Trying to Fix A GE Tube Radio Without Replacing The Capacitors First!

ladies and gentlemen this is Joe's classic video games back with another cool radio repair video for you this evening now this is an amateur radio repair I do not know what I'm doing so keep that in mind as we go through I'm trying to get this thing to work this is an old I don't even know when the thing was made I would guess early 50s I guess maybe I should look that up huh it's a model 475 I wonder if that means it was made in 1947 I don't know it looks a little newer than that to me but uh so I've been messing around with this General Electric model 475 AM radio and um I don't really know what I'm doing so it's amateur repair time so on the previous video I took the chassis out uh I'm operating on a theory here or on not a theory on a on a um premise here I a lot of people repair these and the first thing they do is they put a cap kit in it and then they fix whatever's not working I'm trying to do it the other way I'm trying to figure out what's wrong with it and then once I get it playing badly put a cap kit in it and then I can hear what each cap does I'm trying to learn by working on this thing so on the previous video uh I took the chassis out I cut the across the line capacitor out of it just in case just so that won't explode on us or anything uh that one can get kind of dangerous from what I understand the uh and then I checked all the other caps just to see if any of them were dead shorts now they're probably all leaking and messed up and they all need to be replaced but uh I'm trying to get it limping along and then I want want to replace them one at a time so I can see what changes as we do that right that may or may not prove effective but we'll see I just whenever people just blindly put cap kits in them I've got a lot of um I've got a lot of history uh repairing arcade game monitors and I learned after several years that people think a cap kit will fix a non-working Monitor and that's not usually true usually there's something else going on so you kind of need to know how the thing works and then yeah you replace the Caps so that you get a nice reliable um monitor you know and it'll do things like clear up Geometry issues and stuff like that but in general it doesn't usually fix something unless the filter Caps or the you know cap capacitors um in the the high voltage are just so screwed up that it's got everything messed up so I I assume that the radios are kind of similar to that too so I took that cap out there was another and then I checked all the Caps just looking to see if any of them had shorts nothing was really shorted I did find one this capacitor which one was it this capacitor right here C10 that only measured like 15 ohms now I know that's not how you test a capacitor but again I'm just looking for ones that are you know like a paper cap that's shorted or something that's going to cause serious problems if you power it up that way so I couldn't find any this one tested where it had about 15 ohms but it's because it's it appears to be because it's connected to this uh M4 here which is actually a potentiometer it looks like it's some kind of sliding switch or something but it's not so I don't know these are probably these may be the wrong schematics or something or maybe there were a couple versions of the same radio um so I replaced that one cap after I cut it out because it didn't fix fix my short that I measured on the cap so I put in a new one so we've got one new cap in the radio everything seemed all right I powered it up on a variac it came up and uh just got the typical humming there's no um there's no front end at all however while we were doing that I ran into this problem with the antenna now I believe L1 to be the antenna but I don't have the other page of this schematic where they give you the legend so I'm not really sure what L1 is but I think L1 that looks to me like the antenna and it kind of seems that way the antenna on this one someone has disconnected cut wires done all kinds of crap C and I'm measuring a direct a dead short across the antenna whenever one of the wires is one of one end is disconnected so it's like it's all shorted together now it is just a coil of wire around a ferite core so you know it is connected from one end to the other but I don't think it should be a dead short so I think that may have something to do with why I'm not getting any kind of front end um reception I think that antenna the something's wrong with it or it's wired up wrong or something so let me pop the chassis back out of this uh case the leads to the speakers are really short where you can't work on it outside of the case so I'm just going to get some jumper wires and some little alligator clips and run it to the speaker whenever we get ready to power it back up but we need to figure out that antenna thing first so let me pop it back out and we'll check that so here's the antenna mounted on the back of this thing and we it's got a local and a distance switch I kind of want to figure out what that is I believe it may be that switch right so uh I need to figure that out but let me show you how the antenna is hooked up at the moment all right so we have four wires one is down here and then it runs all the way down this and it's this wire here this is running from this end I it I think right this was disconnected when I got the thing the radio looks it's got a couple things where people have obvious been working on it but all the Caps were original everything underneath looked pretty original this was disconnected but it looked like it was just broke off so I cleaned it up and put it back okay now before I did that though I measured from here to here which appears to be the other end of the of the uh antenna and it was a direct short I would think that it you know you're not you can't really uh measure impedance with a multimeter but you know I was expecting you'd get four or five ohms resistance I've got another radio with a loop antenna on it and I think it's like four or five ohms so I thought maybe I'd get something similar I don't it's like it's a dead short so I think we need to look at that bar and see what's going on so the other end is this connection here not that one this one appears to be this connection um which isn't even hooked to anything and then we've got this connection don't know what it is that they've got running to here on the on the uh condenser here and then this one or uh this red one look at this crap it's going to the chassis attaches to that which is attached to the the this cover here so anyway I think that's all screwed up so I'm going to go ahead and take that cover off and be very careful and try not to break the rod and all of that and then maybe we can get a better idea of how the thing is supposed to hook up once I can actually see it okay so this cover came off pretty easy so uh the wire that is here it needs to be cleaned up but ultimately it is connected to the frame okay that makes sense to me and I think I see our problem the this end does appear to be connected [Music] here boy I'm going to win a cinematography award for this oh wait a minute is it not connected I don't know if that's the proper place to connect it we're going to end up pulling this whole thing off but so is this pin connected to that pin Focus so you can see the wire clear as day connected to here but does that connect to there so we'll figure that out and then on this end you can see the wire connected to there which is this wire that is not connected to anything right now so that would be our problem that would connect to the other part you would think unless if that is connected to that then it's m in the hill so yeah so we got some issues so I'm going to check this with a multimeter and see if I'm see if these two are connected and if those two are connected and what the deal is all right so I was able to pull it Loose now remember I'm an amateur I haven't messed with this stuff um this little clip that is connected to that so it's just made like that this little ring is holding it in place okay so this wire whether it's connected there or there doesn't matter it's the same connection and then of course you got the [Music] wire down on this end it's a little loose it must have broke at some point and they soldered it back or something but same story down here this connection is the same as this connection so this wire is not actually hooked to anything it may have been for like an external wire or something but this wire is and it is the one that's running down here uh to the set screw basically I think that's the stat and this is the uh the frame which is running to the other end so I'm getting 8 ohms resistance on this that just seems really low to me so but it's not a dead short so but that's pretty close to a dead short so that kind of looks like that's correct I mean maybe there is only less than 1 ohm resistance in that wire it's not really all that you know it's probably uh how many turns is that one two three four five six seven 8 nine 10 20 30 40 it's maybe 150 turns and you know each turn is maybe an inch and a half so it's like a 10 or 12 foot wire and I'm thinking there's 1 ohm resistance I don't um that could be about right so maybe I'm barking up the wrong tree so if that's not the problem why we don't have anything on our front end maybe we should look elsewhere what do you think I mean we don't get nothing we just get M no kind of change whenever you try to tune something in so maybe we have a resistor burn up or maybe we have a tube Loos in its socket or a bad tube right so I believe this would is the co NV I believe means convert M maybe and this is our first if amp Transformer our second if amp Transformer and an if amp um tube and then uh the detector the auto volume control and the AF amp tube and then our output tube I mean you know if it's if if we're getting amplification really all that tells us is that the speaker's good the output Transformer's probably good and the output uh uh tube is probably good so all of this could have problems the volume control works what does that tell us does that tell us that our AF amp is probably working um so I think maybe what we do is I put the antenna back and then uh we turn it on and we wiggle some tubes I don't know maybe I should check some let me run through some of these resistors while it's off and just check and see if any of these resistors seem way out of spec and I'll focus on the ones here um there's one there and there's one [Music] there yeah I'll just focus on some of this stuff it could be too that something like c7's open if you look that would wouldn't that get rid of that would kill the whole front end wouldn't it so it could ultimately end up being something that a cap kit will fix but i' just like to learn something about it before I uh before I just shotgun everything you know all right so let me check some resisters if I find anything interesting I'll let you know okay so again I don't really know what I'm doing but um I'm trying to go through and check these resistors this is kind of right but it's a little different so for instance you've got this switch here which I think has something to do with the distance or Loc thing I may be wrong about that it kind of almost looks like it would be a tone switch I don't know because it you know I don't know but anyway this switch if that is that switch uh there is a resistor coming off of it that is green green brown I believe that to be green green brown is that green green brown so if that's green green brown that would be 550 and I'm measuring like one and a half Meg ohms so if all the audio were to run through that I mean that or if the if all the signal were to run through that it would mess it up but I don't you know I don't know about that and then some of this other stuff isn't lining up with with what I've got on these schematics it's similar like I've got this but I don't think it connects to there so I don't something all right so I think I'm going to clip that resistor out or one end of it out and just confirm that it's not measuring 550 o okay yeah so I confirmed I uh desoldered one side it says 500 50 ohm best I can tell that's what that color code is come on people green green brown come on now that's 550 ohm anyway you look at it and it's measuring 1.5 Meg okay so I'm looking going where the hell is there a 550 Ohm resistor you know and I see this one as a 55 Ohm resistor but it's nothing like that so then I finally start thinking about it now y'all may have figured this out on video one but like I said I'm a I'm a a new one I got the [Music] 475 from I believe I think I've got this right I got the 475 from the eBay ad where I bought this radio a year ago it's been sitting around as you can tell I've got a lot of radios I'm trying to fix one of them so I can hear something that's where I got that number from now looking at the pictures on uh radio Museum it appears right one two three four five one two 3 4 five six come on come on people it's not a for people it can't be come on people it must not be a 47 look at it it's got do you see them you see what I'm saying it there's five and it's got six there's an extra one somewhere okay one two three four five these ain't the right schematics what are they doing to me at the radiomuseum.org what are they doing but you know General Electric that wasn't a big company or anything I'm sure it'll be real easy to find which one this actually is all right so there no big deal I mean all I got to do is just go look at the General Electric models radio catalog for the radio manufacturer General Electric Company GE so there's probably just a few and then I'll I'll I'll look at the ones that are like I'll look at the pictures and then match it to that so there are uh there apparently they made 2842 different models of General Electric all right now we're getting somewhere so I went and I looked and the picture did look like a 475 but it has six tubes so I went and just uh looked at the list by number on uh the radio Museum and it looks like one was made that same year or the next year there was a model 480 that had six tubes looking at the picture of the 480 it looks just like mine so I think whoever listed it on eBay just made that mistake uh and this schematic seems to match what I've got so it's fixed a couple of my problems that I couldn't figure out like for instance that distance switch is labeled and my phono and radio control is labeled so this is all different than the way that it was uh in the other schematics they were very similar but there was pieces missing okay and then if you look at the radio thing there is in fact supposed to be a 1.5 megga resistor so my green green crap apparently I read something wrong I think what I where I messed up was it was a uh the the it had a brown stripe at the other end I was reading it backwards so it wasn't green green brown I thought the brown was blending in with the with the um with the body color of the resistor it wasn't if you look real close there's a brown stripe right on the end so that's the one and then the green is the five and then the five after that would be let me think uh uh to the fifth decimal point basically so it would be uh one how would we do that math I can do it with a piece of paper pretty easy but um so if there's a one then it would be 150 if there's a two it would be 1500 if there's a three it would be 15,000 which would be 15K [Music] uh and if if there was a yeah so if there was if there was a green stripe it is a 1.5 Meg I was just reading it completely backwards see I got to solder that back in thankfully I didn't clip it all the way off I just unhooked it so I put that back there was absolutely nothing wrong with that so obviously this is amateur repair time people on amateur repair time we make lots of mistakes cuz we're amateurs we don't know what the hell we're doing all right but I'm learning so now I know if you buy a radio make sure it's the right one and one of the easy ways to do that is to count the freaking tubes all right so now we're a little back on track but you know what look at this here is my antenna and would you look at that it now has an extra wire drawn in that connects to the B minus B minus and the chassis and the B minus are connected by a capacitor H okay so yeah with that extra wire drawn in that does look remarkably similar to my antenna hookup [Music] so we'll go from there so I think basically I just need to like I said keep checking resistors and now everything should line up a little better I'll print this out and uh I'll see if I can find anything with it turned off and if not uh I guess we could pull tubes and start checking tubes okay so with the new schematic I've been hard at work look at my little jumpers I had to make for the speaker can you believe that you'd think I'd have somewhere some alligator clips but I do not at this location so I need to get some little test Clips okay so I went through and I started checking all of the resistors and most of them are correct there's a few that are out of spec like for instance this one's 100 oh it's 119 know that's a little high they're all like a little off you know 5% or so um okay but so I checked them all and I'm checking them in circuit so they could be if you check them in circuit usually it's not going to make them too high it might make them too low but I mean it things can happen if they're right next to a capacitor I've had that happen where it checks like it it just checks like it's screwed up but then whenever you take it out it's fine because basically your your meter is trying to charge the capacitor okay so this one here uh on the if amp tube to ground pin seven there is 182 ohms is supposed to be 120 again that's high and it should be replaced but it's not it shouldn't shut the whole thing down all right and then this big uh 2 watt 1K resistor is at 1.4k so that's pretty off but not the end of the world but here's what happened all of those checked out pretty decent and like I said I checked the Caps I put a little check mark by the one cap that I had to replace last time CU I cut the old one out um so none of the Caps test shorted and again that's not the right way to test them but I'm just trying to make sure it's hopefully not going to blow up on me so then I started checking voltages so I hooked it up to my variac here the main reason I'm using that we already used it before just to make sure that everything was cool um the main reason I'm using it now is because it has a fuse in it and I don't have a um a u amp meter hooked up to it but we got a fuse in it so I got that dialed up to 112 112 volts that's about right isn't it but here's the thing it comes up and it hums but on the other side of this rectifier it's only 94 volts it's supposed to be 125 and then it goes through this resistor anounced down to 86 volts which sounds about right um that could be I think this cap going south on us could be drawing the voltage down but tell me about this you people that know what you're doing tell me about this this is a number 44 bulb that's the same bulb that's in a pinball machine so I know that's a 6.3 volt bulb and and if you look again I don't know what I'm doing I'm a novice the two basically that voltage there is coming off of this tube it's another it's a separate tap um and we're at 2.7 so surely that thing's supposed to be putting out five or six I would think that's suspiciously I mean that kind of looks like half to me so I'm thinking maybe we got a problem with our rectifier tube so maybe it it could be this cap so what I'm going to do is I'm going to test the rectifier tube and swap another one in and if I get similar results there then I'm going to go ahead and replace that cap I mean I got to replace them anyway but like I said I'm trying to learn right so this hopefully this will help me figureing out so next up we got to test the tube all right I've got a few tube testers um I think I've got four or five of them actually but the first one is a IO 625 I got this from a gentleman who passed away about a year year and a half ago his name was Bob and uh he was all into ham and Tube radios and stuff like that and so I got a whole bunch of equipment from his son after he passed away and um I've never tested some of this stuff so I'm going through it now and checking it out so uh I set up the line adjustment here and then this is a 35 W4 so I set the shunt on 20 and the filament on 32 shunt on 20 filament is on 32 uh selector three uh five is up and four six and seven are down four and six have a line under them H so we are getting a little bit of glow so it's at least lighting it up but I don't know what you hit to test it on my other one you hit a button to test it I mean we got this one what do you think short Merit it says oh yeah okay there we go so yeah it tests fine but I cheated I Googled it and I found a bunch of people saying that these 35 w4s are suspect and that they've had several of them that test perfectly fine but you put it in and you get a low output voltage so I'm going to try swapping in another one but it looks like if this if this uh if Mr Bob's old school uh IO 625 works it's telling me that thing strong of course it's just a rectifier tube so you wouldn't think that it would um well I don't know I guess they get weak right of course it could have just been dirty in the socket too all right so let me try swapping another one in I'll test another one and um we'll try swapping it in and see if we get any different voltages all right so I've got a new 35 W4 and either it's also very good or this meter says everything's very good all right fired it up check the voltages real quick same exact voltages they're very close so it's not that tube so it's it could just be the electrolytic cap it doesn't test shorted but if it's really leaky I guess it could be pulling this down so that's supposed to be 125 that maybe over here would be 118 or something like that I don't know and if that cap is messed up it would make that closer to ground right which would be more like 86 so um I'm going to pull the other four tubes I me other five tubes and just test them on the the the thing just in the in the off chance that I've got a um you know maybe I've got a a tube somewhere that's causing all kinds of problems but since I'm not even getting the voltage out of here that I'm supposed to and I'm still got the the deal with the only 2.7 where I should have about six something is really pulling this thing down and it's probably that but it could be I don't know it could be something like and again I have no clue what I'm doing but it could be something like this tube instead of using its 12 volts that it's supposed to use it's using 40 volts or something or 50 volts and it's pulling all of the other tubes Supply down or something okay so I'm going to test the rest of them and see if I can find anything that jumps out at me um but it's about time to order some caps and resistors and maybe two we'll figure it out folks don't worry about it we're going to get it okay folks I I started testing the tubes um I've got a bunch of tubes I've got tons of them but that doesn't mean they're any good right so I tested this one it's decent uh tested this one not good tested this one pretty weak this is the same one pretty weak so the RF amp and the ifm both pretty weak so I swapped them with ones that I had that were marginally better I mean I've got a whole ton of tubes I mean I've probably got 2,000 tubes but most of them are stuff that you can't even use or they're for TVs and I don't know anything about TV repair tube TV repair uh and then this 12 be6 also tested weak as hell so I you know it kind of makes me question the tester you know it was testing this rectifier tube and given us strong results on that and it gave us pretty strong results on two of these two of the tests on the triodes the two of the things seem to be testing all right so I don't know but I I think it's completely believable too that I got a bunch of worn out tubes and a lot of these other ones like I've got some in boxes but they've got labels people have written on them and they're not New Old Stock it's just stuff that somebody saved I do have some New Old Stock ones but like this one was a u 12 ba6 so you know somebody saved that one because it tested good 40 years ago and now here I am trying to test it so I put I replaced uh we replaced that one I replaced that one and I replaced that one um and I replaced that one so I've replaced one two three I replaced the four tubes of the front end so let's see what we got now I don't want to leave it on too long because you know big papa there might decide to explode on us or something it's on but that bulb is so D so I think it's still got the the voltage problem are we oh no here we go boy she's humming let's see if we can get anything yeah it's changing now you hear that I hear oscillation a little bit there's something going on one possible conversation starter or topic for your consideration and it has to do with strangers someone sent me a real uh from Instagram I believe it was and in the Reel I got to working radio now maybe in his 40s was telling a story about okay so I need to order caps and stuff and I guess I'll order some tubes let me try to get some decent tubes in here so I need some 12 ba a6s some 12 be6s some 12 a6s some 35 c5s and some 35 w4s I I guess I need I've got a ton of these and uh I I had some of these too but since it was actually testing that it was fine it just wasn't great wow that's pretty cool so I guess uh bad tubes I would not have thought that I would have thought um that we had an open cap somewhere or something and it could have just been that the tubes weren't in the sockets very well I wiggled them a little bit before we started messing with it but all right folks so we got the thing to at least pick up a a radio station so I'll call that [Laughter] done you know there's accidental amateur repair and then they're servicing it that's a whole other story so we'll do that in in the next video right so uh I think we repaired it by accidentally finding a tube that was bad by the way I used another tu tube tester and this uh 12 va6 is dead dead and more dead gets filament voltage running through it the filament's not open but the output is just gone so one of these 12 b6s was probably the problem probably the problem I got a that's a new uh Roger millerism I got to remember probably a problem okay so it was either the if amp or the RF AMP one of these two if I was going to guess and I don't know what I'm doing um it kind of looks like the volume control might be dependent upon the well no both of those are completely before that so it could have been either one of them I guess one of the two I the if amp or the RF amp was completely shot right so that's that so leave your comments below let me know what you think so far we'll do another video I've ordered caps and stuff so we'll do another video where we recap it um before I blow the thing up running it on the old filter cap uh so we'll do we'll do another video where we do that if you've seen this video that means I've already finished the other video because I don't like uploading if I've got videos in a string you know three or four I think this is the second one if I've got a string of videos I like finishing the whole thing before I upload it so if uh I won't leave you hanging right so the other video is coming but I'm going to do a video where uh we'll order in some caps and uh we'll replace the Caps I think I want to replace them one by one just to see which ones seem to have the biggest effect I would assume that the the filter cap will but we'll see um but I'd like to go through it one by one and uh do the best I can with it and then turn it on after each cap and see what we got so we'll do that in the next video and then I got to align it and I still got to mess with this freaking dial cord so let me know what you think this is this is an amateur repair Time video folks so we're amateurs around here we're not trying to say this is the way to do it we don't know the way to do it completely amateur so leave whatever comments you want down below make sure to give us a thumbs up for taking the trouble to film it for you and if you haven't already check out my brother Donnie my brother has his own channel here on YouTube a guy asked me the other day well what's the name of his channel my brother Donnie is the name of the channel the Link's down below um so I hope you enjoyed it check out his channel I work on arcade games pinball machines jukeboxes and amateur dabble and stuff like this although I don't know what I'm doing Donnie works on Old Vehicles old build buildings things like that and I'm over there with him on his channel a lot so go check that out and we will see you here in a couple days with a more traditional arcade game Pinball or jukebox video so we'll see you then I hope you enjoyed it we're just trying to have fun folks