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The sch is dismal, nothing can be discerned.
http://www.nostalgiaair.org/Resources/684/M0015684.htm
The wires going to CG's of the tubes are rubber-coated and had to go.
A long wire was hanging....I cigured it is the 77s grid going to the tuning cap....indeer one of the cap's lugs had solder on it and a hole half open. Also rubber coated.
Looking at the sch.....it is a TRF. 3-tube at that, 2 RF stages and the audio amp. Did not know AC /DC TRFs existed.
Now off to recap.
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
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(04-12-2016, 09:56 PM)morzh Wrote: The sch is dismal, nothing can be discerned.
http://www.nostalgiaair.org/Resources/684/M0015684.htm
The wires going to CG's of the tubes are rubber-coated and had to go.
A long wire was hanging....I cigured it is the 77s grid going to the tuning cap....indeer one of the cap's lugs had solder on it and a hole half open. Also rubber coated.
Looking at the sch.....it is a TRF. 3-tube at that, 2 RF stages and the audio amp. Did not know AC /DC TRFs existed.
Now off to recap.
Mike;
There are lots of AC/DC TRF circuit sets around, but I'm surprised that RCA would build and or market such a thing since they owned the superheterodyne patents. Most of the ones I have seen were cut rate off brand sets, like the ones the infamous "Plant A" used to churn out, as well as U.S Simplex. The original Transitone model TH-1 from 1939 was a TRF AC/DC set, which was built by U.S Simplex, for Philco, but unlike this RCA it was not a Philco designed set.
Regards
Arran
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?
What radio is this? I dont remember it, lol
Picture please..
Confused me 
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The one you did not recap, with huge capacitors and wirewound ballast, from the same box as the DELCO, where I borrowed the 25Z5 from (which also turned out to be defective).
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come on mike
show some pic`s don`t be lazy 
Mr. non flipper
Some day, and that day may never come, I will call upon you to do a service for me. But until that day, accept this justice as a gift
mafiamen2
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I would show lots of pics but this takes me: 1) taking pictures, 2) going to Photoshop and compress them to 1024 pixel size, 3) uploading.
if I could just snap it with my tablet and put it right from there it'd be nice but the resolution is higher then allowed here.
So....will have to wait.
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It's got only one rf stage the second one is the detector and a 38 tube for the output. I think I almost started to fix that one when I was up at Kirk's last summer. I think didn't have the tubes for it at that time.
Terry
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Well it is plate detector so it is after all an amp, class B I think.. But yes, you are right, RF, plate detector and audio plus voltage doubling rectifier.
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The dual and triple axial electrolytic caps are a real bear to restuff...plus there are convenient ways to hook up individual caps so I gave up and just went for that.
No values written, just the Srague part number, tried to look it up, no references. So trying to go by the sch but as mentioned before it is unreadable and this is an understatement.
Swapped one dual cap so far.
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
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Hey morzh, I have the original RCA service manual and the schematic is very small like on NA but I can read all of the values. If you like I could scan and email a copy to you.
Let me know
Gregb
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No no Greg
Mike likes the torturer
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mafiamen2
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Ah one of those, LOL
Gregb
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Greg
I would appreciate it indeed, the masochist I am though, I could use a clear sch, I am sure I can succeed with what I have (since this radio was messed up with minimally by you know whom) but a clear schematic is always a big help.
I will send you a private message.
thanks!
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
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Kirk says it is a GE though it is RCA. Go figure them relabellers.
Thank to Greg I have a good readable sch, that helped a bit.
I finished recapping, fixed faulty wiring.....the AC/DC switch did not wirk, had to short it.
Also power switch did not work, and the potentiometer is weird, no tabs but a flange all around that hokds it. Ling story short when I opened it the rheostat fell out in pieces. Found a Philco pot clise enough. Though it is a bit deeper - was touching the 38 tube so had to bend some leads.
Anyways, I powered it up and it receives across the dial. Tomorrow will attempt alignment, as usual no dial, will have to guess the frequencies or use the local station.
Took me 3 evenings, maybe 7 hrs altogether.
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Noticed: the cap from Common to Chassis, 0.05uF, C5 shown under the tuning cap, not only absent but the chassis has no lugs or any provision whatsoever to solder to.
Also I am not sure what value the volume pot was, shown I think is 200kOhms but it is I think too much.
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
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