Atomic Era Radio Teardown, Explained With Repair

hi there and welcome to another episode of mr. Carlson's lab today we're going to check out a really neat looking clock radio combination from the 50s it has that atomic era or atomic age look to it so I'll explain all the controls on the outside of the radio and then we'll go inside the radio and I'll explain exactly how this technology works so let's get started in order to find a clock radio that really represented this atomic era I could hunt high and low and I think was that just a appear store of the left that I found this particular radio it really does just encapsulate that entire area right within this radio it really does echo that era in fact I guess other people are thinking this as well because if you type in General Electric atomic era clock radio on say Google this will come right up this particular radio does and it has all the features in just the coloring and the decor of that and I'm really thankful that I managed to find this because it's in such good condition too so it'll make a really good restoration candidate so to give an idea of what I'm talking about which really kind of spells this era oh this radio was 1955 1956 is when this the production of this radio was happening they changed the design of this radio a little bit the case kind of remained the same but they just changed the face here a little bit and they also had different colors they had kind of up I don't know what you would call it an ivory and off-white color and they came in pink as well and I remember seeing a pink one and I'm kind of upset that I didn't grab it at the time I think the dial was just a little bit different than this at any rate in that era everything was kind of that robin's egg kind of you know light blue and they've you know you can see on the case here they're definitely using it for that it really was the era of the automobile the era of the car and if you look at the the way that they've designed this with these chrome like looking knobs here this looks like a car radio right down here in the bottom they had all the clocks and everything had this kind of a sundial or sunburst look to them and you can see that within the clock here now if you remember the furniture from that 50s era they all have those spindly little legs that were on an angle look at the the plastic extruded area down here they even put those little plastic extruded areas on an angle so it kind of looks like that furniture from way back when so they really did their homework when they put this thing together they tried to just capture everything from that era and put it in here and it obviously worked because these went over quite well you can find these things they're not all that incredibly rare I just I think it's just such a great example if you have a 50s theme room or something like that no this would work perfectly in there now it's really rare to find these things with all the knobs on here all these plastic naughty are very frail and they have these long kind of plastic tabs on them these plastic tabs will break off you know if you kind of force the knob at all if they're stuck so you want to be very careful with them and if they've gone missing they are kind of hard to find I guess nowadays you could probably you know try and 3d print something up that might work okay if you needed to replace them but I really don't think unless you had another parts radio you would find these now the case pretty much remained the same throughout the production years but they did change the way the clock looked in the there is three knobs that were below it or beside it if I remember correctly on that other version but you know they slightly change the look of it the appearance of it but this one here is kind of nice it has this silvery kind of almost like a dashboard look to it so just a really neat Radio now this isn't a bakelite and it's not Catalan radio this is a plastic radio I believe this was made by the General Electric plastics division way back when so the knobs are all pretty generic this controls a volume here this moves the dial around and the dial on this radio is really neat and I haven't plugged this thing in yet I haven't powered it up because it's not safe to do so until these things have been gone through and I'll explain that here when we look inside but I'll light the dial up here in the end and hopefully everything is all the mechanism in there is still working because they've done something really neat with the style so it's kind of abnormal for that time they really did put that quality into this radio so you know sleep timer here and just you know the switch this is also the switch to turn the radio on radio alarm Auto and that this little knob here says push and then hold and I'm really not sure what this does so we'll have to check it open you know discover what this knob does this year you know the standard sleep button listen to that industrial-sized you know switch inside there to take that morning fist when you had to go to work so you know just built really robust I'm very surprised that there is no cracks in the case the case itself is in such nice condition so everything is looking really nice on this thing so you know very good restoration candidate one of the things to take note of too if you want to find a radio like this is if the back is bowed in or these are bent up kind of out of shape there's a good chance that there's a metal heat shield inside this radio that's missing these radios really do get hot there is a lineup of tubes inside here and there's a two tubes in this radio in particular that get extremely hot will cause damage to the case if the actual if the heat shield itself is missing so something to keep in mind if you see that it's boat or these are cracked and bent there's a good chance that somebody removed that heat shield and it's gone had the standard safety interlock cord of the time the reason that these had an interlock cord is because the chassis on these radios is hot which means that it's connected to one side of the AC line and the plug itself is not polarized so you have a 50/50 chance of plugging it in you know the right way or the wrong way so if you plug it in the opposite way everything inside this radio on the chassis would be on the hot line so there is a shock danger there so when these things are to be serviced you have to have an isolation transformer and you got to be very careful I'll go over that when we go inside here so I'm going to do now is get out my screwdriver and I'll remove the screws out of the back case there's only four of them one here one here and there's one down here and one here and this whole case should just come apart and we can take a look at many many years of dust bunnies inside I'll remove the screws from the case here so I imagine that these are all original they're kind of a self-tapping sort of screw here they kind of cut their way into the plastic there's only four of them this is two there and then we have two on the bottom here the bottom ones appear to be a little shorter than the top so something to keep in mind if you're removing these screws and whenever you're putting these cases back together never tighten the screws up super tight just snug is absolutely fine you tighten them up too much and this plastic is well brittle by now so I'll end up cracking so I'll just wiggle this here and we're inside that's what it looks like inside so what I'm going to do is just reposition the camera here and we'll get a closer look here's a closer look at the inside of this radial and immediately you'll notice that they've mounted everything on a circuit board so yes back in 1955 they were mounting components on printed circuit boards now this is a single sided circuit board and they are kind of delicate so whatever components are changed on these things you really need to be careful with your soldering iron in the heat because the traces lift really easily something that's even more interesting about this radio is it has an IC in it back for 1955 it has one of the earliest integrated circuits they were called couplets back in the day they weren't called integrated circuits so what I'm going to do is get a close-up view of that here in just a little bit and I'll explain how that little IC works so for those of you that aren't familiar with vacuum tubes these glass bulbs here are vacuum tubes and vacuum tubes do pretty much the same job that a transistor does nowadays except the vacuum tube is much like a light bulb so in order for a vacuum tube to work these particular vacuum tubes are indirectly heated vacuum tubes and that means that they have a filament structure that's inside of a small pipe inside that vacuum tube and in order for the vacuum tube to work properly that filament has to heat that pipe orange hot in order for the electrons to flow and that's why whenever you have a tube device and you turn the thing on for the first time it takes about 10 to 15 seconds for the thing to warm up before anything happens and that's because that filament has to heat that pipe up orange hot and every one of these tubes are indirectly heated so everyone has to warm up now they're all pretty much warming up at the same time and sensors you know this many tubes I would say the warm up time for this radio is probably going to be about 15 to 20 seconds before any sound really comes out of the speaker now another common thing that people mistake about vacuum tubes is it has a chrome spot on the top of the tube some are a little darker than others but it has a chrome spot sometimes it's on the side of the tube as well that's completely normal that chrome spot has to be there inside the vacuum tube that's placed there when they manufacture the tube so that when it's glowing throughout its lifetime that's absorbing any impurities that are leeching out of the metal and any kind of oxygen or anything that's left in the bulb after they evacuate it and they evacuate the bulbs through these little tips that's the reason to have these tips on the top so that observes the absorb sorry and the impurities inside these tubes so if that gray stuff has gone a chalky white color so basically it looks like it almost falls off the glass and it's gone chalky white that means that the vacuum tube is bad it's it has air inside it and it's used up the getter compound so this is called a getter compound inside the vacuum tube now one of the mistakes that a lot of people make when they're testing vacuum tubes is they don't realize that that white chalky miss Mina the tube is bad and they plug these tubes into a tube tester and they don't work so they let them sit in the tube tester for a long period of time and you know what it does it burns out the transformer in the tube tester so when these vacuum tubes have air inside them it takes a lot more current to try and make that tube light up and some tubes the current goes really really high and it'll destroy a tube tester so back in the day when a tube servicemen or a radio servicemen came around that was going to change tubes he would see that he just immediately know that the tube is bad but you know since there's not very much information about these things out there right now people are trying to test the tubes when they've got a white compound in there and of course they're just damaging their own equipment so if you're going to service a radio like this or change tubes you find a tube that's got kind of a white chalky compound inside you don't test it don't even second-guess it it just is bad that's the way it is now this Gator compound is sometimes on the side of the tube they place it all over and some tubes are even manufactured without that getter compound but there's a larger power tubes that are used in large transmitters and things like that and that's a topic for another time now the vacuum tubes in here again are much like transistors they're pretty much doing the same kind of job this particular radio since it has five tubes in there in series this is known as an all-american five radio that's just what they're called now some of these radios were issued with six tubes and they were called all-american sixes and those were a little bit more expensive because they had one extra tube that would amplify the signal that comes in the antenna so this has got a rod antenna under here we'll look at that here in a little bit and that extra tube was just to give it a bit of extra RF amplification so if you lived in a fringe area something like that it might be beneficial to have one of those tubes ignore one of those 86 radios with that extra tube in it so the tube lineup for a radio like this is pretty much standard some of the radio manufacturers change things around a little bit they would you know put a different number tube in there to kind of stand out from the crowd but they're pretty much all the same so the mixer tube oscillator and mixer tube is a twelve B six and that's this tube right here the the mixer tube or the twelve de six is usually I'd say 99% of the time a closest tube to the main tuning capacitor and the oscillator coil the if' amplifier tube is a 12v a6 another it's just these are all common they're used in a gazillion of these radios all different makes and sizes so this is a 12 B a 6 this is known as an if' amplifier and this tube here is basically taking the signal through this transformer here amplifying it and putting it into this transformer here this tube over here is known as a 12 a v6 there's actually three tubes in one there's 2 diodes in a triode inside this - this is a detector and an audio amplifier a 12 a v6 this is a 50 C 5 this is the audio output tube this tube drives that transformer down there which in turn drives the speaker this tube here and this 35w 4 over here are the tubes that get the hottest in the radio these tubes here just absolutely bake and you can see it's discolored the circuit board down there so very very hot tubes now I was talking about that heat shield earlier in the case and you'll notice here it's up here for a moment reading the case here is that heat shield this is a metal shield if this is missing what'll end up happening is the top will end up melting and you'll get that kind of a saggy the bars on the top or the plastic case will just end up saying in so that's the reason that you know the cases get damaged on these is that shield goes missing again you can see it's over you can see that the circuit board really is discolored down there from the heat so these tubes get very very hot definitely not something that you'd ever want to touch in service that would you know just absolutely burn you these things get very very hot this one here and this 35 W for the 35 W 4 is a rectifier tube and what that does is that takes the AC line so the AC is plugged into here through that interlock and what it does is it takes that it rectifies it changes AC to DC to direct current and then this orange can here filters that out takes out old hum so when you have a radio like this and you turn it on and you know starts to really loudly hum this is the problem right here and this is what destroys this tube over here and it'll also burn traces off the bottom of the circuit board depending on the design and things like that this component in this radio is the troublemaker so what this will do is it will destroy the radio if this is bad here you can see it's been really hot it kind of has a waxy kind of goop on the top of it here so I'm not really too sure if it's you know just dripped off of something here it looks like it may have come out and come around the sides here so this has been very hot and it kinda has a bubble in the center and it's a little bit discolored as well so not something that I would want to leave in here and turn on again if this goes bad it's going to destroy this tube over here and you know I really don't want to destroy any tubes in the front here we can see it has a clock this looks like a shaded pole type motor here getting into the explanation of a shaded pole is really a topic for another discussion so yeah it has two big copper bands here and this is what drives the clock so in many of these older radios these things get noisy because I have a gear box in them and the gear box starts to buzz so hopefully this one here isn't noisy we can see the switch mechanism on here look at the mechanics to that so big switch so looks like there's a some form of a bulb down there under that tape probably a neon bulb looks like it has the standard resistor that would be in line with a neon bulb here and this looks like some that button yeah it's just a push-button switch it looks like that's all it really is is there anything else in there looks like it's just a switch you just push on it so I have to figure out what that is for here in a little bit and the speaker over here and that's pretty much that in order to get at that little early integrated circuit or couplet I need to remove two tubes here so what I'm going to do is just take this tube out it is just gently rock it now it's absolutely fine to touch the glass on these old tubes and they're actually pretty tough if you don't need to worry about it it's not one of those things where you know you need to get your finger prints off them or anything standard glass and we can already see that I see in there look at that there it is with all its little pins on the bottom so that's the little I see right there what I'm going to do is I'm going to take a some compressed air to this thing and get rid of all of this years of grunge a lot of this looks like it's kind of a waxy a waxy compound on the board that's because a lot of the components actually kind of had a wax dip from the factory so the transformer here has a wax coating on it and then they kind of dip these things in wax as well and from the heat from these tubes from years and years and years it gets onto the board and runs around and it makes this dirt really just kind of stick to the board so I'll blow out the dust and everything get that all cleaned off and I may have to use a somewhat of a an aggressive chemical to get the rest of that off to clean it up really well so so what I'll end up doing is removing all the tubes I'll take this one out as well and come out relatively easy and get in there and start cleaning things up in order for me to get the chassis out I'm just going to de solder these wires here first so what we'll do is I'll apply some solder to this first right into this big fuzzy kind of mess that's going on in here maybe asking me why don't you clean the fuzz off the terminals first and my answer would be because it really doesn't matter so it's just going to get inhaled by a desoldering tool at any rate so I'm just adding a lot of solder to the tip here so just fresh solder and then what I'm going to do is grab my desoldering tool here and get it down here and inhale all of that the reason I'm adding fresh solder because the old stuff won't take very well I think it'll probably just come right out there it is and I'll do the same for this whenever you have old dirty solder joints like that it's beneficial to add you solder to it just in order so that they enough so it comes out a little bit easier and not only that Thank You Sol during them like this leaves the holes open so that when you want to put this back together you can just put the two wires back in and away you go so that's these two wires I have to remove this one Brown wire here and then the two off the speaker jack and after that the chassis should come out oh and the knobs themselves are made out of metal the the knobs on the front you hear them so really heavy too so what's the quality behind that so cast something or other you can see that they cast a bunch of numbers into these things so lots of quality there Oh should clean up really nice as well the chassis is removed from the radio and it came out easily so these two wires that you saw me to solder this one down here the two speaker wires and the four screws on the bottom which are here here or here and over here and then of course the removal of those two knobs and just slides right out so it's really dirty and this makes it much much easier to clean this entire chassis up now if I use any kind of a no harsher chemical and to be very careful because there are plastic pieces on here and I definitely don't want to get any on this because this is a plastic as well and actually it's kind of tinted plastic and light shines through it so that's one of the neat things about this dial is this dial points like behind the pointer no matter where you tuned the dial so really neat system so what I'll do is I'll just tune the dial here you can see the entire light mechanism moves with the needle up here and it shines that light through this tinted plastic and just lights up that portion of the dal very neat system so you see on the bottom here this is that tube it gets very very hot this is the audio output to me you can even see that the soldiering is gotten crusty around the pins there so this a little closer to the camera you can probably see that it's broken actual solder itself is broken around the pinion you can see it right there and it's like that all the way around so some aren't as bad as others this one's getting pretty crusty as well so what I'm going to do is get under here and resold er most of this board they did a really nice job on this board look at the conformal coating and everything it's nice and green and really nice circuit board for 1955-56 area that's for sure so and then I'm going to have to replace this capacitor here now I would like to clean this up and leave this on the upper portion of the chassis so this looks completely factory so I might install a few new capacitors on the bottom side and then just hide them underneath the chassis now I need to be careful when I'm doing this just because when I move this you can see that the capacitors right here right so this is going to you know go right over top of it so what I'm going to do is I might have to actually move the capacitors out of the way a little bit I'll see how that goes when I have that all in here and figured out I'll show you exactly what I've done the upper portion of the circuit board has been cleaned and all the components have been cleaned on the top as well I've removed the main filter capacitor here and cleaned it up now this isn't going to be in service this is just going to be on the upper portion of the circuit board for looks there will be two brand-new capacitors hiding on the underside of the chassis so this capacitor is completely disconnected on the bottom side of the circuit board I've also removed both of the if' transformers one sits here and one sits here the reason I've done that is these if' transformers develop a thing called silver mica disease and really what that is is just the migration of metals so what happens is is they've pressed two capacitors into this plastic base here and over time they become intermittent and it makes a staticky sounding radio and sometimes the receiving drops right out so while this is all apart I may as well go in here and basically just disconnect those capacitors that are pressed into the base here and then put two brand new ones on the top and I'll show you exactly how I do that so this is one transformer here and the other one here and they would both sit right in there in order to get one of these if' transformers apart really is quite easy so most of the mechanical drinks that holds this thing together really is a circuit board itself so you know these four pins are soldered into the board and then this little tab here holds everything nice and solid so this really is a soft aluminum shell and all you need to do is just flatten out these little punch marks and that holds this little plastic base inside the aluminum here so if you get just a pair of needle nose pliers and then put it on the side here and then just give them a good squeeze it usually flattens them out if you do that all the way around this will just come out relatively easy so all you need to do is just grab one of the pins here and just rock it back and forth and just pull it out nice and straight like this and you're in now in order to take the rest of this apart it's a good idea to mark everything like you see that I've done here so each one of these pins here on the bottom have a number to them you can see one two and then this is three and four here there's a five and a six in there I think that there were extra pins that could have been added but not to worry about just ignore those just go for the you know the numbers that are closest to the pins and then what you want to do is usually there's a wire that exits on the top of the coil and one that exits on the bottom so what you do is you just mark the pin number that the wire corresponds to it's pretty simple what I've done is I've also drawn a line here as well so you can see there's a line so when I put this thing back together I can align everything up nice and easy and it says mix on it I just wrote mixer here so this is the one closest to the mixer tube they're both really the same coil but it's nice just to put them back in the same spot again so you can see their corresponding this one here actually exits mid coil and then one exits on the bottom here so I mark them both on the bottom but the wires are very close to the number so it makes it very easy another thing that's kind of a bonus is when you D solder these what you want to do is you know use a nice fine pair of tweezers or something like that heat the pin and then just carefully unwrap the wire comes off relatively easy and then if you just leave the wire in this spot and you do this with this one and then you know all the way around when you take this out the wires are just kind of hanging in the same area so put the coil form back in and if you align this little line up all the wires will just point to the right pin so it really does go together quite easily so what I'll do is I'll just do solder all these wires now and then we'll go inside the base here and I'll show you exactly what they've done with those little mica capacitors down in there now that all the wires have been D soldered it's relatively easy to take this out this really isn't mounted in here in any way that's solid it just kind of has a split in the bottom and all you do is you just wiggle this very carefully and pull it straight up and see how the wires they kind of just stay formed the other wires is just kind of stay formed so when you put it back in will just fall right back on to the right pin again so it's still a good idea to mark them though because if you don't you bump it you know it could be a little bit of grief when I put these back together I usually do put just a little bit of superglue on here just a tad on he's sliding them I put it in and make sure it's nice and centered in there a real problem with these is if the little powdered iron slugs inside here which are what adjust these coils if they get a little bit tight what ends up happening is sometimes this spins inside this so it'll start to turn around they have a little guide but that's sometimes not enough then it'll run over that guide and what happens is if this spins it pulls all these wires off inside so it's just a little bit of added protection if you need to ever get a slug out of here it not a big deal one to talk one out and then take the bottom one out of the top so that's a nice little fix that I found works pretty good so what I'm going to do is just move this off to the side here where it's nice and safe put it in an area where the wires really aren't going to get too bent up now a lot of these they haven't marked the capacitors on the schematic and it's a good idea to just measure the capacitor inside usually there's one sometimes they're both good at the time but it's again it's always good to you know check and replace them that's what we're doing right now so what I'm going to do is I've marked that one of the coils comes to these pins here and the other coil comes to these pins here and I've I've Illustrated two dots here and it also makes it a little easier when I'm putting the new capacitors on the top again I can just look for the two dots and I know that one cap goes across here and the other one will go across here and I'll show you that here in a bit so it's very standard for the capacitors in these to be around 100 Pico farad all right just a standard you know what if it's 90 if it's 110 don't worry about it even if it's you know even a little lower than 90 not a big deal just use a 100 and it'll be absolutely fine you don't need to get too incredibly picky with this so what I'm going to do is I'm going to go get a capacitor tester and actually see if these are both good in here before I pull this base apart because the capacitors are hiding right down in here so I'll just go grab that tester and I'll be right back in order to test the capacitors in this plastic base here really is quite simple you need to remove the coil form to do this or at least remove one of the coil wires because the coil is going to short the capacitor right so the capacitor is across each coil so what the coil removed all I'm going to do is just take these two leaves and then just poke them into this area down here on the tester and that should tell me what the capacitor is on one of the sides inside this little plastic base here so I'll put my meter on a 200 Pico farad here now you'll see that I have 3.3 Pico farad of capacitance here that's standard for a meter like this basically it's measuring the capacitance between these two areas right here so you just take it away from the count and we're not dealing with anything that's super high accuracy here anyways right so I'll just put this into here like so so I'll just press this in like that and I don't want to touch these here so I'll hold it over on this side and we'll see what we get and that's 110 Pico farad so if we take away 3.3 we're dealing with 106 point 7 not a big deal so it's 100 Pico farad right it's just moved that's all so these would be a standard 100 Pico farad capacitor on each side in here you know what ninety-nine point nine of these things are like that in these All American five radios that have a 455 K CIF so in order to get the bass apart what we have to do now is we have to get rid of this plastic what they've done is they've heated the plastic here and just kind of pressed it over the sides so when I'm done removing the capacitors here what I'm going to do is just use some superglue to hold this back into place there will be no capacitors under here and I'll end up putting the capacitors on the top where it's easily serviceable in the future again so in order to do that what I need to do is just click this plastic off of here you might want to put on some glasses while you do this because it's kind of brittle and it'll fly off so just make sure that you protect your eyes that one there and basically you're just going to work your way around like so comes off relatively simple another nice thing is to have a good pair of sharp Clippers something that's going to get into here you don't want to be using any kind of a dull clipper you don't really want to damage anything on here you want to put this back together properly again some of them will be a little bit harder to get out than others you can see here and one more and I'm in just about that's why you want to wear glasses okay so now you're gonna want to do is take a small jeweler's screwdriver here and pop it under here get this out of here like so and there's the mica capacitors now you can see why this would have an issue look at what's happening here right now these are just pressed into place with these tabs there's a tab on the bottom from one of the pins and then there's a tab on the top from the other and then the pressure just holds these together so I'll show you what I mean here I'll just bend one of these up that's the only thing that's actually holding these things in place so that's the connection and you can see the connection area here you can see that the connection area is a little bit here in a little bit here and that would be it so you can see where a staticky connection would come over time you can see how this is discolored you know again you know dissimilar metals right and they're just not jiving anymore and this is what creates that staticky mica problem in most of these older radios now the fixed my capacitors are fine because they're sealed but this year again you know it's just basically a press fit and that creates issues so what I'm going to do is just move this one out of the way like so and then just bend them up like that and then this is just a little piece of mica with basically the capacitors right on it we've removed both capacitors here so if you look closely at this you can really see the contact area of each entire strip that would be the contact area there you see the contact area there right there this one here had a little larger contact area it looks to be you can see how it's discoloring here almost tarnishing so that would you know definitely make it bad bad connection and that's going to lead to problems so now what I'm going to do is I'm just going to clip these back here and I'm going to press them back down into place and I'll do that off of camera here I'll clip these and I'll show you exactly what I've done and then I'll reassemble this I'm taking these tabs in the base here and I've just cut them short just a little bit it's a little bit of a gap there the reason that I've actually left the tab in place is just for mechanical strength you can see that I can move the pin up and down here so when I put this back on top here and glue it in place this isn't going to move around it's going to be nice and solid now the reason that you have to cut them short is if you remember correctly they overlap like this and if you were to press this back on top you just create a short-circuit condition without that little mic a spacer in the middle so very important to have that little gap between there so if you want to cut them you basically just bend them up cut them and press them back down again just that easy now I'm going to do is put this back in here again so what I'm going to do is locate the line you can see I've got a line here and there's a line on here so I'll just put this on top like so just press it back down into place and then what I'm going to do is just flood this area with some superglue and that'll hold this nice and tight now the superglue that I use is extremely strong it bonds very fast and it's don't use any kind of a cheap cheap superglue use a decent quality stuff and you'll get good results the stuff I'll use will basically turn this thing into a solid block so that'll be nice and strong for reassembly and then what I'm going to do then is take the little coil align it up again so what I'll do is I'll look for that little line on here which is right here and then I would just put this back in and align it up now I put just a little bit of superglue on here as well and then when I put this back in here again it holds it nice and tight you can see that you know it really isn't all that incredibly tight and if one of these little powdered iron slugs and here got a little bit tight there's a chance that this could twist and if it does it's going to tear these wires off of these posts you definitely don't want to do that so that works very very well no don't go crazy with the superglue on that just just a little bit on each side put it in and make sure it's nice and straight and square and you should be fine so I've got the other one done and I'll just show you that here so this is the other one and the capacitor now is just a cross on the upper side now the capacitors that I use I've got some really good surface mount oh there are 1206 parts is what they are I was going to say Oh 603 but they're actually 1206 parts and I just sold it a little wire onto each side and I mounted them here now these are np0 style capacitors these are rated at 500 volts and they're 100 pico farads so very very good replacement capacitor for what was in there definitely want to use something that is either a my cat or an NP 0 style capacitor for this so what I do is I solder the little wires on each side of the capacitor like that and then I just I put a little bow in there to thermally be couple the capacitor when I'm soldiering it in here because I do have a have a solder connection here and a solar connection here so if it's too close to this when I solder this there's a chance that this may be solder so adding that little bow in there gives a little bit of thermal decoupling and they solder in just fine and that's how they go back together so this is super glue together and that is solid so that'll be a nice solid transformer I'm ready to test the clock in this ol American 5 radio so I have an isolation transformer attached to the clock motor that isolation transformer is also current limited just in case there's something wrong with the windings in the motor or something like that so whenever you're working on an All American 5 or all American six radio it's absolutely important to have an isolation transformer in line with this so you always want an isolation transformer between the line and the device under test which happens to be the radio the reason being for all American five and on American six radios is that one side of the chassis is attached directly to the line so you have a 50/50 chance of putting the chassis of this on the hot side or on the neutral side now if you attach a piece of test gear and the chassis is on the hot side you're going to see a very big flash and bad things will happen to your test gear and if you're between it something very bad will happen to you as well you don't want to you know experience any really bad electric shocks that could be fatal so again you need to take all these precautions if you're unfamiliar with isolation transformers I suggest you do a little bit of research on them and find out why there are so incredibly important and if you're following along you're doing so at your own risk just take care know the risks and precautions of working with this particular type of a chassis again you know there is a 50/50 chance of putting that chassis hot just by plugging in the plug the wrong way because the plugs are polarized both of the the prongs on the plug are the same size so you can put it in this way or put it in this way so what I'm going to do is turn on the power supply right now and we'll see if the clock works so here we go and it does and it's quiet it's dead silent that's really nice using the decent to get noisy over time so which is a really good indication that there's probably really low time on this which makes me wonder if the dial light works so this activates adaiah light by looking at the switch and behind it attached directly to the lamp in there so what I'll do is I'll turn off the lamps here and I'll see if the die light works and no luck this little area right here is the lamp circuit for the clock dial so right underneath this little cover right here is a little bulb that's shining into the corner of this piece of plastic rake down here there's a little piece of plastic and see the edge right here and that's acting as a light pipe and it's carrying the light up to the clock dial itself so kind of like a fiberoptic effect the reason that they have this little cover here is to stop the lamp from shining into the main tuning dial and to also reflect all of the light into that piece of plastic because the little bulb under there really isn't all that bright so whenever you see a bulb that's in series the resistance value like this I'll explain this value here in just a moment that usually indicates that it's a neon bulb that was really common way back when to light up clock dials so I've got the new neon bulb right here this is what a neon looks like these are still pretty common today used in coffee maker switches and in hair dryers and heaters and things like that and it's a little glass bulb two electrodes inside with neon gas in here it's actually a mixture of gas and then they seal the top and it glows a nice kind of mellow orange color not very bright but you know bright enough to be used as an indicator very dependable bulbs when they're you know hooked into circuit properly so the reason that this thing here isn't working is really kind of odd maybe though it wasn't sealed properly right at the base here they have to seal the wires into the glass and sometimes they develop a leak there and then you know they draw air and then it's finished so it's probably what ended up happening with this at any rate it'll get replaced with this little bulb here if the resistor isn't the problem now there has to be a current limiting resistor in line with neon bulbs you can't attach a neon bulb directly to any source reason being is because when the neon bulb itself lights up it draws heavy current once it's LED so we need a current limiting resistor and that's what this does this acts as that current limiting resistor now this resistor here is a carbon composition resistor which is very common for the day we have three colors on it and then an area with nothing and then the end of the resistor body here so that tells us that we read the value this way we read the value towards the gap so orange is the number three we have orange orange and orange so the last band is the multiplier so basically you take that number and just turn it into zeros so we have three three and three so we have three three and three zeros so 33,000 ohms is the resistance value now most modern resistors have a fourth band which is either silver or gold that's very common sometimes you'll get ones that are red as well seen on things like metal film resistors and you know resistors like that that fourth band indicates the tolerance of the resistor or how much the resistance value can vary so if this had a silver band silver represents 10% it can be within 10% of this value so gold would be 5% and red would be 2% those are the most common fourth bands that you'll find on a resistor now finding resistors like this nowadays with no fourth band is very uncommon they just don't make them anymore they always have that band so since this doesn't have a fourth band this is considered as 20% is the tolerance of this so we have 33,000 so we if we take away 20% we get 26,000 400 ohms would be the low end and 39 thousand six hundred ohms would be the top end so if we were to measure this this could be within that range and this would be considered good now this is just in series with a neon bulb it doesn't have to be an accurate device at all and that's the reason that they probably used a resistor with no fourth band again penny-pinching right you don't need that fourth band for something that's going to be just lighting a neon bulb and it could probably save a little bit of money when you're making you know tons and tons of these radios you know that's just a little bit of added savings I guess for for them right there this particular style of resistor is often referred to as an Allen Bradley style carbon composition resistor it's the one with the sharp ends so it's sharply cut off on each end I'll go into more detail and some other videos about these across the neon bulb we have a little green disc style capacitor and the reason that they put that capacitor down there is to eliminate basically contact noise so when you're pressing that little switch the radio doesn't go crack crack or pop pop when you press it and a lot of the time when these bulbs go intermittent they'll Flickr or flutter so if this bulb is fluttering that's going to be putting a noise into the receiver so if you go in crackle crackle crackle every time it's flashing and popping so this here is just a noise filter that's the only reason that they have that there that's a really good idea to have if they would have on this and the you know the ball became intermittent it would make a horrible sounding radio since it's right next to the antenna another antenna sits right over here right and you have all of this acting as you know antenna where in here as we can see the resistors fine 30.6 Kol within tolerance that means that that little neon bulb is faulty so I'll get in there and replace that I'm going to remove the entire clock out of the case so I can clean the dial face as well and I'll use that as an opportunity to get at the gearing here and lubricate the gears of the clock as well they need to be very careful with the lubricants that you use especially around plastic gears you only want to use silicon based lubricants if you use any kind of a standard lubricant on a plastic gear there's a good chance that it will deteriorate over time so something to keep in mind I'm also going to clean the radios doll face right here they need to be very careful around this sometimes the ink that they use on the inside here rubs off very easily now if the radio has been exposed to Sun for any length of time sometimes this even turns into a chalky like substance and basically almost turns into a powder and it'll fall right off so you want to be very very careful when you clean the radios dial face or anything with any kind of numbering or lettering on it some radios even use water decals so if you get water on them they're just finished so if you're going to clean a radio dial like this test in an inconspicuous area I found in some cases where the numbering is very fragile I've had to work around it very carefully with a q-tip and clean it like that some need to be cleaned dry some can be cleaned wet no harsh detergents or anything like that has to be very mild if you can get away with water alone I would strongly suggest that the radio is all finished and pretty much ready for an if' alignment at this point so everything went back together very nicely on the bottom portion here you can see I've mounted the new capacitors underneath the chassis there's lots of room to spare there you'll notice a bunch of changes the factory capacitors are rated at 150 volts that's their maximum working voltage these ones are rated at 450 volts so whenever you're replacing a capacitor you can always go higher in voltage which can't go lower the reason I'm using 450 volt caps is just because I have a lot of these so I'll just use two of these so this basically is just giving me a very large safety margin these capacitors are really overrated for what they're doing no harm in that there's no bean counters here you'll also notice that the capacitors are rated at 47 micro farad's each now in the early designs of this radio they had a capacitor mounted in the bottom side here when the capacitor is mounted in the bottom side things were more point-to-point wired in fact they had capacitors under here as well paper type capacitors paper and foil now the factory schematic had 250 micro farad capacitors and they were tied in exactly where they need to be what they've done is since they've taken everything and put it on top of a circuit board and they've moved the capacitor way over here chances are they may have got a little bit of hum in the circuit because they couldn't attach the capacitors directly where they needed to so they probably up the capacitance value as a patch now 70 micro farad is a little bit tough on the cathode of the 35w 4 tube that's kind of pressing it a little bit so what I've done is I've stuck with the earlier design I would much rather have 250 micro farad capacitors under here it's a little bit easier on the rectifier tube and since they're tied in where they need to be tied in they're not in a remote location and there's no long ground runs over here this here should be absolutely fine the only ill effect that would happen by having this different value here is that the speaker would have hum present in it and I don't think it will I think it'll be absolutely fine again these are where they're supposed to be in circuit or not in a remote location there's no leads leading or traces leading way over to it they also have the ground way over on the other side of the board kind of attached to you know where the if' cans were and everything so again you know they did that to fit everything on the board and I believe that that extra capacitance was probably just a pad we'll find out when we put power to it at any rate I'm ready to apply a/c to the radio to see if it'll work before an alignment which would be kind of nice there's a bunch of different alignment points on All American five radios and I'll explain those when I'm going through the if' alignments those other alignment points are very simple to align now it's absolutely important to have an isolation transformer in line with one of these things before you apply any AC just because there's a risk of the chassis being hot if you're unfamiliar with All American five radio topology I strongly suggest you do any research before you work on one of these things if you're unsure about what you're doing don't work on it because there is a shock hazard so if you're following along you're doing so at your own risk just take care now there's no switch in this thing the switch isn't on the volume control it's actually in the clock dial itself so I have to bypass that particular section so the switch wire comes right down to the top portion of this resistor right here so I tied in here and the other one is the other lead is just tied into the jack in the back here so what I'll do is I'll turn on the AC supply and it'll take a few moments for it to come up because it's vacuum tube radio give it a bit of volume to be nice if it comes to life and it's coming to life I'm four nine radio you can see how that light behind there kind of tracks in the dial as you move the dial really neat little setup that they have on this it is receiving before in alignment which is a really good sign little bit of crackling in there there we go this mechanism is just floating on the chassis so what they should have done is added a ground strap a flexible ground strap from this thing to the chassis that probably stop that so let's see grab one I'll just clip the chassis here convenient area in the back to here see that fixes the problem completely what's happening is there's a little clip on the backside let's turn this down there's a little clip on the back side which is basically spring tensions the bulb into place and that's just dragging on the chassis as this moves back and forth so that should actually have a little flexible piece of you know a braided wire or something on there so that if this does move around it doesn't make that you know crackling noise right so right now this is just grounded to the chassis to keep it quiet so if I remove the ground I don't know why they wouldn't have added that I'm ready to perform an if' alignment on this small receiver now the isolation transformer is attached to the mains this is attached to the isolation transformer so this is completely isolated from the mains right now that's very important because the common lead of my signal generator is attached directly to the frame or to the chassis of this radio the signal lead of the signal generator goes through 12 Pico farad capacitor directly into the antenna tuning portion of this main tuning capacitor this variable capacitor portion Tunes the rod antenna this portion of the capacitor Tunes the oscillator the signal generator is set to 455 kilohertz it's modulated to 50% with a 1000 cycle tone the output of the signal generator is set to 10 millivolts that's available right here now the output can vary a little bit you're just looking for a comfortable signal that will get through the if' chain now any oscilloscope will work even a VT VM or analog movement meter will work for this this is another little trick to make a nice clean signal on your oscilloscope you have to remember that this receiver right now is trying to receive as normal it's just that it has 455 KC's coupled into the antenna section so that will create a very noisy trace on the oscilloscope so what this does here this is acting as a low-pass filter is what this is doing so we have basically a fake speaker here so this is just acting as a load across the audio output transformer since the 215 ohm resistors in parallel now the speaker is 8 ohms it can be closed you know if you have 6 ohms worth of resistance that's fine or 9 ohms that's fine as long as the the audio output transformer is terminated what you want to do is put a 470 micro farad capacitor across these resistors here so basically right across the audio output transformer what that's going to do is that's going to knock out all the highs and the highs is staticky noise and things like that little really clean up the trace on an oscilloscope and if you're using a VT VM to do this measurement as well it'll just steady up the needle now the radio has to be right at 1600 kilohertz or 1.6 megahertz to do this alignment reason being is because this apparatus that's attached to the needle that moves the light around here has to be right between the two if' transformers so that we can access the bottom slugs on these transformers cuz there's for adjustments there's one on the top one on the bottom one on top and one on the bottom of each if' transformer so what we want to do to start is we want to make the receiver as quiet as possible we want to take away its sensitivity so what we're going to do is we're going to take this little capacitor here and we're going to tighten that screw up by tightening that screw up it's going to really reduce the sensitivity of the receiver so basically just slip a screwdriver in there and just snug it tight and that'll quieten things up the first thing that we want to do in the end we're going to have to unwind that again and tune that in order to bring the receiver sensitivity back up worry about that later it's a very simple adjustment so the next thing I'm going to do is take my Scylla scope probe here we'll take a look at the scope I'll just move this over here a little bit so I'll attach my Scylla scope commonly to the chassis because the audio outputs common goes to the chassis as well audio for transformer and I'll click the signal lead clip the signal lead of my oscilloscope to the positive side here like so and if you look at the oscilloscope you can see that there is a sine wave on there that sine wave is an audible sine wave that's a 1000 cycle tone that's coming out of that audio transformer now you can vary the amplitude by adjusting the volume control so if you adjust the if' and you find that it starts to get really big you're going to be able to turn the volume down you can see I can adjust the amplitude you can see it starts to look kind of like a sawtooth almost there that means that it's over driving so we're going to do is just turn this down onto the you know to a comfortable level till we have a nice clean line wave and then I'm going to take my adjustment tool here now I've adjusted the bottom slugs on these transformers just because this is very hard to do on camera and maneuver everything so I'll just adjust the top slugs and that will give you an idea of what to look for so you need an insulated tuning tool it's very important you don't want to use any kind of a metal tuning tool in this because the slugs inside these Transformers the slug is just another name for the adjustment it's a powdered iron core and they're brittle like glass so if you break one of these things by sticking a metal screwdriver in what happens is they crack in half inside that cardboard tube in there that paper tube so when you want to move it when you stick a screwdriver in there and turn it it presses the two halves apart it acts like a break in that little core and they're very hard to get out so you don't want to take any chances by using a metal tool and not only that some metal tools are a little bit magnetic and that'll also detune this when you stick the tool in there and when you remove the tool you'll notice that it'll go back into tune so you got to use a plastic tool on all of these it's better to break this little plastic tip than it is to break that slug so in the future I'm going to do a complete video on removing broken slugs out of Transformers and in if you have a seized if' transformer or an RF transformer with a powdered iron core or slug in it I'll go over that as well how to basically free up those cores so what we're doing right now if you take a look at the oscilloscope screen we're looking for the highest amplitude is all we're looking for so you can use any old oscilloscope for this we'll vacuum tube oscilloscope I've got one from the 30s that would work just fine so you're just tuning it so you're going to turn this one way so now we know that we're going the wrong way because we want more amplitude so we're going to turn the screwdriver the other way and you can see how that's getting large we just tuned it till we get a peak if we pass the peak we go back and bring it to the peak just like that now for the second adjustment we would go on the underside and poke this through the underside and tuned for a peak again now we can jump right over to this other transformer and tune the bottom slug on it as well because we're just looking for maximum amplitude and then we would come back up to the top here again and then we would adjust this so it doesn't really matter the order as long as you start with this one here because this one is closest to the signal so we want to peak this one first and then we go over to this one this one is closest to the output so I'm going to drop screwdriver in to this little slug here and I'll tune this for maximum signal as well and you can see that we're out on both right about there is the maximum so once you've peaked everything and you tune for a maximum it's a good idea to just to go over it one more time so we would start here again and just make sure that we're at our maximum right about there is the maximum n RI F would be tuned just that easy so you always want to start with the if' transformer closest to the signal and again you go from the top to the bottom if you want you can jump from the bottom to the bottom on this one and then come back to the top it would be absolutely fine now I'll demonstrate the importance of tightening this up if there is a radio station at the top end here you'll start to see that trace on the oscilloscope jump around so I'll just loosen this back up so the receiver gets sensitive again and you can see how it's starting to jump around a little bit if I actually tune this into a radio station that was active it would be very hard to tune this because there would be so much movement here I'll just try and move this over a bit I can find a radio station or something you can see that so that's the whole idea of basically reducing the sensitivity here this adjustment here adjusts the oscillator tracking so if the needle isn't aligning too said on the dial face so say this was supposed to be at a thousand kilohertz alright so and it was sitting off at maybe 1200 you would adjust this first of all you would tune this to 1000 make sure to write on 1000 and then you would tune this until you hear 1000 kilohertz or 1000 a.m. one mega hurt until you hear that until it's right on frequency and then that adjusts the dial tracking this is usually done at the top end of the band so you usually align this up at 1600 you can use a signal generator for this as well if you want or you can just use a local radio station now in order to tune this back up again what you would do is just tune this right to the top end of the band very simple and then all you need to do is tune this for maximum hiss or noise so you really don't need a signal generator to make this sensitive again you just tune this until it gets really static you're noisy and I'll demonstrate that here in a little bit if you want to use a signal generator to do this it's absolutely fine to do that as well you can monitor the output on the oscilloscope the exact same way that we're doing this right now I don't have any radio stations up at 1600 a.m. that are close enough to actually do this alignment so basically just static and noise right now so I'll just use my signal generator instead so what I've done is I've just loosely coupled my signal generator right close to the antenna wire the signal generator is now at 1600 a.m. or 1.6 mega Hertz however you want to look at that that's modulated to 50% by that 1000 cycle tone that we were using for the if' alignment and I have the output just set to a comfortable level to where the radio will hear the signal generator so what I'm going to do is turn up the volume here and hear the static the radio is pointing rate at 1600 a.m. right now and it's not hearing the signal generator which means that the oscillator is out of alignment so what I'm going to do is just tune the radio dial you'll see the capacitor move here until I find it and there it is so that's pointing to 1400 a.m. so that's quite a ways off so what I want to do is bring the dial back up to 1600 so now the radio is pointing rate at 1600 a.m. I'll turn up the volume and I'm going to adjust the oscillator right here so I'll adjust that adjustment so here we go I just want to adjust this until it gets to its loudest point right there so now the dial is adjusted now the dials on these radios are never really super super accurate so as long as it's pointing very close to the number you're doing pretty good they're all American Pfizer usually like this now there are ways if you really want to spend some time with this you can start trying to bend plates on the main tuning capacitor and everything but you don't chances are this is going to be so closest not even worth doing that so now if you remember earlier we desensitize the receiver by turning this tremor capacitor in here so we want to bring the receive back again so I'm just going to tune for a loudest signal so I'll turn the volume up again and I'll just turn this until it gets to its loudest point right there so now the receiver is about as sensitive as it's going to get it's gone through an entire alignment now you don't need to use a signal generator to align this one particular portion the antenna portion you can just tune for maximum static or maximum noise so I'll turn the signal generator off I'll turn the volume up and I'll give you an example here so the tune it you tune it again right there is maximum noise so you can see it ends up in the exact same spot so the radio is now completely aligned let's take a trip through the broadcast band so as you can hear the radio is really quiet it has virtually no hum so those 247 micro farad capacitors that were installed are absolutely fine so I'll turn the volume up here you can hear it's just a little bit of volume it's really trying to receive so here we go [Music] to May 30 I am that them please take down officers arrest wasn't after by the province okay but the babies aren't necessarily flush in these creatures stay tuned I think we're we're getting very quick [Applause] [Music] from WCDMA [Music] so as you can hear it's working very very well and that's just on a little internal rod antenna and believe me anything that doesn't have an external antenna here in the lab just really has a hard time receiving and Ronn antennas are very directional as well so if you have a radio with a rod antenna in it it's not receiving the station that you want to hear very well try rotating the radio a little bit and see if you can get the radio station to come in just a little bit better so all in all I'm very very happy with the project it works very well and the clock everything is just functioning great I'd show you how this lights up but it's extremely dim with that neon bulb so in order to see the clock dial would have to be in a very dark room but the neon bulb was faulty and it does work now thanks for stopping by the lab today hope you enjoyed the explanation of this atomic era clock radio combination if you did you can let me know by giving me a big thumbs up and hang around will be many more explanations like this coming in the near future talking about all sorts of different electronics technologies vacuum tube stuff and solid-state alike if you're really into this stuff don't forget to hit the subscribe button as well if you're interested in taking your electronics knowledge to the next level I have an ongoing electronics course on patreon right now I'll link that just below this video in the description right about here if you do go there don't forget to check out the community section too there's many people sharing their electronics projects there so until next time take care bye for now you

Channel: Mr Carlson's Lab

Views: 238,568

Keywords: all american 5, all american five, AA5 receiver, AA5 radio, Atomic Era, AA5 alignment, AA5 repair, IF alignment, oscilloscope alignment, signal generator alignment

Id: P3Wh41Mbf9A

Length: 70min 55sec (4255 seconds)

Published: Sun May 07 2017