BEAUTIFUL 1940's Majestic Radio Receiver Restoration!

hi everyone and welcome to another episode of mr. Carlson's lab today we're gonna restore a radio from the 1940s this radio was made by the Majestic radio corporation it really is such a nice looking radio that it does warrant a full restoration so not only are we going to repair and restore this radio we're gonna make it perform the way it performed when it rolled off the factory production line so together we'll bring this radio back to life so grab your favorite snack sit back and enjoy as I take you through the entire restoration process all right let's see what we're up against today here you are sitting right beside me at the bench let's bring this thing back to life together let's make this thing perform the way it did back in the 1940s so the first thing I noticed about this radio receiver is this looks it has a really attractive design to it whoever designed this radio did a really really nice job it really does stand out above a lot of the all-american five radios another thing is is this thing looks like it came out of the box the finish on it the paint everything is so incredibly nice now at first glance you look at this and you'd think wow you know brand-spanking-new radio or something like that and then when you look a little bit closer there are no runs the paint is perfectly even the finish that they chose for this is a satin finish looks really really nice this radio here's the thing this radio was issued in this color and it was also issued in walnut now what tells me that somebody painted this thing is look at the bottom I see some runs and somebody didn't mask this off very well if they would have taken the time to do that and clean everything up it would have been you know very very hard to tell that this was actually painted whoever did this did an incredibly nice job aside from these steel runs on the bottom again this is gonna be down like this nobody would ever see that right but other than that as you can see like it's just you know the paint is really looking around the radio on topsides and even down in here you know there's just there's no flaws whatsoever it's just on the bottom it's a really nice job another interesting thing about this rate is if we look the speaker cutout is on the side of the radio they didn't put the speaker in the front of this radio or on this side which is kind of a neat idea because a lot of the times these things sat in the kitchen and when they sit in the kitchen they're usually facing the person that's doing whatever they're doing in the kitchen and food splatters on these things and liquid splatter on these things I've had quite a few All American five style radios with liquid damaged speakers so if anything was to ever splash on this thing chances are it's not going to damage the speaker so when we open this thing up we're going to discover all of the issues with this thing together here when I open this thing up we'll see if the speaker is in good condition or not now there always is that chance that you know some technician over time isn't poked his finger through it or drop the screwdriver on it or something like that but I sure hope not it died it sure looks like it's in just you know fantastic condition on the outside on the backside of the radio this looks like this has been wiped down with some cleaner or something like that you can see that's really faded another interesting thing here it says re-examination service underwriters laboratories interesting so way back in the day these things got really interesting as you can see here you see the paint right here so it kind of tells you for sure that the thing was painted if it was just sitting and you couldn't actually touch this radial field was sitting behind glass and was just sitting there like that you wouldn't know really it is that nice and I'm hoping that is portrayed through the camera so again you know looking at the bottom it's definitely tell it was masked off and we can see it looks like overspray or something on the inside here you can see that so when we take the back off and take a look inside we'll see what's going on inside there I'm excited to do that because at this point you know as much about this radio as I do aside from just looking at the aesthetics of this thing on the face here the dial looks nice and clean there are no cracks in the glass that's a real bonus nobody has wiped off the numbering and lettering on the inside that's something that you always have to be very very careful with on these radios when you clean them on the inside sometimes water will take this stuff right off so you have to try you know a very mild cleaner and sometimes just water itself in a very inconspicuous area because there would be nothing worse than rubbing an area and say you took the 160 off or something like that I have horror stories about water decals I had one one dial with a water deckle on it and I didn't know it was a water deckle and I rinsed it with water and the whole dial just floated off that wasn't a good day that was way way way back when many many many years ago so in order to get inside this thing it looks like I'm to take off some screws usually what they did with these is they would fasten them on the bottom with screws or they would fasten them from the back sides the chassis slides in and they fastened the chassis like this and then the top portion here of this is usually what holds that you know that the top of the antenna on as you can see this says outside antenna but there is an antenna on the inside of this thing as well I can feel that right now so we remove these four screws and hopefully this will slide out and of course the knobs will be holding this thing in as well so I'll pull this off here like so and let's move these out of the weight turning this back around like so okay now one thing's for sure they're not very tight and that's a nice thing because if you over tighten these things they crack the bakelite case so it's never worth over tightening anything like this a lot of people don't seem to have any feeling when they're tightening these things you're tightening them super tight and then all of a sudden the next thing you know you've got our cracker across the case so very very snug and that's it they don't need to be incredibly tight so this here would look like this should be it and I'm hoping so let's see how usually these will just fall out and lift this up just like so look at that yeah lots of overspray in there do that I can definitely be cleaned up somebody has overtaken this one area that a little bit of crack there I guess that's why this one screws a little longer than the rest of them just move this out of the way area if I damage that case that would be absolutely horrible oh there's even overspray on the inside of the radio look at this looks like primer something's been sprayed on this it's got a nice little red tinge to everything so that'll all have to come off the tubes have even been sprayed yeah you can feel it so yeah okay here's the the moment of truth let's take a look at the speaker look at that it's flawless a little bit of a dent here but nothing's pierced through and it's fine the movement of the speaker is absolutely fine that speaker is an excellent condition one thing that is kind of important to do if you're going to be handling these things a lot is cut out a piece of cardboard and put a piece of cardboard over this so while you're working on the radio you don't accidentally poke your finger through the paper of the speaker it is common that is comics you're not thinking when you're moving this thing around especially when you're changing components and things like that you know and it's all it takes is a slip of a screwdriver or your finger and you've ruined that very nice factory speaker so the antenna looks like it's in nice condition the dial glass looks like it's in very good condition so chances are what they did is they had glass cutter and they cut the corners off like so you can see they've chipped this off so it didn't chip off quite as even as this corner did but it's still in very nice condition it's dirty so I'll have to be very very careful with that one thing that looks really odd about this is that there is no screws holding this thing together so it looks like it's just a clip that's been pushed on the side so I'll have to very carefully here there we go very carefully remove these put them back on and that'll hold the dial glass in place that'll allow me to remove this and I can clean that in fact you want to know something I'll just leave it on there for now it looks like it would very easily come off so I just take this little clip and just slide this right out I'll show you that just remove this like so you know I'm gonna grab this in an area that's I'm not touching any of the lettering and if I pull on this you can see that it'll just come right off you just pull this little clip off myself here and that dial glass comes out like so and you don't want to be extremely careful with this I don't want to damage this at all be very very careful while I'm cleaning this so what I'll do is I'll try a cleaner underneath this area so out of the you know the out of the viewing angle so if any of this paint comes off then you know you got to be very careful and clean around all the numbering and all the lettering so sometimes that can be a very time-consuming process this here as you can see is going to need some some cleaning as well so I'll just move this out of the way over here somewhere extremely safe these things out of here one less thing to break here's another look at the top side of the chassis from a different angle and we can see all the dust and debris crud stuck to the surface so they'll all have to be cleaned off almost even then tuning capacitors on a little bit of an angle here you can see all of the overspray on the side of the chassis and the if' transformer and on the tubes and everything so that'll all have to get clean but that's the easy stuff let's take a look at the underside of the chassis so I'm going to grab the chassis like this being very careful around that speaker so I'll hold this like this I'm gonna grab this here like so and just turn it upside down like that and wow what a mess so obviously there has been some people in here over the years I'll just zoom on in a little bit closer to to what's going on under here so many things where to start I'll start with a line cord so you see the line cord running in right here through a little restraint over here to this lug on the tube socket and as you can see there's copper just kind of dangling right here this almost looks like a cold solder joint onto the side of that lug nice sharp piece of something left over there and this is right up against it now the lugs get hot because the vacuum tubes get extremely hot and serviced and as you can see that little sharp piece is pointing right at that line cord I'll just zoom in here a little bit more sand get a little bit closer to what's going on so I'll just move some of this out of the way look at that piece of leftover wire or something right here see that I'll just point to that with this screwdriver here and this is just right up against it just like that until I bent it out of the way so pretty scary workmanship there this and this and this and this it just doesn't stop okay so I'll back this away just a moment we'll take a little closer look at what's going on in here all right so again where to start so looking at this audio transformer this looks like a replacement I can see the wires are just kind of draped over and tacked into places you look at that screw it's not even tightened down on the bottom the Transformers just kind of hang in here you see that right down in here where my thumb is just kind of hang in there that screws not threaded in at all on this side it is besides loose why not just tighten up the other side kind of strange feel that capacitor is bad so somebody clipped out a bad section just kind of hanging in there and then we have this lead which has been burnt in multiple places melted with a soldering iron tacked in over here this obviously is a replacement capacitor of some sort just laying in here oh look at that it's not even connected on the other side maybe that was supposed to be connected to the chassis so just tucked in there well that's nice so there's that let's move that out of the way what that to poke through the speaker I'll just put this on the backside here let it hang over the backside lots of original capacitors horribly electrically leaky capacitors everywhere about the best capacitor in here is this one this one here will most likely still be good but yeah all the rest of them and aside from the mica here this mica almost likely be okay look at that Wow just an incredible mess now this one here this capacitor here looks like it's been extremely hot and that one ties from a ground portion to the chassis so this is tying from one side of the AC line basically to the chassis and look at how hot it's been it's actually discolored now many times these things are called death cap because these are the ones that short and make the chassis live so there's a lot of things that they did back in the days to keep these chassis 'z away from your fingers things like that you'll notice that the knobs on the front don't have any set screw on them they just have a spline inside them and then if you look at the actual little shaft on the front they have a split inside them so if they get loose you can put a little screwdriver in here and very carefully you give it a bit of a pride now you have to be extremely careful with that because a lot of these things are aluminum and if you do that and even the ones that are brass like this if you give them just a little bit too much they'll break right in here so that has to be done extremely careful and slow and you part these things like so and then they they grip inside a little knob quite a bit nicer you can see how that's nice and tight on there and that holds right to that so another thing to do if you think that you know moving this prying these things apart I should say is going to crack this there's a very easy fix to that as well all you do is you get a piece of scotch tape put a piece of scotch tape over it and then put the knob on and that acts as a shim between the two the sticky side being in of course right and then that acts as a shim and that works it very very well so it's kind of a little trick when you don't want to break these things sometimes those little tricks are you know worth their weight in gold especially if you've ever broken one of these things before and anybody who's ever tried to pry one of these things apart I think is probably broken one of them at some point the aluminum ones are very very you got to be extremely careful with those ones so all these wax capacitors are going to be bad these ones here too this kind of a ceramic shell they're all gonna be bad here somewhere these solar sealed tight capacitors they're sealed tight to keep the leakage in so all of these have got to go it's a mixture of the old round B style resistors in the newer allen-bradley the ones with the squared off ends so there has been quite a few hands inside this thing so where would I start well first of all the very first thing that I would do is take this line cord right here just like so and just do this like that and that'll go in the garbage like so and this will get a brand new line cord and I may as well take this off here as well just get this thing from hang and it'd be interesting to see what's under here let's see what's under this black tape what did they use whoa 220 micro farad at 160 volts this capacitor is known as the cathode bonding wire remover so yeah way out of spec I'll explain more about that in a while a 220 at 160 is way over the top for these things so I'll explain I'll keep this off to the side here so I can tell you what I mean here in just a little bit and I'll explain why putting a capacitor like this in this radio he's a very harmful to the rectifier tube you can see that the factory values right are 50 and 30 okay so we can see here 50 micro farad is the red wire and then 30 micro farad is the blue wire that's the maximum amount of filtering so for you to put those two in parallel you'd get about 80 micro farad maximum all in one capacitor this is 220 not a good thing so whoever installed that obviously didn't know about what happens to the cathode bonding wire in the rectifier tube so the next thing to do is just to go through and test most of all of these resistors it's a real mix of just different types of resistors there's a real thin bodied 470 K resistor right here Roundy very thin bodied much thinner than this one here these are around these right here and then there's a standard allen bradley now you'll notice on these ones here that there is no fourth band which means that these are twenty percent tolerance resistors so it can be within 20 percent of this rating here and this is 3.3 Meg so three three and then five five is five zeroes okay so three three and five zeroes is 3.3 million so yeah there we go that'll be 3.3 Meg ten Meg over here one hundred and fifty ohms here three hundred and thirty K here 470 K here 22 k here 22 K here and this one here looks like the other band is gone off of this one maybe two hundred and twenty ohms most likely on the schematic check this out here in just a little bit see if that's what that is there's only two bands or probably Brown being the third band so 220 ohms ov it imagine alright I'll get some test equipment into the shot here and let's go through and test some of these resistors okay let's test some resistors let's start with this one that looks like it's missing a band either on one end or the other let's find out what this one is 1.8 so that does not add up to anything here so that looks like there might be a Brown band right at the beginning if there is that would be one point two K ohm and that may have moved up to one point eight now since there is no other band on this this would be twenty percent tolerance I'd end up replacing that anyways so yeah I'll have to look into that one here in just a little bit let's take a look at this 3.3 Meg resistor here and get a good connection on that about 4.7 Meg now you're probably saying to yourself while you're testing these resistors in circuit is not not going to affect the reading only in some cases it will in a lot of these older vacuum tube radios there in circuits that are their boiler and high impedance circuitry usually these things are attached in areas that the other end doesn't lead through other components in a lot of solid-state devices there are many other components in the way and there's other things that will really confuse meters so in this old vacuum tube circuitry a lot of the times you can just test resistors in circuit and read them in there now most of the time they read low not high if there's something that's across it and as you can see this is reading high so that would mean that this resistor has moved high so 4.8 Meg that's way out of there that needs to go so here's a 22 K ohm resistor let's see what this one measures 26 say this one measures is another 22 K ohm resistor see what this one measures 22 point three that one's not bad here's a 470 the huge glob of solder running down the side here look at that just a big blob of solder there that's not too bad 472 just about 500 K so there's a decimal place there a point 4 9 9 5 mega ohms so that's just about 500 K still not slowing off so here's a 330 K ohm resistor let's see what this one's at 325 that one's pretty good this is a newer allen-bradley resistor so I kind of imagine that this one has been twisted into place here they've actually taken that and twisted the leads together onto something old and then ran some solder up that Wow this is some pretty scary workmanship in this thing look at that let's twist it up right here why not just D solder that like it look at the size of the blob of solder here this is how they're supposed to look right here's them the lug on the tube socket comes out of this little opening here and then this is the actual thing that crimps the pin of the tube so you can see how far away that is look at this thing it's huge blob of solder run down and here over here so just crazy stuff maybe if I move this I don't want to move this on an angle so that everything is going to end up moving away so all right let's continue testing stuff here so this is 150 ohms it's supposed to be 146 it's not bad 10 Meg this one let's see what this one is nine point six nine point seven so obviously it capacitor in here that's not bad I'm very close to 10 Meg let's see yeah just just some scary stuff across this capacitor here interesting always interesting to see if these things are just dead shorted let's see if this thing is dead shorted probably not let's just find out no still pretty low though Wow lots of work to be done here so what is my first angle well the first thing that I want to do is clean this thing up there's solder blobs and everything just all over the place in here the wiring is just just atrocious the resistors are most likely all going to get changed just because there's not many of them in here you know almost count them on one hand you know 1 2 3 4 five six seven eight maybe you know there's not not a whole lot there might be one hiding somewhere that I'm not seeing me you know it's just almost on one hand you know a lot of the times the the newer versions they had a smaller hybrid like a looking module there are known as couplets and a lot of resistors hidden those things they just had a whole bunch of leads on the bottom like a modern-day device that would just go to all sorts of different places kind of like an icy I've shown this in some of my earlier videos they are the technically are an early integrated type circuit just with capacitors and resistors in the side but these ones here this is old enough that they're all still you know separate on the outside so get rid of all these things and then after that's done we'll clean it up and replace all the capacitors put a new line cord and I'll put a polarized line cord on here and all that kind of stuff so what I'll do is once I have all the resistors and everything all cleaned up in here I'll start explaining a lot about adding a polarized line cord to one of these things and some of the safety things that really need to be known about working on All American five radios there's no transformers in these things so in order to work on this thing you should have a separate transformer which is known as an isolation transformer and I'll talk a little bit about that when I get a lot of this stuff cleaned up and we're a little bit closer to getting this thing running Wow since the underside of this chassis is just in such an incredible mess what I'm gonna do is start desoldering some wires I think I'll remove this audio transformer this is some form of a what looks to be a universal replacement so whether this is even installed correctly is beyond me this is a really good example of why you do not plug one of these radios into the wall to test it out if you find one of these things at a thrift store or a secondhand store online wherever you purchase one of these things there is a really good chance that the bottom portion of the radio that you purchase will look something like this you got to remember this thing is from the 40s and this has been through many many technicians hands and they end up looking like this and really like this is you know it needs to be cleaned up now one of the things that happens when people plug these things into the wall right away when they get them is they burn tubes out so if this filter capacitor here is bad it'll affect a lot of things sometimes depending on the way that the the audio output transformer is wired in they have a tap off the audio output transformer that feeds the high-voltage to other portions of the circuitry you'll burn that tap out and there's a good possibility that that's what's happened here that's why this has a replacement transformer and why they've cut one lead off of this filter capacitor things like that so the the radio itself tells a bit of a story just by the way that it's set now when you plug one of these things in and just say nothing has been done to it it burns out tubes it'll again blow that cathode bonding wire off of the rectifier tube and then immediately you have to go purchase another tube so I'm hoping that the you know the tubes in this thing are okay and look at that here in just a little bit as well so always you know be very very careful these things really need to be serviced before they're ever plugged in because you end up with this kind of stuff all the time and I've come across stuff that's quite a bit worse than this as well so this by no means is the worst I've ever seen but it's this is definitely ranks up there somewhere so what I'll do is I'll start removing this so what we do is I'll just start dissolving some of the wires here so they look like they're pretty loosely tacked on here it says a huge blob of solder on here so I have to melt some of that so that wire is undone let's take a look at this one right over here there's another huge blob of solder on this one hanging out down at the bottom here and again this is again really common a lot of you know tinkerers could have gotten in here and experimented with this and stuff over time again you know that these things they tell quite a story you know just over time they've been you know in through so many people's hands right this lug here is pretty loose as well they're usually knocked out loose so there might actually be something broken under there if there is I'll put a different type of standoff in here to support the wires later on again I'm not too worried about these wires right now I'll figure this all out in just a little bit as you can see everything's just tacked on things are just falling off a huge blob of solder down here look at this huge molten ball of solder so what I'll do is I'll get my vacuum tool in here have a vacuum desoldering tool and I'll just get that out of there and it sounds like it's actually plugged my soldiering tool I can see stuff starting to poke out of there let's see if it is plugged that was a lot of solder that this thing inhaled yeah I think that's just uh I think that's my issue not the actual solder because I haven't cleaned out this cap so I'll here in just a little while so I'll probably have to clean that out so there's one got rid of all of that solder look at how much that took out of there I think this thing is full so let's see yeah look at that it's pretty full so I need to go about cleaning this out put that into my little bin here in just a moment a little bit of room in there when I poke the little cleaning tool in there moved it some of it out of the way so I can vacuum up another huge solder blob look at this look at the size of that solder blob they're all over the place listen here I'll probably do it in get that one out of the way just things like dining and have to go through and clean all this kind of stuff up you know this is a well what a mess okay so back to this so there's these wires here out of the way and there's multiple taps on this I'll read the legend on the top here and explain what the legend is this is common for replacement audio transformers and so I'll help you figure out how to replace an audio transformer like this in one of your units many of these things come Universal now so you can put them into many different applications on this side here it looks like somebody's just tied up the speaker leads on to the old ones so this looks like the old speaker leads and they've just kind of twisted what's left over together here it's just a mass so I'm not even to bother desoldering these things what I'm gonna do is just clip them out like so and I'll get in here with my screwdriver and just remove this transformer shouldn't be too hard because one of the screws isn't even in there look at that just barely in there so get this thing out of the way down out of here and I can even test this here in just a little bit so the legend is really nice on this and again I'll explain a little bit about this here in just a little bit looks like a nice little audio transformer so just getting that thing out of the way cleans things up big solder blobs on the chassis probably end up heating those things up with my solder and gun in order to heat things up like this on a chassis these are it takes a lot of heat to do this and I have a video that takes a while or solder and gun it's this one actually right here it's sitting off to the side and you put a copper tip on it like so and that creates heat a lot of heat really fast and that allows you to melt these solder blobs here and get them off the chassis to clean things up as well at this point I've replaced all the resistors and all the capacitors on this side of the chassis with brand new components before I installed each component I tested every single individual part to make sure that it's as close to its value as possible again we want to see how this radio receiver performed when it rolled off the factory production line back in the 1940s so by doing this it's just going to get us that much closer to that type of performance before I reinstall all the vacuum tubes I'm going to test each one for emission if any of the vacuum tubes are weak I will replace them with a brand new device the last thing that we would want at this point is something as simple as a vacuum tube hampering the performance of this radio receiver you'll notice on this side of the chassis I really haven't done anything to the wiring at this point and that's because there's a couple of topics that I really need to cover and one of them involves safety around all american 5 and all american 6 receivers so this is the all american 5 version so first of all the line cord that was issued with this radio receiver is not polarized so you can plug it into the wall anyway so this is the factory plug and you'll notice that both of the spades are the same size so you can plug it into the wall this way or you can plug it into the wall this way and that gives us a 50/50 chance of bringing the chassis of this radio receiver close to the hot side and that isn't a safe thing we need to make sure that the chassis of the radio receiver is firmly fixed to the neutral side of the line cord now when the line cord is replaced on this radio receiver it will be replaced with a polarized line cord so one of the spades will be larger on the plug than the other so we'll only plug into the wall one way we can traverse it usually the larger Spade is the neutral side in that neutral side needs to be as close to this chassis as possible now in a lot of these radio receivers they put the switch in the opposite side so we need to move this switch over to the other side so these radio receivers do not have a transformer in them this is a transformer 'less set which means that this can run off of 115 volts AC or DC so if you had a whole bunch of storage batteries and you put them in series you could run this radio off of just a pure DC source now if we look at this we need to keep the neutral line as close to the chassis as possible and that means that this side needs to be neutral this is a ground symbol and this is a chassis symbol so that raike looking symbol there means the metal case of this radio receiver this here this wire and this portion of the potentiometer all of this this is all this ground symbol right here so well once your grounds are interconnecting through here they tie at this point right here and then this is the chassis now you'll notice between the ground symbol and the chassis symbol we have a point 0 5 micro farad capacitor rated at 200 volts and a 220 K bleeder resistor across that capacitor so that's in parallel with that cap that's this capacitor right here and hiding just below this other one here is that resistor okay 220k this capacitor here is often referred to as the death capacitor that's some pretty strong words for a capacitor but what happens with these capacitors is they often short so if this capacitor shorts and becomes a jumper it's gonna connect this here this side to the chassis so if it did connect this side to the chassis and we still had the non polarized line cord on here and we had it plugged in remember we have that 50-50 chance with the other with the other line cord right that would make the chassis of this attached directly to the hot side which is extremely dangerous so we need to eliminate that chance so by putting a polarized line cord on here we have to move this switch over to the hot line so the neutral line is always firmly affixed to the ground over here and then of course we have the capacitor running across here to this we have to replace this with the appropriate safety cap - I'll talk about that in a moment so I need to move the switch over so that means that what I'm gonna have to do is remove these wires off of here now there are a bunch of grounds here there's a ground running from here over to the heaters and then there's a jumper lead right here so I don't know if you can see that I'll just get this closer into the shot here and I'll zoom on in so you can see right here there's a jumper that runs from the bottom portion of this switch down here right down here up to here so basically this ground and this ground are tied together right worth you know the line comes in as a switched right here now the reason that they have two lines and they just didn't run it up to here and then run this over to the other side here and then just bridge this over to this side the reason that we have two grounds is because one of them carries a lot of current and if we were to have the current going through this one here you'll see that this is on the potentiometer right here right so see the potentiometer right here it's on here if we were to feed the current through this line right here what would happen is we would get a lot of hum in the audio because this is attached right to the ground side of this resistor which ties to the grid of this vacuum tube and that's a very sensitive part of the tube so they need to run two separate grounds one that runs to the filament because there's gonna be current on this line and this line here really doesn't have any current on it and it's just gonna keep that free of hum so something to keep in mind if you're ever replacing or you know modifying a chassis like this you want to make sure if you see two grounds to definitely keep them separate and keep it as close to the you know tying to say the neutral as possible but again we have to get this out of the switch line because we need to use this switch now for the hot side okay so the way that I'm going to fix this problem here is I'm going to install a standoff right here on the chassis you know I have to be careful in this chassis because you can see there's a cutout here and there's a piece of the case like the actual case of the radio and extrusion that runs through here and then the screw goes through a hole on the backside of the chassis here so through here there's going to be an extrusion like this so I need to make sure that the standoff isn't in the way of that extrusion so it'll be closer to the potentiometer the neutral line will run over to that standoff I'll run a line from here down to the neutral I'll replace this wire here because it's going to be too short I'll run it over here to that neutral as well and then I'll completely remove this from the switch so I'll remove this one little neutral jumper debt that runs through here get this out of the way I'll run the remove this neutral jumper and that'll free up the switch I'll also remove this resistor off here as well so that these two terminals are completely clean then what I'll do is I'll run the hot line up to here and then the hot line from the bottom portion of the switch will run back to here and to this point right here and that'll make this a lot safer now this capacitor here needs to be replaced so this one here this one here is known as that death cap this capacitor has to be replaced with the appropriate safety capacitor I'm going to replace this capacitor with an x1 y2 rated capacitor which is like this one right here this have all sorts of safety features built right into these things these are designed not to fail in a short condition okay so these are the modern replacement for this cap this always has to be addressed in every single radio receiver like this because chances are it's gonna have a waxy like this and these things are in some form of decay or disrepair and if this thing shorts its you know and you have that say you had a non polarized line cord on this it would make this thing all that much more dangerous I'm also going to test the audio transformer as well because this is a replacement audio transformer and there's something that really isn't talked about these audio transformers here you'll see how we have a tap that's on this audio transformer that's on the other side of where the B+ goes in so you see how we have the B+ running to this tap but then out here we have a tap coming off the transformer and that powers the rest of the radio I'm going to talk a little bit about why they're running this tap off the transformer to the rest of the radio here in just a moment when we test the transformer as well since this radio receiver has been so heavily tampered with over time we should really test the replacement audio output transformer as well so somewhere down the line the original audio transformer had burnt out in this was the replacement so before I go about reinstalling this whole thing and connecting up all the wiring I want to make sure that this thing is okay so I'll show you how I do that and I'll also show you a few things that catch a few technicians as well I'll also explain a little bit about this transformer topology here this is a little bit of an odd wiring setup I'll explain that here in just a moment so we can see on the transformer here we have red is B plus in blue is 3000 ohms we have blue and white which is a three percent tap and then we have red and yellow which is a six percent tap and then the secondary is 3.2 ohms right here that would be the secondary so we don't really have to worry about this this is the side that usually goes wrong in these little audio output transformers it's rated at five watts - not too bad so it says red B+ and blue 3000 ohms so this would be the B+ line right here so this would be the red line running up to this tap right here and then the blue tap would run over here to the plate of the 50 l6 tube now you see on the transformer here it says 3000 ohms so when we measure this from red to blue okay so I'll just touch this to here into here you can see it says 185 ohms it doesn't say 3000 ohms well why is that a lot of people would think that no maybe the transformer has short it turns or something like that right this is an impedance rating this measures DC resistance so what's happening here is this is an AC resistance measurement these meters only measure DC resistance that's why we're seeing that we need to have a special meter in order to see that 3000 ohms and I'll show you that here in just a little bit so don't get caught by that if you ever see you know the an impedance rating on a transformer like that and you measure and you find that it's a little bit low measuring with a meter like this that's quite normal again you're measuring DC resistance now some transformer manufacturers are nice enough to actually put the DC resistance rating rate on the transformer as well these guys they didn't do that they just put 3000 ohms here now you can see here it says blue - white is a 3% tap and then it says here red and yellow is a 6% tap now what we don't know about is whether these taps are on this side of the B+ or whether they're on this side here now you can see in this transformer topology it's kind of a little bit odd you see we have the B+ line running into this tap up here and then we have a winding further out that runs out and they power the rest of the radio off of that winding there's even a 20 micro farad capacitor there well why are they doing that some people might think well there's some form of feedback or something like that not at all the reason that they're doing this is to eliminate hum so this is a hum reduction technique that they used to use way back when so some radios had humbucking coils on the actual speaker itself or on the speaker side alright but this is just another hum reduction topology just to get rid of hum so what we want to do is we want to find whether this transformer is a very good replacement whether they actually research this and found a transformer with the taps on this side or whether they've put taps on the other side as well and we're along the winding these taps are so we can very easily do that with just a DC resistance reading so we know that from the red line here this would be the red line to the blue line we had a hundred and eighty five ohms right so it's a hundred and eighty five ohms from here to here so if this tap so if say the blue and white tap was on this side from this portion of the winding it would be lower so it might be 180 or 170 ohms from this portion from the blue wire if it's a hundred and ninety ohms maybe 200 ohms it's going to be on the other side of the red wire so let me give you an example here okay so we know already that we have one hundred and eighty five ohms or something like that okay one hundred and eighty five ohms from here to here so I want to measure from here to the blue and white tap because that's three percent so that's going to be you know the first one that we're going to try so we had a hundred and eighty five ohms from here to here so let's test to this one here a hundred and ninety two it's further away than this tap so we know that we're going this way so this output transformer actually has this winding inside it and then this is a six percent tap so this here should be really high this one should be really far away from the B+ side here yeah look at that 198 so technically these two should be very close together they should be you know in the low owns apart from each other and there they are 6.8 ohms so this is 6.8 ohms this way on the winding and then the other tap was let's see how many ohms would that be away from the red B plus lead 12.9 so 13 ohms away so we have 2 taps we have a tap that's this one here we could call that you know the this wire here or we could call it this wire here now I don't know how many ohms the actual resistance is the DC resistance is from the b-plus line on the original transformer because that kind of stuff just isn't talked about now here's the thing I'll get this out of the way these transformers can very easily be replaced with just a standard four wire type audio output transformer so we have the primary side will have a red and blue wire on the primary side and then whatever colors they choose for the secondary side would be absolutely fine the reason that we can use just a standard two wire type transformer to wire primary type transformer nowadays is because we have much better capacitors and finding values higher than 40 micro farad and 20 are very very common nowadays and you know if one was worried about damaging the cathode on the vacuum tube so if you're worried about you know the cathode bonding wire and the vacuum tube you could very easily put a dropping resistor to the rest of the radio receiver and it just put another capacitor there and you eliminate hum that way so way back when when these radio receivers were put out capacitors with you know high micro farad values weren't really all that incredibly common and the factory filter capacitors were very expensive back in the day so you know the factory capacitors and the audio output transformers were - very expensive components in this radio receiver nowadays capacitors you know incredibly well they're cheap nowadays and you can getting extremely high quality capacitors for very reasonable prices so there are lots of ways around this but it is nice to know that this transformer here has these taps on this side so what I'll do is I'll try them the the blue and white tap here and then I'll try the the red and yellow tap here and I'll see which one works better with the receiver I imagine I'll probably end up just using the one closest to this as I'm you know putting better capacitors in here as well so now what we want to do is we want to actually see whether this transformer is what it says it is we want to see whether it's 3000 ohms so I'll hook this up to a different meter and we'll check out the actual impedance of this transformer and I'll show you how not having a load on a transformer really affects the impedance on the primary side let's test the impedance of this audio output transformer using the gener at sixteen eighty nine M so what I want to do is I want to attach the blue and red leads so we can see the red is the B+ and the blue runs to the plate of the vacuum tube so these are the leads of interest to get three thousand ohms okay so what we'll do is I'll attach that up right now balloon attached and readily detached so you can see we have nine point one K ohms when we're supposed to have three thousand ohms why is that well we don't have any load attached to the secondary so what I'll do is I'll attach a 3.3 ohm resistor up just because I have one handy so for 3.2 ohms we should roughly get three thousand ohms on the primary okay so I'll just attach that right now and the other side is attached and look at that we now have three K ohms with the appropriate load attached so the a 3.31 resistor across the second area of this transformer now watch what happens if I remove one jumper clip you can see how the impedance goes high and that's why it's so incredibly important in a vacuum tube audio amplifier and even some solid-state amplifiers that have transformers to have a load attached to them if there's any type of amplitude happening so usually for testing purposes with tube audio amplifiers you know if you keep the output very very low it's usually okay to run them without a load but once you start turning that volume control up or once you start turning your signal generator amplitude up you definitely need a load or you'll damage your audio amplifier I have this portion of the chassis all cleaned out and I'm ready to start rebuilding in this section I've also installed this little stand off over here from the neutral wire so that's all ready to go but before I start rebuilding that section and putting a line cord on this I'd like to clean the chassis up first on the upper side so when you're cleaning things up and you have a line cord dangling around it's kind of a pain it's nice to have this thing kind of stand alone right now so there's nothing really hanging off this so what I'm going to do is I'm going to D solder these two wires here and I'll die solder these two wires and that'll allow me to remove the back while this is off I'll clean this up and replace this capacitor here as well I'll replace this capacitor with a safety capacitor one of those disk style capacitors over here I've disconnected the speaker leads and I've also removed the dial lamp so I'm going to remove the speaker that's very easy there's only two screws on the bottom side of the chassis so with the speaker removed the dial lamp removed and the back side remove it'll allow me to get to the chassis all that much easier without me bumping into things I'm going to have to use an aggressive chemical to get this overspray off and I really don't want to be taking that aggressive chemical and rubbing against these wires because there's a varnish on these wires so I'm gonna most likely be using lacquer thinner to take this off so I'll use a a rag in some lacquer thinner and this will be done outdoors so lots of ventilation so if you're ever gonna use a chemical like lacquer thinner you need to read the safety precautions because that stuff is pretty toxic you got to be very very careful with that and the fumes are very bad as well so things to keep in mind if you're gonna use an aggressive chemical like that so what I'm going to do now again is just remove the speaker remove the back I'll get the entire top side of the chassis cleaned up and then I'll start rebuilding the bottom you'll also notice that the tuning capacitor here is on a bit of an angle and that's just because the tension of the dial string over time because of this spring here is kind of pulled this whole mechanism the tuning capacitor and this bracket over a little bit so basically it's kind of put a little bit of pressure on the rubber grommets on the bottom now here's the thing the rubber grommets are still fine they're in really nice condition and they're nice and soft still this rubber is extremely soft pretty much like the day it came up from the factory that is you know really soft so no problems with that whatsoever one thing to always make sure if you're gonna leave the original rubber grommets in if you suspect that they're OK's you want to make sure that there is a space between this bracket and this chassis these are two separate grounds this is chassis ground and this bracket is RF ground they cannot touch each other at this point and that's the reason that there's these rubber grommets holding this assembly away from the chassis so something to always keep in mind if you're ever working on a receiver and you don't replace these grommets and this bracket touches the chassis it'll create all sorts of problems in the oscillator section things like that the chassis cleaned up very nicely all the overspray is now gone you're rid of that thick layer of dust and all the grease and debris and everything so before this is all finished I'll put a spot of oil in here a little spot of oil right down in there so let's grab something to point with here put a little spot of oil right down in there and I'll put some oil in this front bearing you can see all the little balls in the ball bearing there some oil in there as well and then on the face of the unit I'll also put some oil in here put some oil in here I'll put some oil right down in here because this the tuning shaft right here goes into that little bushing put some oil right there and I'll also put just a little drop of oil right there just to make sure everything moves nice and smooth this cleaned up very nice as well is just some grease on there from me moving this thing around this cleaned up very well and the glass cleaned up too now I tried in a very inconspicuous area and I just used water I used nothing else and where are the little lines were in that felt that protects the glass with the clips I tried some water in that area and the paint on the back side of that dial is really tough so there's no problems there so I put some on an actual shop towel I have them here one of those blue shop towels at any rate we just put some water on it I very carefully worked at the backside of the glass and that turned out very very nice so we'll take a look at that here when we do the alignment after this is all reassembled the underside of the chassis is now complete so pretty much at this point I could test the tubes put the tubes in and try it out it's that close audio transformers reinstalled I tap the chassis to 6:32 and use some nice stainless 632 screws to hold the transformer in terminal ties trip over here is installed with the two new filter capacitors safety capacitor is mounted here with the 220 K ohm resistor there that all worked out very well the new line cord is installed you can see there's a protective coating over the line cord where it goes under the cable restraint and then the cable comes over here runs over to here so this is the neutral connection and this is the hot connection through the switch and back over here to this tube socket see that right there so everything worked out very well I've also attached one of the speaker output leads right to the chassis so you can see this little wire here from the audio output transformer secondary runs rate to ground on chassis and I'm running this lead here up to the top side the reason I can do that is the factory speaker here has one of the connections grounded right to the shell of the speaker and this is tied to the chassis so I don't need to run two wires up here to the speaker that's the reason they do that so you can cut down on wiring and which is kind of nice because this little hole in the chassis down here is kind of tight with all these wires in it so it worked out really nice eliminating one wire so the only wire running up here is the hot lead for the speaker worked out very well new safety capacitor installed for the external antenna connection everything is cleaned up I haven't lubricated anything yet I'll end up doing that so really all I need to do now is test the tubes populate this with tubes and it's ready for an alignment let's test the 50 l6 vacuum tube first as you can see the overspray is still on it I haven't cleaned the tube yet because if the tube is bad what's the point right so before I plug this tube into the tester I need to set the tester up if you ever plug a tube into a vacuum tube tester before making all the adjustments you can damage the tube or even the tester so I have this set to 50 l6 so this is just a roller chart so you can roll this and find out where everything is lots of tubes on here so I have a B C and D here so I need to set a to one so this is a up here so I have to set that to the number one it says B you set to fourteen pointing to fourteen right here C points to number four C number four and then D is number two so this is D here I have to move the lever up number two to D here now I can plug the tube in what I have to do first after the tube is plugged in and warmed up is readjust the line you'll see this will move off of the little line adjustment when I plug the tube in because the tube loads of the circuit see that and as it warms up it'll creep back up and then once the tube is warmed up and it's into a mission then I'll readjust the line here then what I want to do is move every one of these levers to the F position first if this neon bulb stays on it the tube has a short is just going to be discarded but if it flashes that's absolutely fine so all of these levers with the exception of number seven number seven will shut the filament off you can see here number seven I'll demonstrate that here in just a moment so I'll move this up to the little arrow right about there so I'm going to move every lever just to the F position in back again and we should see this flicker if it stays on the tube gets discarded that means that there's an internal short somewhere you can see the filament going out on the vacuum tube that's number seven so no problems there so the next step is to put f two three four and five so this is f right here so I have to go three four and five now I'm ready to test the tube just readjust the line make sure it's spot-on that little arrow there and here we go no problems it's in the good area no problems whatsoever the 50l six is good now all the rest of the tubes in the radial I have to do this too and some of these tubes have three sections inside them so that's three complete separate tests and moving all these levers so it is pretty time-consuming so I'll do that off of camera and if there's any weak tubes I'll replace them and get them all installed so we can do an alignment I've tested all the tubes in this radio receiver and there was only one weak tube and that's the twelve sq7 this tube plugs into this socket right here so I've replaced this tube with the one that you see right here this is an audio amplifier and a detector so if this tube is weak that would affect the way this radio detects and amplifies the signal so we definitely wouldn't want that at this point I'm ready to try out the radio receiver and see if it comes to life now if you're following along and you're repairing a radio receiver like this you're definitely doing so at your own risk you need an isolation transformer whenever you're working on anything like this and it's extremely important to have an isolation transformer especially with test gear attaching to the chassis and things like that as well so the isolation transformer I have is current limited and it also has a very act on it so I can bring the current up and bring the voltage up here slowly so be very very careful if you're working on any type of an all-american five or All American six transformerless receiver if you haven't heard of what an isolation transformer is I strongly suggest that you look into it okay I'm gonna turn this thing on and I'll bring it up slow someone or to my variac right down turn on the supply turn it to about 30 volts or so and I'll turn this on so now normally when you turn an all-american five our all-american six radio receiver on the dial amp will get bright and then go down that's absolutely normal this light is powered off of a tap on the filament of this 3505 rectifier there we go so that's normal and that is a good sign so I'll just let everything come up nice and slow here you see the cathodes are glowing in some of the tubes I'll bring it up just a little bit more bring it up to about 75 volts and at this point I should probably start to hear some noise in the speaker if everything is working okay very faintly at any rate turn this out and it's coming to life that's a good sign so I'll turn this down I'll bring this up to full line voltage here that's up to full line right there give it a bit of volume now there's no alignment no RF alignment and Wi-Fi linemen no anything so let's just see how this receives I'll just quickly coast through the band here not bad [Music] so it's definitely alive it's definitely working so the next step is to do an if' alignment and that's aligning the little adjustments inside this can here and then after that's done I'll end up doing an RF alignment so that means that I have to put the dial glass back on and I'll have to line up the pointer first of all because I'm not sure if this is even on each side let's see it might be pretty close we'll find out if it's off the needle here has some form of tape that they've stuck on the string and that's gonna be very difficult to move so I might just loosen up these set screws right here and allow this just to slip on that shaft there and I can adjust it that way as well so in a way that's kind of cheating I don't have to move the the needle on the string here which is kind of nice so this has been stuck in this piece of taper for who knows how many years and that would be very difficult to get that moving on the string I'm now ready to perform an if' alignment on this small radio receiver using this vacuum tube voltmeter as an indicator and a signal generator that's feeding a signal into the if' chain so I can adjust both of these if' transformers successfully now before any alignment is begun on a small radio receiver like this especially anything with vacuum tubes in it it's a really good idea to let the receiver or device under test warm up for about 15 minutes or so that's a good number for an All American five or All American six receiver now that'll depend on the type of receiver that's being aligned some receivers in the actual alignment instructions call for 45 minutes - over an hour of warmup time to let everything stabilize it's also a good idea if you're using a vacuum tube voltmeter to let it warm up and stabilize as well because it has vacuum tubes in it so I'll explain exactly what I'm doing here in the top of both of these if' transformers there's two adjustments there's two capacitors in each if' transformer and I have to tune them all for a peak signal I want to get the maximum amount of signal going through the if' Jane so from my signal generator going through the if' Jane and I'm going to be reading that signal at the speaker because as I tuned this and more signal gets through it's just going to get louder and this will give me a visual indication of that so what's happening here is I have just enough signal from my signal generator going into the radio receiver here just to put a little bit of a tone there I don't want to overload the front end or cause any AVC action to happen I just want just enough signal there so when I pick things up it'll get louder and louder and louder and then once it gets loud enough or too loud I'll turn the signal generator back down again and repeat everything in order to get the maximum sensitivity out of the if' chain in this radio receiver so there's a 455 kilohertz signal going into this little device and going to this red alligator clip right here and there's a 1,000 cycle tone on that signal modulated to 50% so that 1000 cycle tone is what we'll be hearing in that speaker now a lot of the times if it gets too loud what I'll do is I'll disconnect the speaker and actually put a dummy load in there so I'll use a say a 3.31 resistor like we use to test the audio transformer that way I don't have to listen to it while I'm aligning it but I'm going to let the tone happen just so that you can hear and see what's going on to give you a better idea of what what's actually happening in this alignment procedure so that red alligator clip right there is attached to pin number 5 of this 12 sa-7 that's the control grid of the mixer tube right here okay so that red alligator is just clipped right here and then the black lead here which is just common is clipped to the chassis the common lead of my vacuum tube voltmeter is also clipped to the chassis and I'm going to clip this alligator clip which is attached to the Pearl break to the speaker all right so it's just going to be looking at the the actual speaker that's what we're going to be looking at right here now here's another thing to always keep in mind whenever you're aligning a receiver like this this thing right here is attached to an isolation transformer and a current limited variac supply and that's absolutely crucial when any work or any servicing is done on a receiver like this so again if you're following you're doing so at your own risk be very very careful if you if you didn't use an isolation transformer extremely bad things would happen what usually ends up happening is you blow the lead off the test clips it's things like that it's very very dangerous so depending on the application an isolation transformer especially for this is necessary definitely a necessary thing to have all right so you can hear a tone so I have my signal generator putting out just enough signal to get a tone in there I have to attach this up to the speaker now so that I can get a reading and I'm gonna take my insulated screwdriver and adjust these tremor capacitors inside this if' transformer now one other thing that I should mention and I've mentioned this before in other videos is inside these if' transformers just gonna put this schematic off to the side here inside these I have transformers those two capacitors in many different types of radio receivers are attached to the high-voltage they've actually attached those caps to the high voltage supply so if you go in there with a non insulated screwdriver this one is double insulated it's plastic and I've insulated it again with tape just to be safe so if you were to go in there with a regular screwdriver and if you touch the the top of the trimmer capacitor and you touch the case of this if' transformer you short out the power supply and a lot of the times you damage things so that fools a lot of text and that causes a lot of problems with if' transformers as well so something to always keep in mind whenever you're aligning anything with if' transformers and recessed tremor capacitors much of the time those recessed capacitors are attached directly to high voltage in the radio so there's a little tip a very important tip so what I'm gonna do now is I'm just gonna work my way through these capacitors and I'm gonna be looking for a peak okay so I'll turn this up until I get just a bit of a tone okay and I'll go into this one first and I'll give this a bit of a twist now you can see that I gained some sensitivity there right so all this I'll just put this up here like so I'll use this to sturdy the chassis so you can see how much that came up so I'll go down to the next one here so you can see this is way out of alignment again we're just using this meter to peek doesn't matter where the needle sits as long as we're getting a peek if you pass it just go back and do it again there it is I'll go over to this one here [Laughter] steady this over here look at that he stuff set screws are very very stiff so I have to turn that down now you can see how loud that is so now I'm going to turn the amplitude of the signal generator way down okay so I turned that way down again so I can turn this up just a little bit again a lot of the times I would do this with an actual dummy load so I wouldn't have to listen to this but this gives you an idea of how much this is coming up with that actual sound so I'll go over to this one here so you can see they're all way out of adjustment so I'll go back up to this one here again and I'll go back to the front one here again again I'm just looking for a peek that's all I'm doing and you get the idea so I'll just go back and forth I'll reduce the signal on the signal generator one more time and I'll just go through here and a line that this thing is gonna be a lot more sensitive than it was when we first tried this thing out just a few moments ago so these I F transformers were way out of alignment the radio is off and I'm going to reinstall the dial glass and this is actually very easy to put back on so I just want to make sure that there are no fingerprints on this so I'll just wipe off the bottom portion here it's looking pretty good I don't see any fingerprints on that so now this goes on with just clips so there's a piece of felt that protects the glass from being damaged a piece of felt that goes on this side so I'll just pinch that felt here like this and I'll grab the felt from the other side and that goes on here like this now the person that had put the dial glass in the last time didn't put the felt in the straight so the felt has been on here for a long time crooked and now it's taken that form so this little clip here has a little bit of a bow to one side that goes to the back side so you just press on a little clip just like that and then the same for the other side this one here with a little bow goes towards the back side I'll just make sure that the felt is nice and even this is the one that was put on incorrectly so there it is just hold that like this it's wanting to try and do it again it's just it's holding that form I guess who knows how many years it's been in there like that so hold that and then I'll just put this on here like this and just give it a bit of a push and it should just slide on ever so gentle and that's it that's it for the dial glass now you want to make sure that it's roughly even on each side it's lookin pretty close and I don't think I would want to force that at all now I'm gonna probably go in here with a q-tip later or something like that make sure all that castas out of here because it's going to accumulate dust throughout this tuning procedure now this dial pointer should align up with that last little notch and when I go over to this side it should line up with that notch now you can see it's over this way and it doesn't go far enough over this way so I want it to be even see that so what I'm going to do here is just let this down for a moment and I'm going to get the dial light out of the way again the power is removed at this point let's get this off of here just put that over there there's a bunch of set screws down here I'm going to loosen one of those set screws off so I'll just take a look over here so remove or loosen off this one right here first of all just so I can see that loosen this one off like this and now when I go the other way I'll also be able to loosen this one off so this is the one that I'm gonna most likely be tightening because I have a clear shot at this screw so now what I want to do is I want to move that dial pointer I want to make sure that the capacitor is fully meshed and I want to move that dial pointer right over onto that line like that and then now I'll go back here bend this forward so I can see this tighten that one screw up I won't tighten the other one up yet I'll just make sure everything's even so it's right on that line and then that's actually a little bit over and then this is over this way now so now what happens with these a lot of the times when you're tightening them when you tighten the screw it actually causes the shaft to turn a little bit so if that happens you fiddle with it just a little bit more make sure that it's all good let's make sure the capacitor is fully gained sometimes can take a couple of times to get it right and I think I might have it this time there it is okay so you can see if you look at it straight on okay it looks like it's off just a little bit there but look at it straight on and then over here it's the same thing so you can see that was a little bit time-consuming so now what I'm going to do is since there's two set screws you can see that there's two set screws on here I'll tighten up the other one that's loose now and that should lock that in place and then we can go about starting the oscillator alignment so it'll be the next thing that we align is we want to make the dial accurate to what it says so say we're tuned to 600 a.m. we want 600 a.m. to be here right so if it's not say 600 a.m. is here we need to adjust this little screw up here to make that correct I believe it's actually adjusted at 1500 on this radio receiver 1500 I believe we right about here so I'm now ready to perform an oscillator and antenna alignment on this radio receiver so that's the adjustment of this capacitor here this is the oscillator section and this is the antenna section so by adjusting these two capacitors it's really the last two steps that need to be done in making this receiver perform the way it's supposed to so first of all this here sets the dial tracking so when I say dial tracking on this piece of coax here on in this little box right now I've got a 1.5 megahertz signal or 1500 kilohertz however you want to call that modulated by a 1000 cycle tone at 50 percent modulation so there's just a signal sitting here at 1500 kilohertz so what I'm going to do is lift this radio up and I want to make sure that when this is pointed at 1500 this is 1500 right here it's right on that little line so if I move that you'll see that a line so that rate there is pretty close to 1500 it's a little bit off because of the way the radio is sitting but it's very close so I want to make sure that when I turn the volume up I hear a tone if I don't hear the tone I need to search around the Ben and in find where it is to make sure that I'm actually you know listening for something not supposed to be there so what I'll do is I'll turn the volume up and I just hear some radio stations but I don't hear the tone so what I'm going to do now is rotate this and there it is now you see how that is not right on where it should be this is the 1500 kilohertz mark right here so it should be receiving that right about here so now what I need to do is put the dial pointer right here where it's sitting right now and I need to turn this little adjustment right here until I hear that tone when I hear that tone right here I've done my dial alignment just that easy so what I'll do here is I'll put this in here like so turn up the volume and I'll just give this a twist [Music] right about there and that's it for the oscillator alignment now we really don't have any choice if the dial accuracy is off on this radio receiver because that's the only adjustment to adjust the dial tracking so it's always interesting to see how close it is so right here is 900 kilohertz let's see how close that is I'll set my signal generator to 900 kill Urtz okay I'll just roll down here let's see if we can hear it hey look at that it's right there so that's looking really really good a lot of the times what really affects this is the cue of the coil changes so this right here is the oscillator coil and it's very sensitive to change so to give you an example of how sensitive this is all right so what I'll do is I'll just I'll prop this up like so just put a screwdriver under here or something like that and I'll do this to that tone now watch when I bring my finger close to this coil it goes right off frequency so any shift in the way that that coil form has been made so if the radio has been wet over time and either that or the coil form has shrunk or there's you know been any type of an issue the rate has been overheated or left in a really hot attic for many years sometimes those coils they deform and then the the dial tracking is really hard to get right on spot-on but this has been you know kept in a relatively nice-looking out miss for you can see the chassis is entrusted or anything like that and you know so that's most likely the reason that this lines up so incredibly nice so now back up to 1500 again so I'll just move this over here so the next thing that I need to adjust is this one in the back that one adjusts the sensitivity of the receiver at 1500 so I'll move this right back on to 1500 put this back up to 1.5 megahertz okay and I'll tune this there it is now what I'm going to do is adjust this for maximum sensitivity so I just want this to get as loud as it possibly can there's something stuck on this here like a piece of solder or something hmm that's interesting that's a piece of fuzz alright so here we go again you can hear here how it's getting nice and quiet now right right there is at maximum sensitivity and that's it the alignment is done the radio receiver is now completely reassembled so let's see how well this little radio performs after this entire restoration process so what I'll do is I'll scan through the band and we'll see how many radio stations we can hear on this little radio receiver so I'll turn up the volume here they care about the safety of the church that economy is really fun and motel 6 dark the elimination just the fourth different kids plane repairs on Saturday stick together they vote together do something about it so your [ __ ] thankfully put on the old CD the hammer that's good name by Adam says some Cooper across the channel coffee for a limited time he's one of the best I've seen Nathalie ray please ugh I would say that receives incredibly there are radio stations all over the band and it sounds really good so restoration successful what a nice little radio receiver this thing is and now for the answer to the last videos trivia question I try to include a little bit of electronic trivia in each video so the question was what is this device and in a moment I'll tell you what it is so I'll take a quick look at this again the three leads on the bottom kind of give it away for those of you that are familiar with this series okay if you want to guess what this is pause the video now because I'm about to tell you the answer this is an ion 13 indicator tube and these things are used as spectral displays in equalizers and people are using these things in newer projects for thermometers and things like that indicate temperature all sorts of really neat displays it kind of looks like a bar graph display when you're using this thing in service so it's a gas-filled tube and they have quite the following Mountain so there's a lot of people building little projects with these tubes right here so I plan on building something with this down the road in fact on patreon I just designed a high voltage power supply that runs off of batteries that will end up operating something like this or a whole bunch of these things so this would look really good as you know a display for an equaliser or some sort of spectral display having a whole bunch of these things moving to different frequencies and all that or even just up you know a sound meter or something like that give you an idea of the level of sound around you things like that very neat little device so that's what this is so now for the next videos trivia question now I'm not going to turn this around because there's some writing on the other side that'll give it away but what is this device and where would something like this be used so there it is the next videos trivia question thanks for stopping by the lab today I hope you enjoyed this video involving the majestic radio if you are enjoying my videos you can let me know by giving me a big thumbs up and hang around there'll be more videos like this coming in the near future we'll be taking a look at vacuum tube and solid-state electronics alike so if you haven't subscribed now would be a good time to do that as well if you want to be notified immediately when I post a new video don't forget to tap the bell symbol as well if you're interested in taking your electronics knowledge to the next level and learning electronics in a very different and very effective way you're gonna want to check out my ongoing electronics course on patreon there's many topics up there and many videos as well I'm also sharing many of my circuit designs and projects up there for everyone to build so definitely check it out I'll put the link just below the description and I'll also pin the link at the top of the comments section alright until next time take care bye for now you

Channel: Mr Carlson's Lab

Views: 142,463

Rating: 4.929812 out of 5

Keywords: Majestic Radio, radio restoration, receiver restoration, tube radio restoration, fix electronics, repair electronics, restore electronics, learn electronics fast, radio alignment, IF alignment, RF alignment, oscillator alignment, antenna alignment, VTVM alignment, test equipment, electronic lab, majestic radio model 5A410

Id: TXKfg5Rdi3U

Length: 93min 20sec (5600 seconds)

Published: Tue Aug 13 2019