isn't a need to do that it just makes repair very difficult and what they would do is they just stick the component through and solder it and that's exactly what i do i never really curl them around unless it's a very high heat application to where that solder joint might you know you know in the future become a little bit soft and the component would fall out but you know in a normal situation where there's just a a small resistor that doesn't emit any heat and a capacitor attached to it there really is no reason to wrap them around these posts now i never remove capacitors mid way up like this guy has done here you see that he soldered this onto here like this and he's just kind of cut it and that's how that fits in there i don't do that i'll remove the actual wire right at the socket itself and it's usually pretty easy like there's a lot in here that you don't really have to trim any ears off of i get my desoldering tool in here okay and put it here kind of heat it up a bit you can see that it just pretty much cleans that right out and then you can just remove the wire now i don't really need to remove this wire because it is a transformer wire but i just use that for an example to show you now a lot of people do wire wrap around these particular terminals and then you have to clip the lead off or clip the little ear off but this one looks like there isn't a whole lot of that going on in here so this will be a little bit easier to get a lot of these components out because we won't have to worry about you know trimming the tube socket there's a bit of an art to that if you you know if you trim too close to the tube socket pin you cut an edge of it off but once you get to realize where the ear is if you just get your clippers in i'll grab a pair of my uh sharp clippers here if you get a pair of the clippers in it just the right spot okay so let's focus back down on that green resistor there you know if i was to get in here and i wanted to get rid of this i would come up to this like so and i would pinch it right at this point and it would cut that ear right off these are very sharp and it would cut it flush with that tab and then when you desolder it you've got a little bit of crud left on here you have to desolder that sometimes just by heating that up with your normal soldering iron and then flicking you know flicking the tip off somewhere just flick the tip of the iron off you'll clean these up pretty good if you want to make holes you know have the holes present again a vacuum desoldering tool like this uh you know haco 470 with this 802 head on it is a a very handy tool to have right so of course um by having it that close it's hard to read so there you go like this old haco 802 works very very well now this heco is modified the the the haco 470 itself is a very slow pump in it and they do they do work very well it has an induction motor in it and i noticed that the haco 470 is a much more reliable unit because it doesn't have a brushed motor it's an induction motor so i designed a drive for mine and you can hear how fast mine goes uh it goes you know half to you know a third of that speed you know what without the drive hooked up to it so basically i'm just changing the frequency that's going into that induction motor but they have the heco 470 and the 472 has a dc motor in it and it goes very fast uh the 470 has got great suction even at a low speed but by speeding the 470 up you really do get uh pretty incredible suction there and it basically never plugs but uh yeah this is a great handy tool to have whenever you're working on old radio chassis or guitar amplifiers or anything like that that the tip heats up it's part of the soldering surface you can even solder with this if you wanted to have your solder in this hand and go in and solder with it because it works just as well that way also so it's a great tool to have kicking around and if you have one of those blue vacuum pumps i think i've got one of them in here do i no i don't i've moved them uh i have uh the blue vacuum pump where you press the end in and then it's got a little button you press the button and it it sucks the solder up those work very very well too and they're very effective in working in these particular kinds of circuits you don't really have to worry about damaging anything with those if you're working on printed circuit boards and you've got the big the big you know solder removing one sometimes the kickback can can take the traces off the board if you're not careful but in most cases if you're careful you can get away with using one of those pumps too so what i'm going to do next now is i'm going to get rid of all these caps i'm going to take all these caps out and probably put in a lot of new resistors and get rid of everything in here and clean things up quite a bit and i'm just going to move my way probably around the chassis i'll come down here and then maybe move over to this side and then this side here is going to take a while because people have really botched this up like you saw in the last couple of shots there so i'm going to probably have to almost strip this entire section out and completely rewire it start over again and get that going and then i'll have to find some sort of a can that will fit on the bottom here it looks like a small tomato paste can would probably work it's uh this is just a shielding can it really doesn't do anything it just keeps the injection level down so that you know you don't get too much bfo injection by having this leak the signal out of here so that's what i'm going to do next i'll put some new electrolytics in here like you see down here that one that was floating put some new electrolytics in and fasten them up and once i get to that point i'll come back and i'll show you what i've done and explain that here i am starting the re-resistoring and recapping of this receiver and you can see that there's a mixture of the poly pro caps here and you can see there i've marked all the ends my oscilloscope's going on the floor there and uh you can also see that i'm using disc type capacitors and i've replaced most of the resistors in this area here i'm still working on these you can see these are all open and kind of hanging out here and down into here i've replaced a lot of capacitors and i'm kind of moving my way down and into this area here so really on this side i've just got to get rid of these this guy here these and go down here and get rid of all this and clean it all out i've kind of worked down here i've replaced the resistors down here so that i get rid of a couple of waxes and so on so there's a reason that i'm using two different kinds of capacitors here and i explained that earlier a little bit these particular caps are really good for rf bypassing and i like using them in areas that i can to you know to do efficient rf bypassing now there's a difference in these particular caps and these caps yeah they both have the same rating and they're you know roughly rated around the same voltage but these particular capacitors will move in value with heat and you want to be careful about using disks around the actual converter area and that's the reason that i'm using all poly pros you can see they even have a mic on one of them and by using these you might actually add a little bit of instability so you want to be very very careful with that so the poly pros are a little bit more temperature stable than the these uh disc type capacitors here i'm also replacing all the resistors that i can with a metal film and carbon film resistors just for added stability you can see these are all here this looks like there's a cap missing on here according to the schematic i don't know if it's on the other side here i'll have to check that i'll probably go in there and replace that capacitor this is a very sensitive area i might replace that with an npo style capacitor so that it's uh you know as the temperature changes it maintains its value we'll see how it goes as i go along you see i still need to get rid of all these tiny chiefs in here all of this is gonna go on this fella up in here i've replaced some wiring in here you can see the wiring that runs under here this was uh it looked like it was actually shorting at this point here i don't know if you can see that dark mark there looks like it was shorting on there so that might have been one of the reasons that this other fellow was in here so much i don't know it was kind of a hiding short so i replaced that wire down into here i have some old cloth wire it's actually newer cloth wire and it's got a plastic center in it and it looks really good so whenever i get a chance to use it i use it in these old receivers you can see the fellow before me has just used regular yellow wire i might even get in there and get rid of that so just going through and trying to choose the best components for the best area there's a couple of areas that should be rf bypassed in this receiver that aren't and they might have done that to cut costs because back in the day when they put these particular receivers together uh these components just regular components capacitors and resistors were pretty pricey so nowadays this stuff is really cheap and i've got a lot of the stuff so what i'm going to do is uh you know make the appropriate rf bypassing and such in this receiver to make it to improve it just a little bit when i'm done i'll include all this stuff on a schematic and i might even post a schematic or if anybody wants an improved schematic or you know if they're happy with the way that this receiver works i might you know have a schematic available i'll see how it goes in the end here so right now i'm just uh at this point here i still as i said you got to do all this gotta do all this get down and get some waxies in here and then i get over to the ugly side i get over to this man that's gonna be brutal can't see here because i got too much stuff in the way that's gonna be brutal but uh i'll get in there and clean that all up too and um i noticed that there's another schematic uh on this particular receiver that uses two six h6s and they lose one gain stage in the audio i'm not too keen on that i don't know if that was cost cutting or what they were trying to do there but uh there are two uh schematic variants for this one and i like the one in this receiver much better so i'm going to maintain this schematic and you know still use that triode as the detector and and i don't want to eliminate one of the gain stages they remove one triode in this to add another 6h6 if you look at the schematic of the of the variant of this particular receiver you'll see that so that's where i'm at this point when i've got more to show i'll be back as you can see i've got two hammerlins open on the bench now this is a 129x and this is the 120 i'm working on no i'm not going gung-ho and doing two at once and uh there's a reason i have this other one open and the transformers or the filter chokes i should say laying around are the uh a pretty good hint to that so just before i get into that i'll show you the side here i've recapped and re-resisted these sides you can see how i've mounted the disc style capacitors in there and all the new resistors i haven't cleaned this up wire wise or cleaned out all the little trimmings and stuff on the bottom here yet so because i'm still working on it so i've worked my way over to this side and i've tested this filter choke here and it's good and this one here is supposedly the same filter choke so this is the bad one which is right here which is uh number 20 on the schematic is the bad one and a lot of people complain about number 20 going open and of course mine is open so i've been doing a lot of reading on forums and everybody says that oh the chokes in the 129 are the same as in the 120 and you know either you can just move them around and they'll work just fine so i've taken some resistance readings now the dc resistance of this choke right here is 270 ohms same size same physical size and the dc resistance of that choke is 270 ohms same size they look the same and you know they're you know look like they would just be the same same item so being 270 ohms same size i guess a lot of people are getting confused thinking oh the same choke 15 henries 129 x 30 henry's 120. quite a difference in the two chokes double the henries in this one so this is actually the uh you know the offending choke that would be the replacement this one is good uh this comes out of the 129 and this is the one i was thinking of replacing you know in this particular one here using it so this one reads 32 henry's on the gen rad so i'm imagining that the the faulty choke over here would probably be the same but i don't know because now i'm seeing the differences in you know this particular filter choking on this one so i've noticed something really interesting about this filter choke here and i'll take my wide angle lens off and maybe you can see that move close to it see the wire there it's just wrapped around the actual lead-in wire from the transformer the wire that comes off the windings wrapped around that wire and there is no solder on it so i'm thinking that that might be the problem with these chokes so i'm hoping because i don't want to dig any further so i'll open this side here and i'll get into this choke and uh re-solder both of these and hopefully i can get continuity again because you know the windings inside look pretty good and maybe i can bring this one back to life and get some concrete ratings and see what their differences are in uh the 120 to the 129 because there's a lot of as i say misinformation floating around on the net about these some people say you can use seven or ten henries and that'll be okay um well that's quite a bit different than 30. so they're only using 10 micro farad you know filter caps in this so there is a lot of inductance in there so uh you know if you're gonna take that down to 15 obviously you're going to probably want to think about the filter caps now they're only using tens in this too it says 10 10 and 10 and they're using you know these chokes but this one here has got more inductance in there i think they're using tens i'm not positive they might even be a little lower in the 120 so i haven't really looked into that i think i looked at the the parts list and they didn't actually mention what size the caps are the original cap was here but it's missing somebody was in here as we know and uh done a whole bunch of wonderful things to this 120. so one really neat perk about opening the 129 is i got the bfo cover out of it so the bfo cover i can just put here and look at that i can borrow that for now until i get into this 129 the 129's uh in pretty bad disrepair here put on my wide angle lens again i'm pretty bad disrepair the face is all carved up by somebody's fingernails and i do have a replacement face for this and all the replacement knobs reproduction knobs so one day it'll make a nice restoration project but for now it's going to be a parts donor for this 120. now there's uh they say the 120 was the improved version we can see right off the bat one different uh one different part of the receiver here is the band switching is made out of porcelain here whereas on this one it's just that standard wafer board material so they were thinking of trying to maybe make the oscillator a little more stable not sure how effective that was we'll see the stability in the end and they also have like a plastic lead through in here if you can see that in there's a plastic lead through whereas this one has just got a wire going through a hole which i don't think would be too bad so i might borrow some of the trimmer caps here or i might just look around in my stuff and try and find some but um i might bore some of these and replace what this guy you know hacked up here and tried to stabilize this receiver with um yeah lots of reasons that this receiver probably was unstable and i think a lot of it was due to these crappy tiny chief caps so that's where i'm at this point when i have some more answers on the filter chokes i will uh maybe make a piece of paper and get this mystery all straightened around so i've measured the inductance of this particular choke out of the hammerlin it's a 31 henries and 853 ohms that's a dc resistance and this one here i've managed to find a winding it's broken this lead here the red one goes in here comes back down and goes almost right directly into the the very center or not the very center but um the very end of the core and there's some small break in there so i'm very close with this one wire here and if you can see that wire i've kind of pulled out of the core there so let's focus on it and get my finger here see that very small wire there so i've managed to pull that out and from the green lead to there is almost 40 henry's it's reading 38.8 henry's there come on you can do it focus in 38.8 henry's in a queue of 11. but the dc resistance of this one is lower it's down around 700 and something ohms so this is almost uh i would say well you know they're 39 henry so this is probably a 40 henry choke that would uh you know make a lot of sense so there's a very few windings left i might you know be one small winding left in there so pretty positive 40 henrys 30 henries so this is what we're dealing with here there's quite a a difference here i would imagine the windings in this are you know maybe were changed and they've they've upped the thickness of the windings or something they've done something because these chokes don't seem to burn in the hq 129s but in these ones they do go and yeah as you can see it's extremely fine wire and at that amount of resistance you know this this thing is is um you know really uh gonna end up probably getting a little bit warm i imagine that this is probably broken somewhere you know close to here maybe on on close to the core or something like that it could have worked out or could have done anything who knows so what i'm going to do with this to make it good again is i'm going to connect a wire to this little broken wire and i'll disconnect this from where it goes into the core because obviously there was a problem at that point at one time and what i'll do is i'll run this wire over to here and that should make this choke okay to run again and then that other broken part of the winding because this is broken somewhere in there we'll just be an activist probably a few turns in there somewhere that just aren't going to be working so it'll be very close to the way it was and i'll be able to resurrect this choke of course you know i'll feed it with some voltage and make sure that there's no arcing and there are no shorts or leakage to the actual uh the actual core so check that all out and clean this all up so there is quite a difference so we're dealing with 15 henries here and 31 henry's here so it's 15 and 31 are the two chokes for the hq 129 x and you can see the resistance of that is 273 ohms and this is 853 ohms and then this one here is roughly 40 henry's and this one here is 30 henry's and the dc resistances i haven't marked down yet because i just haven't gotten to that particular point but um that's where i am i'll probably edit in a piece of paper here showing the differences of the two chokes so that'll go in right about here and you'll see the differences in the henries and the dc resistance here's the winding that i've removed from the actual core takes a little bit of fiddling to get that core off so this is an e in an i type core and you got to be careful that when you do take this core apart you're going to notice that there's a spacer under the eye laminate and you want to make sure that you don't wreck this because this is for core gapping and this has to do with saturation so you can do a little bit of research on chokes and find out what that is if you're not familiar with uh with a core gap and all that so what i'm going to do now is i'm going to reconnect this wire and then i will fix this core up so that it looks good again because i've done some carving there's carving on both sides of this and it's flaky like pie crust this stuff right so you can see that little wire right there it's coming out of the core and um so i'm gonna have to reconnect a wire to that it's very close to where it broke so i'm not really concerned about the remaining couple of windings they'll just be dead in there they won't be doing anything so this is where we're going to reconnect to and that should give us around close to 40 henry so we'll you know have our original filter choke back in the machine again and it should be okay i can also do a little bit of extra insulating to make sure that this doesn't arc out to the actual laminations here and that is very important so that's where i am at this point here's the repaired filter choke for the hq 120. you can see i've put a new wire in here and i super glued it to the existing varnished paper inside here it's very solid and then of course it has this on top of it and then under here there's a piece of kynar solder to that wire and it runs up to that little piece of winding that you saw poking out before that was tinned and it's soldered to that and it's lacquered and insulated underneath this here is the existing wire and it's stuck into the uh into the actual uh lacquered cardboard really well i didn't want to have to break that out to put a new wire in there so all i did was i just put a piece of the sheathing high heat silicone sheathing over top of this and that'll be just fine the wire is absolutely perfect so there it is the repaired filter choke for the hq 120 ready to go back into service again now that i've got the filter choke taken care of i can get back into the circuit here and try and straighten this mess around so we noticed earlier this one here said 6h6 they've got marked here and it's actually supposed to be a 6z7 it's stamped on the socket so that right there tells me that it's this schematic well so we can see there's two schematic variants see this 120x here and it has two 6h6s whereas on this schematic it's the same thing as an hq 120x but it's got a 6z7 and a 6f8 so what they've done is they've removed this 6z7 and replaced it with a 6h6 and still tried to use one gain stage in the 6f8 here they've got a 100k resistor on the plate lead which is pin 3 here whereas in the schematic there's supposed to be a 10k resistor here they've just got a 50k tied to ground with a cap running up to this uh noise blanking switch i don't know what the heck they've done there but you can see this 50k here runs out to a bunch of other resistors and and goes to the manual avc switch and so i don't know why they've tied it to the to the noise limiter switch i don't know what they've done we can see that this is clearly a 686 that they've intended to put in here we can see pin 8 and pin 4 are tied and then the lead runs up here to the limiter switch so if we look here pin 4 and 8 are tied which are the cathodes and they go right off to the limiter switch so they've definitely tried to copy this little part here so i don't know what they've done in here as i say this is all really hodgepodgey this isn't correct to this schematic and i could sit here and try and trace this mess and draw it out and try and figure out what they were thinking but um chances are it's uh probably some modification from maybe some magazine way back in the day a lot of magazines came out with modifications to these radios and how to you know maybe make the best of both worlds and somebody got in here and tried to do that or who knows what the story is but i'm going to restore this to this schematic here and i'd like to use all these tubes the 6d7 and the 6f8 and see what the performance of this receiver is like with those if you use this schematic of the two eight six h sixes you lose one gain stage in the audio you can see the six set six v6 here the grid line just runs right up to here and there's no amplification that just basically runs into the detector area whereas here you can see the grid line on the 6v6 goes into an audio gain control and it clearly is coming off the plate of the 6f8 and then the the grid runs up into the detection area so you know you're losing one gain stage by doing it like that mind you i don't think the gain would be too high it's only a 10k resistor on the plate but uh you know i don't know what they were thinking and i'm not even going to try and figure that out but i would like to just yeah see what they've accomplished and take measurements off this and play with this design here not this one because to me this one here seems like the chintzy design so here i go time to clear this area out here's the section i'll cleaned out you can see that the tube sockets have been almost all cleaned off i've removed the cathode resistor and the capacitor and all the wires and all the junk off of this that was all really confusing i haven't removed anything out of the bfo can because this appears to be correct it's just they've added two pink caps so i'll go in there and i'll fix that all up in the end and just one thing at a time here these wires up here all seem to be in the correct spot you can see those up in there those all seem to be in the correct spot and i've tried to uh put the uh the you know appropriate wires from the transformers in the uh you know the correct spots on these terminal tie strips here to get started this is the audio output transformer lead one goes to ground the other one goes up to this jack up here which i've completely removed in order to get in to this area here and see what else can i tell you i've removed the line cord got rid of that right now and disconnected it from here and disconnected the ac and uh got rid of all that so basically i've just kind of cleaned this whole area out i'll have to replace this wire that runs up to the top to the grid cap of the 6f8 it's crispy it's a rubber wire in there and it's all broken and um yeah just start over again and copy the schematic over here and turn this back to its former self so that's where i am right now the bottom half of this hammerlin has now been recapped and most of the resistors have been changed with the exception of just a couple so this resistor here is still factory or it's the original one that came with the radio when i got it it's 3000 ohms and it's the plate supply for the voltage regulator and the fixed capacitors i've left behind are the fixed capacitors on the oscillator coils you don't want to change those caps unless absolutely necessary and i'm not talking about the compression style trimmers in behind there's some red fixed mica capacitors you don't want to have to change those as i say unless they absolutely fail or something's haywire because uh many of the many times they don't tell you this but they're hand picked at the factory in order to make the actual dial accuracy correct on these old radios so if you don't fiddle with those you're probably better off there's a lot of things that do affect the dial accuracy now and a lot of it is just due to the change in the coil cue of the oscillator coils the forms are drying up and the varnish on the actual windings or the little wires there is changing and that all changes the queue of the coil and uh changing coil cue also changes the way that the band or the dial will actually align up so the whole idea is to get it as close as you can and usually they come pretty close still they're for an analog dial they're they're pretty good so you can see this whole section is put all back together again the two filter chokes are back in it's got brand new rubicon 500 volt 10 mic caps three of them i put a bit of silicone here to just to fasten them to this uh to the filter choke this is actually a ways off the filter token there's just a little puddle of silicone underneath there just so that these don't shake and vibrate around if you ever move the radio kind of thing so this is the uh the silicone it's a ge silicone too and it's the uh the non acetate kind of silicone it doesn't have that horrible vinegary smell it's a really mild smell and you'll find that that won't really harm the metals that it's applied to so you can look into that if you're going to be using silicones on anything you want to do use the stuff that won't cause any kind of metal corrosion so i found that for my own purposes the ge silicone 2 stuff works very well this one has no silicone under it because it's pretty you know it's pretty firm here you really have to move it in order to to make it move around so there's three brand new filter caps this whole section has been basically returned to stock again so the noise limiting circuit and the whole audio section here has been converted i've left one resistor out here for experimentation because i don't really like the value of what they've chosen and i know why they've chosen that value that's the 10k plate resistor on the 6f8 that 10k plate resistor is very low and if you uh have a schematic there you'll see on the schematic they have a 1000 pico or a .001 mic capacitor going to ground from that point well what that does is that kind of cuts all the highs out it really really limits the highs off in the radial and when i listen to radio broadcast i like to have a little bit of fidelity there i don't want it to be totally cut to communications quality so i'll play with that value and i may include the tips or notes in the end of this video and if i do forget something you can leave a uh you know a question in the comments and i'll and i'll answer it to the best of my ability and and try and help you out there the bfo has been completely rebuilt it's got brand new caps in here and that's all redone this tube here was originally a 6z7g i've modified the tube socket so that it will also take a 6n7 and that's the tube that i would prefer to use because it's a shielded tube and it has a little bit higher current draw on the filament but the the transformer in this hammer line is ample to deal with that the pin out is the same everything is the same about the tube it's a class b amplifier the 6z7 is a class b they're both dual triodes the pin outs are the same they're both high mu triodes the only difference is the 6n7 can deal with a little bit more power than the uh than the 6z 7g and or i should say that it has better dissipation ratings better wattage ratings than the 6z7 and it's shielded so i would prefer to use that tube in the noise limiting circuit here but at any point in time i can just pull the tube out and swap it in with another tube it's no big deal because they're wired the same pin one on the six z7 has no connection and pin one on the six and seven is the shield so pin one is now grounded so when i plug that tube in the shield of the tube will be grounded and everything else is in there a new cathode capacitor on the 6v6 new resistors on the cathode of the six v6 there's two 680 ohms which make 340 ohms they're in in parallel here so it's only 10 ohms shy of the original value the 6f8 uh when you rebuild this you know you probably won't ever have to go into such an extensive rebuild as i've had to do on this one this one was really hacked up in this area here but uh if you ever have to you know strip a section out it's a crucial to pre-plan the use of your terminal tie strip here because when you populate this tie strip you have to keep in mind everything that's going to be around and i left this one terminal open so i could tie the cap from the volume control to it and then from there it goes to the plate supply and that also gives me a tie point to tie in this plate resistor into the b plus lead so there's things like that that you have to kind of pre-plan the grid cap of the 6f8 comes through this rubber grommet over here and then comes out and it also ties to this pin here so you want kind of want to make things close to where they have to go and where they lead off so a little bit of pre-planning and you know you're you're kind of off and running in that way i've tested the resistance from the high voltage section to ground so the resistance from the cathode of the 5v4 to ground and the output of this rectifier to ground you always want to test the resistance before you fire one of these radios up because if you have a low resistance you know say a couple of k ohms or you know lower you are risk opening this choke again so the resistance to this in the high voltage section is very high right now so i don't have to worry about that it's there's no short circuits you want to make sure that there are no short circuits before you fire this up because this filter choke is a real sore spot in uh in these hq 120s so i'm beginning to see so now that i've you know basically found the the problem and tap that winding off i don't want to ever have to do that again so this is the reason i'm using some pretty good caps and everything everything should just be fine after this point i'm pretty sure so at this point i still have to put the 6n7 and i've got to go dig one out of my tube supply and this is a 6k8 converter over here i don't have one of those this radio was missing those two tubes if you recall when i first got it so i'm going to go dig some of those out i'll put those two tubes in and we'll turn the radio on and see if we can get any life now i haven't tested any tubes in this radial this is all just completely the way it came what you know er what i know right now is what you know and vice versa there's this you know i haven't fired the thing up it's going to uh this will be its maiden voyage so i'll hook an antenna to the antenna terminals down here the speaker is still inside i still left that speaker inside so i'll have to end up replacing that and in order for me to tune the if coils and go on the top of the chassis which i'll be doing next i do end up having to remove the case so i'll have to take out all the screws in the face and there's four screws on each side of the radio here and i can remove the case so i can get at the iaf coils the if coils they tune from the side and of course this is solid here so i can't tune them at all so the whole thing has to come right out and that'll be the next step so i'll go dig out some tubes and uh in the next little bit here we'll fire this thing up and see if we can make this thing work without any smoke okay well we're just about ready to try this out i've put the tubes in it i found a 6k8 and a 6n7 and now what we're going to do just before we turn this thing on is we'll center the antenna compensator okay and how when we first try this thing out we want to have the crystal selectivity off we'll have the phasing sitting at 12 o'clock we want this to sit on receive because if it's on send we won't hear anything the sensitivity will have maxed out we'll put this on 54 to 1.32 megahertz so it's basically most of the broadcast band in this position here the audio uh gain is not off but it's on zero if we turn it off the radio is off so we want it on zero we'll just have it down low and actually maybe we should have it up around four or five let's turn up around four or five so that when this thing comes on we'll actually start to hear something if it does anything i'll have the limiter off i i can have it on manual automatic voltage control or beat frequency oscillator will have it on avc and what the avc does is it automatically turns the gain of the sensitivity up and down automatically for you so by having this on avc it's set to a level to where the receiver doesn't distort but it's enough gain to make the receiver really work quite well so it won't allow it to distort really that's if the avc is working correctly so we'll leave it on avc so that just will kind of govern things and the beat frequency oscillator doesn't really matter because we're not on bfo but we'll just have it pointing at 12 o'clock so that's where i am so i'll focus this down here get the light off the face so that when i turn it on you'll start to see the dial lights come on slowly now i'm going to hook the volt meter up over here in the background it's on on dc and i'm going to monitor the high voltage section and make sure the high voltage comes up properly because if there's a problem in the high voltage section we don't want to risk hurting that actual filter choke now we tested it the resistance is high everything should be okay but who knows if something's going to arc out or something like that in here you got to remember in these receivers you're dealing with really high voltage this will be an excess of 300 volts inside this receiver so if you're working on one of these things you want to be very very careful you don't go touching anything while the unit's on if you ever repair one of these things or if you're following along you're definitely doing this at your own risk so be very very careful if you're not sure of what you're doing don't do it don't even work on one of these things because they they do they contain some really high voltages and when there's no load on the power supply they go very high so now what i'm going to do is turn on my variac over here i'll move the camera my big old variac on this side i've got the variac down and i'll turn it on okay i want it it's at zero but i want it to current limit so i'll put it on current limit and i'll start advancing the variax slowly and we'll watch the dial lights on the receiver and the voltage so you see we're at 244 millivolts that's basically just a static voltage there so i'm going to turn this on i'll start advancing the control you can see the dial lights are starting to come on that's a good sign and we can see the voltage will start climbing once the cathode of the rectifier tube starts to warm up and it's starting to warm up now so it'll start to climb and it's a good sign that it is climbing because if it wasn't climbing we'd probably have a short somewhere and it's climbing quite easily and that's really fluid too so there's no problems there oh it's just about up to 80 volts now you see it's going to climb down again the reason it's climbing down right now is because the rest of the tubes in the radio are warming up and they're starting to pull current so it'll settle off and then it'll start to you know it'll find kind of a an equilibrium like what it's doing right now so it'll first rise and then of course the other tubes as i say they're the they're starting to their emission is starting to kick in so it's starting to drag the supply down so i'll advance it some more and you can see it just climbs very slowly and it is fully current limiting now this particular radio uh has quite a bit of current draw there's lots of tubes in here and it does draw lots of current and you can see the lights on my control are lit you know not super bright but they are uh they are bright and they are lit up like that right now because it's current limiting so now what i'm going to do since i know that this is most likely going to be okay i'm going to throw the current limit switch to straight through so th stands for through on the switch but i'm going to turn the variac back down again so i'm going to shut this down and now i'm going to bring it up slowly with no current limiting and watch the action of this radio so we'll take a look at the the face of the radio and you'll see the volt meter in the background there again so what's going to end up happening here is i'll turn this all down all right bounce through so now there's no current limiting so i'm going to bring it up and here we go we have life already look at that ah that's fading out oh it might just be conditions so let's roll the dial around you can see the high voltage is pretty high it's above 300 volts so i'll just roll this around so now if we fool with the antenna compensator that'll tune the antenna and tuning the antenna is very important whenever you're dealing with anything in radio because having the antenna tuned correctly to the radio is matching the antenna to the receiver and by matching the antenna allows you to receive better so let's try tuning this and see what happens so you tune it to the loudest spot it's right about there nice thing yes meter is working too i don't know if you can see that in the camera the needle's moving a little bit there which is a good sign five centimeters over higher terrain with a low plus one not bad not bad for a first go no smoke and we're receiving radio signals it doesn't get much better than that so let's test some of the other functions let's make sure i got everything right here so when i turn the bfo on i should hear a whistle when i get onto a frequency so um find a frequency here so the bfo is working that's good now the manual it should get quite a bit louder when i take it off of avc because um that's not you know controlling there's no automatic voltage control anymore so i'll turn onto a frequency yeah it's getting louder and the needle goes down i'll go to find a stronger frequency in the world yep news 11 anytime so that evc is the abc line is working try the crystal selectivity see if there's uh if it narrows it up at all yeah the the crystal's working in the crystal selectivity boy it's really narrow keep grabbing this knob it's the wrong one this one here doesn't really affect anything right now this is what i need to be focusing on not bad so it all seems to be functioning right now so this is a very good start now keep in mind no tubes have been tested it has one new 6n7 and that's only the noise limiter we should try the noise limiter out i'll see um turn the audio again down turn the crystal selectivity back off see if we can find any noise when you rotate the band switch if you hear static when you rotate the band switch you can pretty much be assured that the oscillator is working so i'll turn this up yeah it's clipping the noise you can hear the difference so the noise limiter is working what i'm going to end up doing one day and i'll probably have another video on this is i'll make a random noise generator to test the noise limiters in these old radios so basically it'll be like an old commutator type dc motor with an antenna on it something that'll make a horrible noise and see if this can trim it out and uh that would be a another neat video to make sometime in the future so i'll probably do that and it'll help me test out the noise limiting situation i really it's quite quiet here all of our power lines are underground around here and i'm right at the top of a hill so uh you know i can walk up to the end of my street and see for miles it's uh i'm up quite high so this um so it's really relatively low noise up here so you can see the noise limiter is working so let's go back to the band switch again if you rotate the band switch and you hear static in each in each particular uh uh part of the uh the band switch you can pretty be pretty much be assured that the oscillator is working if it goes quiet you know like i'll go between here if it goes like that it's pretty much you can tell that the oscillator is dropping out so i'll turn it up and i'll rotate it yep it's working that's a little quieter but it's because the antenna compensator isn't picking up any there hasn't compensated the antenna here hasn't tuned the antenna so that's working no problems there yep see oscillators working in every position so i'm off to a really good start here everything seems to be working pretty much right off the get-go so now the next thing to do what we're going to do is open the case up go inside and start looking at the iaf section and start tuning the if and uh we'll look at it up here on the spectrum analyzer again we'll look at it on this spectrum analyzer here and see how wide the the factory if transformers are really are inside of this uh particular receiver with the of course no crystal selectivity on i want to see how wide they they are you know left well alone and of course and then we can check the crystal selectivity uh positions here and make sure we also have to um locate the actual crystal frequency itself so uh usually they're not right at 455. the if for this is 455 so i would like to i'm hoping that the crystal's very close to 455 and if not we might be able to modify the crystal to bring it to 455 because if you drag this too far from its original if it'll also that will affect the dial accuracy too and you don't want to do that so we want to keep it as close to 455 as we can but that will be the next step here's a quick video to aid you in realigning the dials on your hammerlin hq 120 120x 129x140x any of these particular radios and it's pretty simple so if you're going to remove the dials don't worry about indexing them because there's no need to first you'll have to have this cover off here of the actual variable capacitors if this cover has to get removed and of course you got to remove the face that's pretty self-explanatory remove the knobs and of course take the nuts off the shafts that need to be removed right down here to the headphone jack and then the whole face should come right off okay at that point you've got a couple of set screws on the main dials undo these set screws you know just enough so that the shaft is loose you have to undo it the shaft itself has a groove in it so you don't want these screws to get caught in it so undo them maybe a turn or two and the same with this one and then what you've done is you've loosened the shaft off and then they're usually pre-oiled or lubricated in the center you can just very simply slide them back they put grease in them from the factory it seems and then all you do is you pull this forward and of course with the gear being out of there and it's not yet so i'll push that back a little further and you pop this out now the edge of the dial itself here is driven off of two washers that are spring loaded on this main shaft under here and you'll have to get the edge of the dial back between those two washers that's not too hard with the use of a flashlight and you see the the two washers down in there you have to get it in between those two washers down there not too hard in the end when you push this gear back light back here when you push this gear back you can see it's going to it's going to come out of the main gear now you're going to lose spring tension on that gear now those two springs hold tension on this smaller gear and and it reduces the dead time when you're tuning it so there's no no slop in the gear so you're going to have to basically take these two gears and move them apart one one way and one the other until the spring has a bit of tension on it it's usually about halfway through the opening here and then you can lock it with a just a screwdriver or something put a screwdriver in the actual gear like so and that'll lock it when you're actually going to push this gear back in and put the dial back together so when you're putting the dial back together now you've got it out it's pretty much that simple and it goes for both sides so what you're going to do is uh you're gonna put this back in here and you have to get this right between those two uh washers down in the bottom okay so that takes a little bit you'll have to use a flashlight you can look down in here like this i won't bother right now because it's not too important in this video so of course you've got spring tension on this gear right now and i can't do that with one hand on the camera and one hand on the the gear here so so say there is spring tension on this right now and it's been locked what you do is you just push this gear here back in to the pulley or back into the actual dial i mean put it in like that and then get the gear in doesn't matter what position it's in at this particular point okay as long as there's spring tension on this gear so now you can see your dials back in now what you do is you rotate this dial you see this stop here on the back side of the dial you rotate that until it hits that see it hits that there rotate that till it's tight mesh the capacitor so this capacitor here is fully meshed okay so that means that it's at its uh at its um you know the lowest end of the band at this point so just mesh it so it's completely flush all the plates are flush you don't want it kind of half sticking out or you won't align it properly so make sure they're flush make sure this is at the stop and then tighten these two screws up and your band is realigned that's that simple so now this doesn't of course uh have anything to do with the rf alignment or anything this isn't going to get you your if the if the actual band scale is off uh according to the stations you have to go underneath and adjust the the the padding and the the trimmer capacitors i should say in the and the coils you have to adjust the the compression style capacitors underneath the chassis adjust the top ends of the bands and the coils adjust the lower ends of the bands but that's the same and it's the same thing for this one you'll notice that this one is at its stop on the other side so if i rotate this around here this is at its stop and you'll notice that this sits at 12 o'clock this one line here that's its alignment point to that black line on the window and it's the same with this one this is the alignment point here on that one so don't get it confused with this line here it's this one here and of course when it's at the stop this should be you know pointing at 12 o'clock and when this one's at its stop this one should be pointing at 12 o'clock and that's where you tighten these screws remember to fully mesh both capacitors they have to be fully meshed all right so that they're they're flush all the plates are flush with each other on this one and this one and then you can tighten down your screws and it's pretty much the dials will be ready for calibration after that point if you remove these dials be prepared to go underneath and readjust all the oscillator coils and capacitors underneath because your dial is going to be out if you remove these most likely at after this point so this is handy to do if you need to clean the chassis off or take the dials off and clean them or anything it's it's not a big deal don't worry as i say about indexing the shafts because chances are if you're restoring this radio it's not in alignment anyways and this would be before you do any rf alignment if you do an rf alignment then take the face off you're kind of going at it backwards so make sure you do the chassis cleaning and remove the face first and everything and then right in the end when it's pretty much solid and ready to go back together is when the rf alignment and the oscillator alignment and everything will just take place hope this helps all right so i've cleaned the radio up inside and out pretty much i've cleaned off the chassis and cleaned the face up as you can see i uh completely removed the face went inside the s meter tighten that glass up so it's now tight in there i re-blackened the spots on the meter because the they were kind of fading and the light was shining through them didn't look very well and i cleaned the dials up and took everything off and cleaned it now i'm just working on the knobs cleaning the knobs up i'll put the knobs back on and we can get into the alignment here so i've got a little trick to show you with fixing the knobs up and making the knobs look a little bit better and i'll show you that here in the next shot so if you've removed the chicken head knobs off your radio or anything that you've got really with baked like chicken head knobs you'll notice that a lot of the times on these old radios are yellowed or discolored or the paint's missing out of that crack there and you know there's you know they're not looking like they should anymore so you know eventually you know you'd like to end up with a product that looks like that nice and clean you see that how nice and bright white that is so that's a very simple process and i'll show you how to do that all it requires is some white out that's it so all you got to do i use this this big stuff it works very very well for me it's very simple just open the bottle up give it a good shake first you know open the bottle up and all you do is you take it and you just smear it right on there like that okay and then what you do is just let it sit it's very simple let it sit until it dries and gets hard and you can kind of if you want you know get rid of some of the excess on the edges it's not a big deal it's already drying though so and just let it sit like that for a few minutes and uh when i come back i'll show you how to make it look good okay so the stuff's dry now so all you do is take your fingernail like so and just scratch the excess residue off you can even scratch right over top of the line it won't even affect the line in the center of the knob so i'll just do this quickly it takes a bit of time to get all of the white with a white out off of the chicken head knob because you know it does find little cracks and crevices and you kind of have to clean it up a little bit so a q-tip is your best friend too you can use that and scrape with a q-tip you can see how that how that helps out you want a soft substance don't scrape it with a screwdriver or anything like that because then you're going to scratch your your chicken head knob up okay and you can also use a q-tip i've got a q-tip here and i use a bit of rubbing alcohol so i'll just uh put a bit of rubbing alcohol on it you don't want it dripping off the end but you just want the end kind of wet you can go in here and that'll aid in your removal of some of the the bulk of it of course you don't need to be as sloppy you can try and just paste it right on the line the nicer that you are with the the white out you know the better the the final product is going to be this is just a very fast demonstration to show you how well it works so you can see it's already coming together and looks very very nice it's much nicer than it was before you know in order to get all the lines nice and trim you know you gotta work away at it a little bit and uh once you work away at it and get all the little white spots off like this and then of course there's a little bit in there and a little bit on the end there anyways you get the idea just keep working away at it and eventually you end up with a pretty nice looking chicken head knob with a nice clean white line on it and uh much better than it was before all that yellowing and grossness and it really adds especially when you've got a nice clean face on your radio having that nice white line there really does add to it so there you go hope this little tip helped we're now at the point to where we need to tune the iaf in this hammerlin hq120 this also applies for the 120x the 129x and also the hq 140. they're all very similar and the if sections are are all you know pretty much tuned the same way so in order to do this alignment procedure properly you do need a visual means you will need either a sweep generator or a spectrum analyzer a signal generator alone and an oscilloscope or a volt meter on the avc line just will not work for this particular receiver and i will show you why and it will also not work for the 129 or the 140x so now what you see on the screen here i've pre-tuned the if here because this is about an hour and a half twiddling the iaf coils in order to get this response pattern and the reason it takes an hour and a half is because you have to figure out where the maximum sensitivity is and how high up on the scale that is and then you want to listen to that on a you know with some radio stations and go wow that's really kind of ugly sounding so then you widen the pattern out a little bit you widen it out a little bit more and as you're widening the audio response pattern here the center is going down the center is your sensitivity here and this is your audio response so as you're widening it this goes down and down and down so you want to find that happy medium to where you have you know the the you know the best audio response for a given amount of sensitivity and this seems to be the equilibrium point and that equilibrium point is if you look at the marker on the screen right about here is four kilohertz and the three db down point is about six kilohertz wide so that's about the best that you're going to get if you start to narrow it any more than that your audio will really start to suffer just due to the audio section in this radio and the way that the transformers are designed this is designed for communications quality audio and when you try and stretch out these transformers too wide you really do lose the sensitivity so now when i say that you really can't tune this receiver with just a signal gen and an oscilloscope or a volt meter um i've tried it you tried doing it with that method just for the heck of it you know just to see if we could do it and get around you know the manual and doing it like this but um there is one thing that is a real catch-22 with this particular receiver and that catch 22 is the crystal selectivity section now when you tune this one transformer here on the top this guy here this guy not only tunes a peak but it also drags this crystal around so when you're what happens is that you know you find the crystal frequency you're at and you go and pick everything up and you find that it shifted the crystal frequency again so you're like ah i gotta go through and re-tune the if section again this is of course doing it with the signal generator method okay this isn't the sweep gen this is the signal gen method and uh using the avc liner and oscilloscope so now you go through here and you repeat everything up again at the crystal frequency and you pick everything up to find that the crystal has shifted again and you're wondering why is this keep shifting you know because at this point you don't have a visual means and i hadn't hooked up my spectrum analyzer at this point or any kind of sweep generator at this point and it just keeps shifting and it gets really frustrating so you keep moving this slug around because this is the one that keeps doing it well i can tell you that you see how this shaft is broken here this is from the previous guy that's tried to align it and i can guarantee you that he did this with the signal gen method and he was moving this so much trying to find it because it keeps shifting he actually busted the uh the little shaft here where you stick the screwdriver in so i had to tune this with a pair of pliers so that is pure proof of the result of just a signal generator tune-up job on this another interesting thing was the set screw or the actual you know the uh the tuning screw in this trimmer capacitor on the side of the phasing control was also missing so i was thinking you know oh maybe they you know at the factory it was just you know used as some form of a gimmick and you know it was at its maximum capacity but then i again you know you look at this and you're like yeah well somebody's probably done that taking it out so and of course without tuning this visually there is no way to know where that little screw is supposed to be turned to on that trimmer cap a lot of these units don't have this trimmer cap and they have a black wire in the lid here that black wire does the same thing that this trimmer cap does and what you need to do with the black wire is not bend it out close to this tab don't do that leave it close to the center of the lid here and you move it back and forth with the visual means using your spectrum analyzer or sweep gen and you tune for electrical zero of the phasing control now not that's not the zero on the face that's that's the phasing control pointing at 12 o'clock that is the electrical zero all right so i will demonstrate this quite shortly and show you what i mean so don't move that black wire close to this you know to this part of the lid here because if you do when you put the side cover on it will couple to it and it'll change your response pattern so you don't want to do that so the if coils that you need to tune if this thing has been you know say your radio has been extremely uh badly screwdrivered before you got it and you need to tune the if section just to get a peek in the beginning that's fine you can use a signal generator for that all you want to do is peek these all up roughly to 455 in the beginning so this is one you tuned here you two and this guy this guy there's two down in here that you tune you tune this guy here and then you tune on the other side the diode output link which is right beside the bfo and you'll have to tune all of those you can leave the bfo alone until the end but you have to tune all these and bring it to a peak that alone will be a little bit time consuming so this is the response pattern that i got with the crystal selectivity off as i say it's about six cases wide at the 3 db down point and at the peaks here of the signal on the audio side bands here you'll see that the it's about 4 kilohertz is the peak there so that really sounds pretty good for communications quality and it's a nice even cut between losing the gain i'll try and edit in a picture here of a really sharp response pattern that i've tuned for and that sharp response pattern will give you more receiver gain but the audio quality suffers so it really is all about that balance so i'll tune the crystal selectivity control here to notch number one and that's how it looks so right there you can see like you know we're at about just about the three db down point uh i'll go to the display line here you can see the top here and then we go down to the about the three db down point you know somewhere in here without doing the math on the screen right now uh you know so really you're going to be looking at um you know say we're uh you know calling this you know 11 db so we're wanting to go 3db down so we're going to go 14 right that would be the 3db down point right there so if you look when i change the crystal selectivity so really the response on this right now if you look at the marker on the screen here you see the response is from here to here that's the response pattern that we're really hearing all the rest of this doesn't really mean anything right of course it needs to be there for the signal to exist but this is really where the audio is dwelling some people will go 6 db down but um if you go 6 db down your you like uh candies and flowers uh that's all i can say uh 3db down is about the reality point for for the way that the audio is going to sound uh 6 db down you're just you're living on hope so so there you go so this is the response pattern from here to here okay so now when i when i go to crystal selectivity number two you can see how much sharper that is now it's from here to here all right when i go to three wow look at how sharp we're getting you know from here to here now and then of course on four and five we get really really sharp tuning and we'll lose a little bit of gain here you can see it'll drop down and that's about what it does on the four and five that's normal on positions four and five if you have this tuned properly so there you go so now what i'll do is i'll explain how the actual crystal selectivity works on one of these radios so the center frequency of mine is uh 455 300 so that's the center of my iaf and uh that took a long time because of course the cans pulling the crystal and you know getting finding this this medium here so now the phasing control setting it at electrical zero is that trimmer cap on the side that we were just talking about or that black wire so mine was missing the screw and when i got it when i looked at my facing control like on the screen here that was sitting at 12 o'clock or electrical zero and that was supposed to be zero well that's not zeroed so when you put that screw in there and you tight start tightening up that trimmer cap you start to get the zero like this and you'll pass it you'll go over to this side so you want to get that electrical zero which is right about there or so okay so that is electrical zero without that screw and without a visual means there is no way to find that because you wouldn't be able to tell if you're here or here you wouldn't be able to tell you'll hear a little bit difference in tone but how would you actually know how to you know visually know that that is you know off to one side or the other you just don't so one you know very very important reason to have this visual method now you'll see when i tune the phasing control here you'll see how it'll pull a notch onto one side see that notch it's moving up and i can move that notch closer to the center or i can drive that notch away from the center or i can if i go on to the other side of the the center arrow which is 12 o'clock i can pull a notch up on this side so say i'm listening to the frequency right now wherever i am i'm listening right at the center so i see i've got an interfering cw signal beside me i can move this notch up if the cw filter signal is right beside me i can move this and put him into the notch okay and kind of notch him down as you see i can move that notch further and closer from the center here you see i can kind of bury kind of a signal into the notch there you see that and i can do it on the other side if he's above me or below me i can do it on this side too i can kind of just you know create a really really tight notch there and that's exactly what this is designed to do you kind of just want to get rid of the adjacent frequency that's really close to you now cw which is uh you know morse code is just a pulsing carrier so if you're if you have him tuned right at the center he'll get really loud because he's right at the peak of your iaf he's like he's like right there he's a great in the center so the nice thing about that is really on the super tight selectivity thing here you can see how tight that is you know i can move the notch here see how i move that around when you tune him in with the with the main tuning control the whole idea of tuning him in i'll use the the marker as a as a a reference here so i'm tuning around the band and all of a sudden look at how fast he comes up and boom the cw is right there now he's going to be really loud and as i roll past him he's going to get super quiet again because he's just going to fall right off you see that so that's how the the the phasing works and the crystal selectivity works is whenever you tune a cw signal in or even sideband on you know on the on the wider kind of controls that's two and that's one there you can really as you're tuning them in you can really narrow right into them and get rid of adjacent frequencies by using this as kind of a notch and that works very very well so that's how the phasing control really works on these radios and why you need to actually tune this with the visual method so i very rarely use the crystal selectivity unless it's you know really hard copy in the morning or something like that or even in the evening or whatever i'll you know i'll rarely use it i used to be on cw quite a bit and that was really quite handy in those days but now i'm just you know basically an am guy and i do some side band too listen to side band and and um you know i will use the crystal selectivity maybe on this position or this position in order to uh get rid of some adjacent frequencies but it really is quite a handy filter and when they're tuned right like this they really really work quite well and in the end when i'm cruising the band i'll demonstrate all of this and uh and show you how this all works so that is really how to tune the if section of this radio in in kind of a nutshell i would go through it and uh you know have the camera on this but you would be watching me for about probably a half an hour or so tune this from nothing and uh trying to get a single you know really good response pattern and at the same time i have to locate the the crystal frequency and then drag everything over to its frequency and um you have to figure out how to do this without um you know moving that one transformer and dragging it off and that takes quite a bit of time and unless you actually do this with a sweep generator and fool with it for a while there really is no way to to explain this it's just so much that you have to know moving from coil to coil and moving back and forth and what i mean is is by uh getting your selectivity response by moving from this slug down here to this slug here to this slug to this slug and then back to this one or from this one here which will pull everything over and pick things up and then going back to this slug or to this slug or to this slugger to this lug and then over to the other side to the diode link it really is uh it really is an in-depth procedure so a visual method is the definite thing to have so next we'll be on to the rf tuning and um and aligning the radio so i'm getting to the point of to where i'm going to start rf tuning this radio here and i figure okay and i'll go through the the section here and check everything and you know look at these particular caps here to see how good they are and this that and the other and i you know it never ceases to amaze me how some people modify radios and this is a this is a pretty good one so what happens is is the part you stick your screwdriver in here like in a normal pattern here is always connected to the chassis so there's no you know connection between you and the actual coils because you know if if it was the reversed way the minute you brought any kind of uh screwdriver with even a little metal insert in it you know towards the high frequency coils it would drag it and you'll cause it to drift you wouldn't be able to align the dial up right so i'm checking isn't that i wonder what side this guy has attached these two you know as you can attach it to the chassis side you know the side that's supposed to go to the chassis which is this side right because you stick your screwdriver in here this is supposed to be the grounded side and uh you know or or what's he actually done so you know i figured i'd remove one of the wires and just check this out and um so this is the part that connects the actual wire on the coil hear that that's continuity so this guy has installed all of these capacitors these variable trimmers for the coils he's in installed them all the wrong way so there's no way you can use a plastic tool on this or even a ceramic tool because these are so sharp i don't know if you can see inside this thing i'll get my light up here maybe i can shine a bit of light on it so that it'll focus on it i don't know if you can see that but uh they're like razor sharp in there you can't actually you know put any kind of tool in there except a metal tool and that's just the way these are supposed to work you're supposed to actually use a you know a small sharp metal tip screwdriver and this side is always supposed to be the grounded side so it doesn't matter right you know it's there's you know it's not going to make any big difference well trying to do any kind of alignment on this if you bring any screwdriver near this the minute you touch it it's going to drag the dial right off because you're adding inductance from the actual length of the screwdriver to this and you know you're basically adding a big air pad or air capacitor off the coil up into midair and you know you could even be capacitively coupling it to your hand if you're using a small metal screwdriver or something like that so now it's okay to tune these with an insulated metal tipped screwdriver these ones here you can tune no problems because this side is ground okay so this is grounded right to the chassis and there will be very very if any little coupling between the screwdriver and what you're actually tuning so this thing here these are all backwards these are in here so with the minute you touch these it's going to drag the coil big time and uh you know it's just i don't know what people are thinking when they're making these modifications like i mean that's just you know absolute silliness so as you can see here on my little meter i don't know if you can see that there i don't have to push any buttons with this meter it just knows that i'm thinking it's kind of neat see that there i got a glare on it from something from this lamp here okay there you can see you know right on the back the side that soldered to the coil see that just a dead short right so the side that's supposed to be is you know this side to ground and you can actually see it you can actually see it's actually physically connected to ground so all these are all backwards so i'm just going to take the ones out of the hq 129x and i'm going to put those ones in here and i'll just mark down the values and replace them when i work on that because of course this is the receiver i'm focusing on right now and what the hey i still you know have to put this uh you know filter choke back in it too so so i've got my work cut out with me just reassembling that thing so so here it is i got to change all these out before i start doing my tuning so uh note to self and note to everybody else always check these if somebody has ever installed some replacement uh trimmer caps in here make sure they're the right way and you'll have to disconnect this wire to read it because the coil will just give you an actual continuity to ground itself because it's going through the coil right see that so you have to disconnect the lead to the top to actually check that so with these ones you can actually see they're just you know solder to ground you can physically see the connection here along all of these so what are people thinking you know like you know this is such a silly modification you know at least put them the right way if you're going to change the caps no wonder this guy had problems getting this thing to tune maybe that was half of the problem uh who knows man people hi there we're now going to align this hammerlin hq 120 radio and first thing you're going to do before you start the alignment is you're going to build this little adapter for the back of your radio to make your radio think that you're feeding a 400 ohm antenna to it most signal generators nowadays a 50 or 75 ohm output and you want this in line with the hot lead into the antenna jack in the back so one of your antenna jacks will tie to the chassis and that'll be ground so the negative of your signal generator will attach to that or their shielded braid will attach to that and then the hot side of that lead will go to here and then this will go to the antenna jack so you need to build this first if you skip this part your sensitivity of your receiver will be down if you tune it to uh an impedance of 50 ohms on the input it's supposed to see 400 ohms second thing we're going to do is go to the dial of your radio and where it says 200 you're going to adjust the band spread to where it says 200 so you want that at 200 right on the nose before you do any alignment if you don't do that your alignment will be completely off you can zero your s meter or put it to the arrows you can see there's an arrow here there's a procedure for that there's two vrs on the back of the radio one will adjust the top and one will adjust the bottom so at the top you can see it's on the arrow and at the bottom you can see it's almost on the arrow it's moved a little bit that's absolutely fine as long as it's relative and it's you know centered enough so with the rf gain or the sensitivity at zero it should sit like this with no antenna and with the sensitivity to its maximum it should sit like this right at the two arrows okay that aligns that meter you know just roughly get it doesn't need to be right on the arrows for the alignment as long as it'll you know show you relative sensitivity you're you're on your way so the crystal selectivity is off phasing is uh at 12 o'clock send receive is at receive your sensitivity is maxed this is wherever the dial needs to be this is on the band you're going to align we're going to align the 1.32 to 3.2 megahertz band audio gain is you know somewhere relative where you can hear some noise limiters off avc is on and beat frequency oscillators at zero and you can have this at 12 o'clock to start the antenna compensator okay so now we need the data sheet in order to show us where all of these adjustments are and what what coils do what and what trimmers do what and that's on this sheet here you can see it says rear of the radial that is the rear of the radio and that means that this is going to sit up like this and that's going to be like this so they match each other from the page to this now before you go sticking any tuning tools in here you need to have an insulated tuning tool and you're doing this at your own risk there's a lot of high voltage in here and if you slip you might buzz yourself really good so you need to be very careful if you're going to adjust this radio or work on it at all you're doing this at your own risk insulated insulated tuning tool for definite sure it can be a metal shafted tool the plastic ones you'll find won't turn these it'll break the shaft off so it does need to have either a metal tip and be insulated or some form of a screwdriver just do not touch this because as i say if you slip and come across that there's 300 volts there and that's 300 volts dc you have to be very very careful okay so now we're going to do is adjust the bottom band we have it on the 1.3 to 3.2 and that's right here on this piece of paper so we see that we have three coils to adjust this band this first section is the oscillator section this is what aligns our dial accuracy and that's the front end here okay the second one is the rf alignment which just picks up sensitivity and so does the antenna so that's what these all do so we can see the rf this is either the oscillator rf and the antenna so what we're going to do is align the bottom end of the band first because it's usually the one that's out and there's many turns of these coils you have to make to align them at first so what we're going to do is go to the 1.4 mega cycles here on the on the dial it says 1.3 to 1.32 to 3.2 that just tells us the band this is our alignment point so it says 1.4 megahertz here so we have to tune our main dial here don't touch the bottom band spread leave it at 200 don't touch that at all throughout the entire alignment move this to 1.4 okay so we're at 1.4 megahertz right there okay now we need to go up to our signal generator here and tune see where it says 1.4 we already have it entered and it's at 30 mod so we can hear a tone and i have 30 micro volts coming out of this cable going into that little little adapter on the back there okay so now we we can't hear the the signal so what we're going to do is tune this coil right here until we hear a signal and drag this actual band around even though we're not moving this dial we're moving it with this coil okay so i'll turn this now so now i've just aligned the bottom end of that band now you'll have to go back and forth and do this a bunch of times because what happens is it'll stretch the band out one way and move it in or make it shorter and i'll show you that here in just a short bit so now we'll go back to the second one back here because we've adjusted the oscillator to bring it onto alignment so now we go to the second one back which is this one right here okay and what we're gonna do is tune for a peak look for maximum signal if you pass it you got to go back there it is that's our maximum signal okay so now we'll go to this last one and tune the antenna this is really affected by that little rma thing if you don't have it and there you go and then you can check to peak it see how sensitive it is by tuning the antenna compensator and there you go so that's where sensitivity sits on this band okay so now that's the bottom end of the band but now we have to go and adjust the upper end of the band and that's at three megahertz so we tune the dial here to three megahertz okay so we want to get that radon three which is right there okay so now we need to tune our signal generator here to three megahertz pardon the glare of the lights here so three oops i'm on modulation i'll go here to frequency we can see frequency three megahertz okay so now we're at three megs but we don't hear a tone here again because it's not on frequency up here either so now we have to adjust this capacitor in order to bring it on very easy to pass see how touchy that is so there we go okay so now we have to align the rf stage which is this one here to bring up more sensitivity that's right about there and then we can try this and we're about the same on both bands there okay so now the antenna doesn't have an adjustment for that it's only the bottom end of the band okay so now we need to go back to 1.4 megahertz again on this band and check it to see if it's moved because a lot of the times it will move now so we'll go back to 1.4 megs here we're at 1.4 megs on the dial and we'll type 1.4 megs in here 1.4 megahertz and we're really close but it's still off so we're gonna go and readjust this coil again see that you can hear it how it was tuning in and we'll adjust the second one back here make sure that it's in yep and we'll adjust the antenna coil on the back here now we have this at 12 o'clock that's why it's taking such an adjustment so i need to recheck that again so move that and then i'll try and adjust this for a peak and that's at its peak there so then i'll recheck this one here because i moved that this is what happens when you move the antenna coil you have to remember the antenna compensator you got to remember to bring it back or the antenna coil adjustments this only affects the bottom two portions of the band so that was it so there we go so that's okay so these this the rest of the bands don't have it it's just two these two for the two bottom bands is the only two in the back you gotta remember to have this at twelve o'clock or you'll not have this centered so there we go uh now what i'm gonna do is go back to the three megahertz part three megahertz and we'll check the upper end of the band and see if it's still on i see it's a little bit out again so we need to go back and do that and that's where these things get fun to tune you see because you got to go back and forth until it puts it into alignment should be holding this up a little bit and that's this one here and then we'll go back and peek this one here there's none for the antenna this is just for the other stage for the uh rf stage and there it is so now we'll go back to 1.4 again and check and see if it's on alignment 1.4 1.4 there we go so now we know that we have our band line and that's how you align one of the bands and they're all like that so there is a couple of tricks though to this and when you get into the higher bands when you get into like the 18 to 31 megahertz band there's a lot of coupling between the rf stage and the actual uh oscillator stage so you'll tune the rf stage and it'll drag the frequency off so what you do is you pre-tune this until you find you know the the frequency and align the band bottom into the band and the top end of the band for the 30 18 to 31 megahertz and then you know tune for a peak here until you get some sensitivity disconnect your antenna at this point so it's aligned so your band is aligned to your signal generator disconnect your antenna go to the bottom end of the band and tune this until you get maximum absolute maximum static okay so tune that for maximum static and then go back because it's going to pull the alignment off and then go through again and align this again and then go to the top of the band and tune this one in obviously again to realign the top of the band and then once it's the top and bottom are aligned again go to this trimmer and tune it again disconnect the antenna from your signal generator or the uh in your signal generator from the antenna jack and tune this one for maximum static then go to the bottom end of the band and tune this for maximum static and go to the top and then they should balance out and once you find maximum static on both of these then put your signal generator back on here again and align these and you should be right on the spot okay that's a little bit of a trick with these things and another thing is you'll hear image frequencies with this one when you tune this one so you'll tune it and you'll hear you'll come across it'll go and you turn it a little more it'll go and you're like what the heck it's doing it in two spots how can it do that well that's imaging it's it has a bunch of images on here so what you do is you usually tune the stronger image and i found in this radio that the stronger image is usually closer when the slug is closer to the bottom of the coil so you can wind this in quite a ways and then the first first tone you hear when you're tuning it in is when you're on frequency the second one will be a little bit weaker so you want to do that if you don't do that your your band will be weak so it'll take a little bit of fiddling around and what i usually do is because there's so much they call it interlock between the two on these upper bands what i do is i start with the bottom end of the band first so i'll align the bottom end of the band and then i'll move right up to the top end of the band here and then i'll work my way up to the uh 18 to 31 position so this is the bottom end here all right this is the second band up and then you go uh the third fourth fifth and then sixth and that's kind of the way you wanna do work your way up and work your way closer to the top band because this one here is very sensitive to anything and when you put the bottom lid back on this radio it will shift that band just a little bit not too much but you'll hear it if you have a bfo note on or if you're listening to a frequency say around 28 megahertz and you put the bottom cover on it'll go right off frequency but it won't be that far so it'll be just a little bit and that's just the nature of the beast that's the way that these guys are but once you get the thing fully aligned you'll find out that it's a you know pretty darn good receiver and it's actually really fun to operate too so that in a nutshell is how you pre-align these or align them make sure yours is in the case mine isn't in the case so you want the black case on your radio first because uh when you put the case on it might twist or contort the chassis and that will cause frequency drift so any kind of torsion on this at all like it when you're even pushing your finger on it will cause that 18 to 31 megahertz band to move even putting my hand close to it like this you can play it like a theremin it's that incredibly sensitive so you want to have it in this black case you can't do this without the with the bottom on so you have to have the bottom on the only two antenna adjustments are the bottom ones the rest are fixed for the for the other bands and as i say just go through and do that with all of these remember the maximum static thing though because that is really crucial in getting these things to maximum sensitivity on the upper bands the lower bands aren't so particular for that but the upper bands really rely on that tuning procedure so as i say align the oscillator first make sure that it's you know on the frequency that your band is aligned like what we did on all the bands and then go back to the upper band and then go to the lower part of the band where the alignment is in tune this and tune this for maximum static and then as i say go to the upper part of the band the highest frequency you're supposed to align it and then tune this one for maximum static of course this is for one band and this is for another band and then this one's for another band so that's how they all work and then after that you'll uh you'll be dealing with a uh you know a pretty decent um pretty decent receiver there you go hope this helps here's a quick example of how well the noise limiter circuit works inside this hammerlin hq 120x so this is with no noise limiter on and this is the circuit with the 6z7 in it all right i've subbed mine with the 6n7 it's a direct plug-in and it's a shielded tube okay so i'll turn the noise limiter on here and that's with the noise limiter on you can hear in the speaker here how nice and mellow that is now and it'll reach over here again and turn it back off you can see on the scope what a dramatic difference that is that's with it back on again so that's a pretty impressive noise limiter and it really doesn't affect the intelligibility of anybody's speech or anything you almost don't even know the limiters on when you're listening to a radio station so it does work very very well well this hammerlin hq 120 radio project is finally coming to an end and quite the restoration project it's been as you've seen in the video but well worth it you know it really is quite a handsome looking radio i think is that pile of rubble you see in the corner is all the parts and pieces that are out of this radio there's lots of stuff that ended up on the floor and some stuff that's not in the pile like the speaker and the line cord and stuff but you know that's pretty much the just of what came out of it it really is quite the performer now that it's aligned and completely rebuilt and what we're going to do is head into the short wave bands in the broadcast band and check out how well it actually works here we are at the bottom end of the broadcast band and it's the night time here so that means that we have conditions now if you remember what we talked about in the beginning of the video how and when conditions are happening it's kind of like that rock skipping on the water or the signals you know going up to the atmosphere and then bouncing back down and coming down in different parts of the world well it's doing that on the broadcast ban right now and i have signals coming in from all over north america on the broadcast band so right now we're at .54 mega cycles or 540 kilo cycles and will coast through the band with the main tuning we'll leave the band spread alone because that's fine tuning for a lot of the other bands but not for the broadcast band it really doesn't do anything for that band so we'll leave that at 200 and we'll just play with the main tuning and i'll just quickly coast through the band and give you an idea of how many signals there really are coming in right now and uh this receiver is pretty sensitive to all of them so it's uh it's listening to lots of signals from all over the place right now so i'll turn up the audio gain particularly shocking given reports that girls possibly and all close to the band may have been forced to cutting edge reports from those in the true epicenter of the conflict that's saw a vehicle flee on a public road outside the area's perimeter audio espn analyst tom waddle trap hot spots the patriots are probably one of them and that gives you all that you need to take those steps toward what he is saying to do so you can see i'll just stop here on the band you can see how many frequencies there are and it just keeps going and going and going as we roll up the band right now we're about uh you know we're only at point eight two says 820 kilo cycles right now or 0.82 mega cycles however you want to look at that so we're really still low on the band we have you know a lot of broadcast band to go through yet and there's just so many stations so if you have a receiver like this you can just you know at late at night you can slowly coast the band and you can you know really look for that that bizarre radio station dx sometimes you even find pirate stations in here the stations that aren't supposed to be on here that really are so there's a lot of conditions in right now on the lower bands the upper shortwave bands right now aren't active whatsoever they come active in you know certain different parts of the day they're the odd strong frequency every now and then but uh for the most part the upper bands really aren't all that active so what i'll do is during the daytime i'll come back and i'll let you hear the broadcast band again and you get to hear how clean it is because there'll be none of this conditions going on it'll just all be local stations and we'll listen to some of the local stations and we'll also crew some of the shortwave bands at that time as i say because they're just not active right now we're just getting here static so it uh all the different bands they come alive in different parts of the day the lower the later the night usually the lower the band and um right now the the broadcast band and the 160 meter band would be the ones that would be active here we are on the broadcast band during the day time so there's not so much skip or conditions coming in so we can focus a little more on some of the more local radio stations so keep in mind now i don't know if i mentioned this before but when these radios warm up you might notice that the dial might not be right on the marker it might be on either side of the marker and that's quite normal because these radios they really go from stone cold to easy bake oven and i usually align these about 45 minutes into their warm-up cycle that's about a happy medium so usually they're on you know either one side when you're lining them and they move to the other side or vice versa and that really depends on the radio you're aligning and how the radio you know when you're aligning it how it feels you can really watch how it responds to your alignment after a certain warm-up cycle so sometimes you know people will align them a little bit before the dial marker so that they kind of come on when they're warm and sometimes when they get really hot they'll go just a little bit over the dial marker and what i've done with this one is i've found kind of the happy medium so that it's usually with you know within the dial marker just a little bit of either side and that is really quite normal for all of these particular receivers you got to remember there are no crystal controlled oscillators or plls or anything inside of this radio this radio is all free running oscillators inside and as i say it goes you know goes from just about you know room temperature to really really hot because the lid on the top of this radio stays closed there's very little ventilation on it and this really is uh you know a coffee warmer this radio you could put a cup of coffee on top of it and it would keep it warm this radio really does get quite hot i can feel the heat coming off the face of the radio already and it's been on for about an hour and a half right now so that's absolutely normal with these radios for them to move around like that so if you perform an alignment chances are you've done your job right it's just the radio that's the way that they operate they move around a little bit so what i'm going to do now is i'll tune around on the am broadcast man and we'll listen to some of the more local radio stations and get an idea of the quality of the sound here we go in the world song and presidential inaugurations and even olympic ceremonies in atlanta dr king's daughter bernice invoked recent police killings saying many have been gunned down so you get an idea of the sound quality there welcome back to the 180 on cdc radio one i'm jim brown celebrating it when it's all said and done for the pacific highway also a 45-minute wait so busy pick your poison both but the names will stay the same all right how about this director's adelphia it's classic i love your enthusiasm but i'd rather be healthy energetic and fit join us on texassuperfood.com or call us at 844 so this radio station right here that you're listening to is about 300 in miles wise away so about 300 miles uh you know i guess that would probably be a you know driving wise anyways so that's pretty good for the daytime when there really is no conditions and you hear the fluttering that's underneath that radio station that is the fluttering is another radio station competing this with this radio station for this frequency so you can imagine how far away the other radio station is enrollment is open here as i said expert advice plenty of options make choosing the right appliances much easier about 20 to 30 depending on what they are so baseball notice max schurzer heading to washington setting your deal with the nationals worth 210 that's just somebody not having enough uh color palettes it's 10 and downtown it's 10 as well news 11 39 233 sounds like conditions might be changing that's a pretty far away station sounds like it uh could be coming from mexico or something like that so conditions are already moving around and it's only midday here but that gives you an idea of the sound quality and the sensitivity now this receiver right now is hooked up to an 80 meter inverted v so the antenna is completely non-resonant on the on this you know broadcast band right now so that gives you an idea with just a random wire of how well this radio really does work so what we'll do when i come back is we'll head to the short wave bands and we'll look at some of the really high bands say you know the 10 meter band and around there and see how it receives up there that's where these radios were known to not be too incredibly sensitive so let's see how sensitive this radio really is on those bands here we are on the upper short wave bands so this is just underneath the 10 meter band and this is called the 11 meter band which is the citizens band and a lot of ham operators use this particular band in order to see if the upper bands are open it's pretty active so this is where this receiver this is really at the top end of this receiver so let's see how sensitive it is on an 80 meter wire there's no 11 or 10 meter antenna hooked up to this this is just really looking like a random wire at this frequency right now or at these frequencies so let's check out the sensitivity pick up the tuning here i use this for fine tuning up here just just rock it a little bit four five six people you need a fish upload over so that's one frequency that's active in the uh on the cd it's a really small window on the dial here where where it's um actually active just cruise in here and see if i can find any uh big signals there it is there's some big signals there they're all on top of each other they're all talking at the same time so chances are they're trying to talk to the same person somebody that's obviously pretty far away you hear some of them are pretty strong in there you can tell that um they're probably running some form of power on the 11 meter bands you can tell by the sound of his compare he's a carrier he's pretty compressed so there's probably some sort of uh heavily driven amplifier should we say in there this is the 10 meter band i think it's pretty quiet right now 10 meter band really starts around 28 megahertz a little bit of cw i think that's a beacon again this is a little bit of a beacon i can hear some other cw in there too you can change the beat note by moving the beat oscillator around now you have to keep in mind that also when you take this off of avc or and put it to bfo or manual you have no s meter action anymore it shuts the s meter off so when you're listening to sideband or to any sort of uh cw note on the bfo you won't hear or you won't see any s meter action at all it'll just rest down at the bottom that's normal for these receivers in here nice and stable that is receiver is really stable up on these bands at least when it's rebuilt they are you can sit and listen for uh you know listen to a uh a single sideband transmission for a long period of time without having to readjust once they're warm they work very well but you have to let them warm up that's very important oh lots of uh lots of people talking at the same time down here lots of compression going on in there and that's crunchy be nice to find a cleaner transmission that's a bit cleaner so anyways you get the idea and crumbled up cornbread in there stir that up chop me up some onions chop me up a little bit of jalapeno peppers in there and then pour hot bacon grease over the top of that yikes that doesn't sound too healthy anyways we'll head on down to the uh 15 meter band and check out the 15 meter band see what we can hear down here oh i went too far that's the uh this is the wwvb or wwv sorry on 20 megahertz so that's the international time signal or just the time signal here nice and strong that is so when these are tuned well that gives you a really good idea of you know the signal strength on the upper bands they do really work quite well so anyways i think that's uh a pretty good example of all the bands anyways i could keep tuning through the bands here forever and listening to uh broadcasts and stuff but uh this is uh you know i think probably i'm not sure how long this video is gonna end up being i think i've got probably five or six hours of footage i have to sort through here but i really hope you enjoyed and i hope this gives you some insight into the way one of these old radios really does work and they are really a pleasure to operate when they're working properly they're really fun to cruise the band late at night and find all of those uh hidden little frequencies and and things like that i have a neat little uh thing that i'm adding to this radio and i will do another video on it and it'll really help you find all the little hiding frequencies the ones that you can't even hear you'll see and that will be the next video so i hope you enjoyed this and if you did give it a thumbs up and stay tuned and i'll have some more of this crazy stuff coming up probably quite shortly alright bye for now you

Channel: Mr Carlson's Lab

Views: 1,473,186

Keywords: Hammarlund (Defunct Organization), creativedesigncomponents.com, creative design components, Hammarlund HQ-120-X, tube receiver repair, receiver restoration, antique radio restoration, antique receiver restoration, electrical restoration, Radio Receiver (Invention), old radio repair, old receiver repair, Radio (Invention)

Id: J31nVC0ms0w

Length: 157min 22sec (9442 seconds)

Published: Thu Jan 22 2015

Reddit Comments

[u/lorens210]

Good job! Back in the day, I had the U.S. Navy version of this receiver called the RBG-2. For HF CW operation, it had wonderful band-spread.