1948 Hoffman Radio TV Set Ressurection Pt1 Acquisition Analysis Radio Repair

let's see how close I got this oh there it is holy crap it's right there I'm gonna let me see how to do this I brought a hand truck I'm just gonna pull up right here and try and get this have to do it just as quick as I can I don't want to block the car wash they're great the only reason I'm getting this is because I have another one oh this is not the same this is not the same and yes some of the tubes are missing okay I just get it it's on a house a street with a bunch of abandoned houses these don't look abandoned to me maybe that is yeah those are a band and these are something's up with these here's a deal if the CRT and this Hoffman is no good it's going straight into the dumpster if the CRT is usable will resurrect it I have a feeling this might have gone to air yeah it is actually glowing and that's you know these bet metal these metal cone CRTs they like to go to air so and it is actually producing a little bit of emission so this might be resurrect about okay this is marginally acceptable this will produce a picture so we'll have to resurrect this thing to find a schematic for it because I don't know what what tubes are missing there I have no idea what those are the homeless have been using this the same way a dog uses a hydrant so it kind of stinks it's been the local pissing post so yeah it's definitely not restoration at least not for me turn it off baby boomer all right we're going to resurrect the Hoffmann Street find homeless piss post set am/fm radio like I believe it's am/fm it is am/fm and easy vision lens and what a beautifully built no-expense-spared set this is with all of the brass plates that are screwed on this is or this was a very gorgeous set and the objective of a resurrection is just to make it work again it's probably promptly going to go in the dump except the CRT I'm going to keep the CRT because I have another one of these that has a weak CRT but is in decent shape if you look at the condition of the speaker there you can see how bad it is so the first thing we need to do to resurrect this is find a schematic on it and the model and chassis number are completely illegible there's the chassis chassis who knows so I've already October 1948 right 1940 or 1946 anyway I believe I identified this chassis because we're missing somebody pulled it looks like at least four tubes out of this so I believe I found it in the writers volume seven I believe this is it right here 1:53 is a 28 to TV receiver the high voltage and deflection circuits are specially designed to operate the 19-inch picture tube I'm not gonna read that whole description anyway that's a chassis 153 and if we look here that could be 153 or 157 I don't know I can't really tell there is a 157 but they look a little different they're a rectangular tube set I think it's a 153 okay this one's a little different because this one has the tuning gang up there for the am/fm radio mine has a power amplifier down here in the bottom and I don't know if maybe someone removed that okay I was reading through this and it says that the chassis z' are pretty much the same except you could add an am/fm a3 tube see here this one with am/fm tuner so the only thing that's important right now is all these tube layouts are the same so I'm gonna write down on the chassis what tubes are missing okay so that was the right thing in there so we're missing two v u fours which are in parallel I can just make a solid-state replacement for those for resurrection and testing purposes and then I need two 6s n 7s so on this one it looks like maybe someone who knew what they were doing yanked the tubes gotta love this huge soft asbestos sheet look at the size of this thing that is pure cancer right there soft asbestos should probably get that wet and get it out of there it's like someone cut the high voltage wire and the chassis is loose for those can dorm resistors holy crap look at the size of those candle resistors look at all of the capacitors in this layers and layers of crappy paper capacitors and bumblebees the transformer looks kind of burnt that transformer there looks kind of baked also Wow so this is probably audio output right here or a choke okay this must be audio output okay so this looks like it's the audio output transformer and it connects to these wires which go to here so this must be the speaker connection okay that looks bodged in there I guess that was may have been replaced and just take the air compressor to this and blow it out but like I said it's a resurrection the goal is not to recap it and make it nice is just to make it play again one last time before it's sacrificed to the copper scrapping gods okay here is this must have been where the am loop antenna hooked up this is the three tube am/fm tuner okay what I'm interested in is this high voltage lead they cut why why you would cut this it's no problem I have plenty of wire off of this thing is hacked up the boy that's klinke dinkler that's two key clue ker look at that banana slicer this is the boring observation part of our show so here's the slide for that and that's frozen see this is the audio output tube the 6j ooh why this has got some hours on a look at the burn off there that's those dots are from filament evaporation that's how many hours are on this a 6 SN 7 baked so this thing's got some hours on it you know what's up with all these capacitors as always have to feature the dead spiders you know so this capacitor looks like it's been replaced you can see the solder or the hacksaw door job and maybe this one too look at that right there this thing has definitely had its share of work done on it this capacitors definitely been replaced look at that this is what you call a very high hour set this has had a lot of work done on it that looks like that's been replaced or maybe deleted wonder what happened there where that capacitor actually looks like it's wrinkled Wow wonder what this goes to or is that my speaker wire yeah that's my speaker wire we got a spider eggs inside the wafer switch wool multi did spiders I hope this is resurrected oh I'd like to see it play again just for the entertainment value of it been a bunch of hacks otters there this thing has really seen its share of time in the repair shop oh I see that looks like that was their wonder what happened I'm gonna see someone J hooked it in there's more hack to repairs right there more hacked repairs there more hacked repairs there maybe hack does not the right word I should just say repairs that almost looks like someone's done something with that whole tube socket all right since our since our low voltage rectifier tubes are missing anyway the 2 v u fours I put a test adapter in here I got this on voltage there's no reason why I can't apply power and we should just have filaments if the power transformers good by the looks of this thing it looks like somebody who kind of new TVs condemned it and put it out on the street because it wasn't working that's just kind of the feeling I get it doesn't look like it was working and it died and it was shoved out it looks like it failed and was looked at so anyway one Watts here we should have filaments only so let's see how do we nothing I this should be tuner this is function so nothing we have zero the power comes in here we have two paper bombs and then it looks like the airplane comes up to the power transformer right alright well I broke this wire off right here but I follow this down and it looks like it comes over here to the yoke socket so I must need to have the yoke plugged in there must be a safety loop here all right let's see what happens if I just bypass the yoke safety loop cut off I'm not it doesn't matter right now because I'm not I don't have any B+ because the rectifiers are missing so as the power transformer continues to self-destruct or I'm sorry maybe that's a vertical output transformer the power transformer is the big like 400 watt monster on top alright let's try this again with the yoke cutoff thing bypass here we go power there we go got some power flowing and we have filaments glowing so let's check our transformer secondary so I think it was 4 and 6 to 96 on 4 and to 95 on 6 so transformers good it's like we have 73.5 watts and just filaments I wonder if this is this the horizontal output right here so if we yank that out yep put it back in it's working so it looks like everybody's home here we have secondary high voltage or hello voltage for the B+ and we have filaments we have 68 watts and filaments power factor is 0.89 check this out this is the kind of stuff I see and I'm not really even sure what to think so this is the tuner right here the two tubes the RF and oscillator mixer tube and you can see that they originally had shields on them which are missing and they've been gone so long that the dust accumulation shows that they've been done a long time then you have this capacitor which has obviously been here forever because of the dust you can see that bodka solder there and then on this side right here it looks like it was never even soldered on it was just looped around so I see stuff like that and I'm not sure what to think this is probably not a really good resurrection candidate because it's got a lot of hacked repairs this - what was this thing recapped in the garage in like 1955 it could have been there's a lot of hack - repairs about all how about the stacker resistors here what's going on with this I don't think that's Factory the writers shows that capacitor right there so I don't know did they forget to solder it at the factory or did someone recap this thing so sleeping on this overnight thinking about this I believe the best way to go about resurrecting this is in a two-part video in this part will be the acquisition and the analysis which I've been doing which is this kind of looking it over and the radio I believe we can get the radio to work without powering up any of the high voltage deflection circuits so we can leave the yoke bypassed leave the CRT disconnected and just get the radio to work and that's what that's what I'm gonna do in this video I have photocopied all the schematics and I kind of understand now how the system works it's basically just a separate three tube am/fm tuner that injects its signal into the first audio amp so this right here the schematic which I hope this 6b a7 is good that's one complex - but that's both the AM and FM converter this schematic what you're looking at here is this tuner module and what it does is it just comes out and it injects into this tube right here the first audio tube the 6a v6 and you can see right there's the schematic for it just for safety I'm gonna pop that fuse out that's the like the damper plate voltage fuse to the horizontal circuit and I'll pop the 6j five vertical deflection tube out first thing I'm gonna do is I'm going to like have enough wd-40 here left a pretty sad situation just like that needs some medical help for sure I'm gonna hose down this mode switch this is the am/fm TV oh there we go now she's finally squirt and I'm gonna hose that down to get below the spider webs out work it back and forth a couple hundred thousand times it's all loose so this one is volume and tone we want to we want to lubricate that one and channelized dial look at how classy I'm gonna keep this brass plate this is really neat look at that easy vision lenses so all the way counterclockwise would be TV and then FM AM phone oh so we want to go all the way counterclockwise and then back one so we want to go all the way counterclockwise and then back one that should be FM that's FM AM phone oh and that's TV we want to fill these up remember this is ooh this thing is a resurrection which is just to make it work long enough to be entertaining that's nice we're not restoring this if we were restoring this if this was a high-value target I would be using my good control cleaner on it but since this is just a fix and dump I'm just using wd-40 on it why these controls are worn out look how much play is in that thing this thing has a lot of use on it I'm going to start by making a solid-state replacement 5u 4 out of this broken tube first thing I need to do is just gut it out because I just need the base to put some diodes in you can see how they parallel to 5u force here so what we're gonna do is we're gonna have two diodes going one going from 4 to 8 and the other going from 6 to 8 and you can see there and I marked them with yellow paint marker okay there it is and you can just google it I just use two diodes in series to get the PIV up a little bit and also increase the forward drop this will also be nice because this gives us easy above chassis access to test points here's our solid state 5u for replacement i guess we'll find out if I got that right here pretty quick these two five u fours are in parallel all we need to do is pop this into one I'm sure these diodes will handle much more than the five you for however the five you for is kind of a sacrificial item if you get a short if we have something short the five u4 l just blow apart inside with these it's gonna take the transformer out if it runs for any length of time so even that being a 400 watt transformer so probably want to use a bulb and I don't know about a very act I don't care about this thing that much to dig a very act out a little smoke never heard anybody 200 or 300 watt lamp I think this is a 300 and I simply put it in series with that yoke socket AC line bypass so basically this is in series with the AC line I pulled the rectifier back out sixty-six watts we're not going to damage anything with a 300 watt lamp and a 400 watt transformer or 300 that's a pretty big transformer that's the FM radio light if I click it back one that goes to TV which you can see there that works so we're definitely on FM that should be am and that should be phone out so we'll go to FM and here we go I got a speaker hooked up safety first right oh yeah getting dimmer dropping that would have to be capacitors reforming there's nothing else it's going to drop like that trying to hear if there's anything coming out of the speaker a slight hum this is the audio output tube right here well not much current draw not much wattage draw their eye unplug it seems to affect at about two watts that seems way too low wonder where the first just a six a v6 yes yeah I would have been real surprised if this worked and the am loop antenna is missing this is where the am loop antenna connected and was ripped out let's do some basic voltage checks here let's see what our 246 volts b-plus okay let's do some basic voltage checks here with the test adapter sorry I'm not using a tripod on this video so three and four should both be around 265 volts so three 217 but we still have our light bulb there and for 228 that's decent let's take a look at five it should be zero so let's see I've so tell us if our capacitor is leaky it's 0.6 it's a little leaky but not real bad and seven and I'm a 5 that's 8 let's try 8/8 our cathode which is 13 volts which is probably on the high side but again this capacitor here is probably a little leaky and because I'm getting a pop there I'm gonna assume the audio output transformers not bad so I should check what this tube is doing let me get a test adapter for it plates like 76 volts I wanted to check seven one and two oh I hear noise pin one is point three okay and two is gonna be ground so I heard a little noise when I touch there and no it wasn't the air pain yeah [Music] so it's definitely amplification well that's weird I'm getting a very low oscillation I'm smelling something burning which is kind of cool this is a little bit of a trip the wattage is just jumping all over the place something is shorting out it was just down to 112 and now it's back up to 134 and something is burning I smell something burning okay the burning smell stopped and something went open we're down to a hundred watts now which is barely above the filaments we now have three hundred and forty-three volts on the plate of the audio output we have zero on here so our hundred and forty volts went away and I wonder if one of these big can domes went open I you know like I said I smelled something and it wasn't something I'd smell it's not a common smell so where's this hundred and forty volts come from okay we got a funky voltage divider here which is probably these candle resistors yeah this one here had to go open we got 389 volts there and we have 0 volts there so this stupid thing must have gone open ok what we'll do is we'll just this big pot up to 1650 it's pretty close okay this is a hundred and forty volts and I think we got a bad capacitor that's shorting see what that's doing and that burning smell is back this is getting warm but not hot this is where I wish I had my Fleur because I could just look at this and see what was hot but it died and I'm waiting to see if they will warranty it it's almost worth just putting us on hold because that thing is a piece of diagnostic equipment is so effective so now we got 140 volts yeah we got a bad capacitor here hopefully it just kind of blows open and leaves us alone crap it looks like we got a broken wire right there that one's okay but this wire here is broken yeah the gloves will protect against 300 volts they won't protect against 4000 but they'll crack I'll pony mastercharge crap I see it it's arcing inside this if' can [Applause] I just saw it it was arcing right inside that I f kin it's silver mica disease and it's in this if' can of course it's not gonna do it now for the camera but I could see it right through that little hole right there so he definitely got silver mica dziena a disease and I wish you had been able to see that on camera let's see if we this looks like it's for the FM well there we go [Laughter] [Music] well it's receiving something that's sort of been resurrected so the silver mica disease in the am transformer there is so bad it blew the candle resistor out I guess it well it's a capacitor but not a capacitor like we think so where's the volume at though it should be a lot hotter than this [Applause] I got the party started why I do that it's got to be in this stupid can hear and that's shorted back out you should hear it carbon tracking I got the speaker dis disconnected and you can hear it popping [Applause] [Music] [Applause] [Music] [Laughter] [Music] so there's good sensitivity there's just not enough volume so you have something wrong up here in the audio stage it could be in the if2 then it try different vacuum bulb in there and that's not it reliable Selectron tubes kind of bargain basement job yeah that's gotta be for a em these have got to be the FM down here this is a no no but who cares it's a resurrection said it's going in the recycle bin I wish I could have caught that thing on camera arcing and smoking coming out of that little hole it'd be interesting to get a loop intent on this [Music] get a loop intent on this and see if it does anything you know if I put this on phone oh that's a phono input on the back right there [Music] seems like there's more than enough gain so I'm going to say that the the lack of volume here is due to the if' transformers how about if we borrow the antenna off this destroyed K part can't beat a little Zeppelin when you're working on an old arcing if' transformer Kaufmann console stereo it's getting KNX is that qualify as being alive on am hard to do one-handed [Applause] okay can't do a one-handed [Applause] [Applause] Hey announcement Aaron yeah it's working it's just no sensitivity because the if' transformers bad and that's probably not the right antenna it's probably close but not the right antenna yeah this is a typical case of silver mica disease which is where the capacitors that are integrated into the if' cans fail this is exactly what they do they are kin side they crackle and thunderstorm good thing is as it sounds like the TV tuner is working based on some channel get a little something scrub all these scrub all these off okay be nice to get channel six I clean [Applause] who knows what channel 6 is it is picking up channel 6 I think these Krusty I F transformers are arcing all the time I might have to get the to get the TV to work I might have to cut the power to this thing [Applause] very quiet but it is working so this right here t2 is a transformer that's arcing inside and I was thinking about I was considering pulling it out of there and opening it up and having a look but you can see it is really soldered in there I mean I can get it out and I might I'm thinking about it probably just go ahead and cut the take some pictures and cut everything away from it because it's charcoal filtered jewel biscuit all I can say is this was never designed to be serviced this was never designed to come apart let's get this open and see what it looks like so there are the mica capacitors right there in that plastic and that's right where it was arcing and you can see it's burnt right down in there Wow so it was arcing it was arcing across between the two mica capacitors I'm just gonna cut them out yeah just cut them all out with a pair of dikes they're gone that absolutely ruined it was that an F family that in it I think that's an a.m. I mean I did the quickest most botched job I could but all right well somehow in doing this maybe because I don't have the capacitors effect I probably do need the capacitors now that I think about it in order for the FM to work let me think about this for a minute okay I so this is I did this the wrong way what I should have done is I should have left the cores that screw I just screwed all the way in that's how far off my capacitors are if I had gotten the right value capacitors there would have been very little adjustment but you see I've driven that thing all the way in to compensate for having the wrong capacitors I should have put variable capacitors across the bottom adjusted the variable capacitors to peak it and then measured the variable capacitors and put fixed capacitors of that value in its place I have videos on the right way to do silver mica but I just stuck because this is just a resurrection I just stuck to 120 s there and you see how far off they were coming up in about 4 minutes it's 12:11 there's a I'm working recently peed the government by the way we're still on the light bulb through all of this using the light bulb is a safety in case something goes wrong [Laughter] so that's 1260 a.m. our music oldies station if it picks that up it's working decent on a.m. [Laughter] I bypass a light bulb which gives us a quite a bit more filament heat which cranks these old tubes up a little bit better gives them a little bit more so there's the am/fm let's see what the TV sounds like on Nash and do that I have all the tubes pull out I have a feeling we have silver my cadiz disease in the TVI f to hear the crackling okay that's the am/fm tuner resurrected on the Hoffman will do the television in part two it should be even more exciting so what happened here well the main thing was we had a broken wire down here we had silver mica disease in all of these cans but really bad in that one so I hollowed it out I put two 120 s which were the wrong value we could tell that by how far I had to crank that core in to compensate for it that thing arcing inside blew this candle resistor out right here I substituted in a big variable resistor in place of it so so far and we're hearing a little bit of channel 6 action on this over the air which is a good thing so in part two we'll try and get the TV working no promises there just look at all these capacitors yes it does need those capacitors across the a mif coil for the FM to work

Channel: shango066

Views: 79,318

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Id: 7vN_oYz9lm4

Length: 56min 22sec (3382 seconds)

Published: Mon Nov 25 2019