Posts: 24
Threads: 1
Joined: Feb 2025
City: Sun Valley
State, Province, Country: Nevada
On K2, pins 1&2 are shorted. On K4, Pins 1&3 are shorted. Others are OK.
The voltages are the same except #4. I must have had the lead on the wrong pin. #4 is 0v.
#1891 is a bulb. There is one wire from the volume pot to the lamp. That wire is 12.2v.
I've been testing with chassis as ground.
Point 19 is definitely 12v. I must have messed something up before. All points except #4 are the same.
X3 and X6 are bad. X2 and X4 are good. X5 I haven't been able to test yet.
Posts: 16,339
Threads: 570
Joined: Oct 2011
City: Jackson
State, Province, Country: NJ
On K2, pins 1&2 are shorted. On K4, Pins 1&3 are shorted. Others are OK. - your 0.047 caps are fried in both
The voltages are the same except #4. I must have had the lead on the wrong pin. #4 is 0v. - better
#1891 is a bulb. There is one wire from the volume pot to the lamp. That wire is 12.2v. - OK, so it is just 12V to lamp. no effect on the rest of the circuitry.
I've been testing with chassis as ground.
Point 19 is definitely 12v. I must have messed something up before. All points except #4 are the same. - Like I said, it is wrong on many levels, and there are probably short and burns of parts.
X3 and X6 are bad. X2 and X4 are good. X5 I haven't been able to test yet. - It seems this radio had some major surge. Caps shorted, transistors burnt. Or someone tried to plug it into something that it shouldn't been plugged into. I am not sure what those K assemblies are. If they are potted circuits, you will need to somehow replace them. If resistors are good inside, you could try to hook up bad parts (caps) outside.
If you want to be a good sport and keep doing it, great. But it seems like you might have to replace half the parts.
Basically, from what I think might've happened to it, you need to check every single component.
If you do this, we could answer questions one by one as you go along.
PS. To my taste (and had I had that radio in front of me and all the parts available, I probably could fix it in a day or so), to me personally it would not be worth it and I would just toss it. If it has any special significance....sure.
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.
Posts: 24
Threads: 1
Joined: Feb 2025
City: Sun Valley
State, Province, Country: Nevada
Thank you. I have to take a break from it for about a week. I'll have to do some thinking. I was toying with the idea of making a PCB and populating it with available parts. Just not sure how I would connect the tuning circuit. I could remake the potted circuits, but I'm not sure I feel like it. I was thinking about maybe just trying to connect some good caps on the outside. Like I said, I'll have to decide. Parts are very hard to find. If I had all of the parts, I wouldn't hesitate to rebuild the whole thing, but that's not the case. Thanks for all the help. I'll let you know.
Posts: 24
Threads: 1
Joined: Feb 2025
City: Sun Valley
State, Province, Country: Nevada
Alrighty. I'm back. I'm not ready to give up. Suggestions on where to start?
Posts: 16,339
Threads: 570
Joined: Oct 2011
City: Jackson
State, Province, Country: NJ
See above.
Try to see about the shorted caps etc, remove the transistors, and do not populate them until you rectify the sub-assemblies situation. Make sure all caps are good, diodes etc. Resistors, of course.
Then you can proceed with the transistors, one-by-one, from the RF X1-X3(see if you could get the voltages more or less within the reasonable distance from those listed), and then to the audio and the audio-power ones, X4-X5, and only then X6.
Do not plug-unplug the speaker while hot. And when working with the X6 in-circuit, it is better if the speaker IS plugged in.
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.
Posts: 24
Threads: 1
Joined: Feb 2025
City: Sun Valley
State, Province, Country: Nevada
Thank you. I have one board completely de-populated. Just looking for the correct values. I'll let you know. Still having a bear of a time trying to find replacement germanium transistors.
Posts: 16,339
Threads: 570
Joined: Oct 2011
City: Jackson
State, Province, Country: NJ
If the small signal ones, take any Ge transistor with unity gain good enough and Vce max 30 or so V.
For the output....you could try whatever it is electrically good enough to verify radio's functionality and then dedicate your efforts to finding the proper replacement. They pop up on eBay.
Also, you could possibly look into some Russian or Eastern European old transistors, they do exist on eBay. Gosh knows, they might be physically compatible with your heatsink.
Like this one, is a 20V Hi-F (90MHz) PNP, small signal.
https://www.ebay.com/itm/185356831583?_s...R5jv4eqnZQ
From memory (I do not know if they would fit physically) the Ge output transistors are:
P201
P214
P215
Large power
P210
https://www.ebay.com/itm/355761097918?_s...R5i8qeunZQ
Not a very good transistor as the unity gain Frequency is low.
P214, a good transistor.
https://www.ebay.com/itm/283924385059?_s...R6jfsOunZQ
So is P215.
P201 not as good but likely would do.
https://www.ebay.com/itm/283888198612?_s...R7qc2uunZQ
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.
Posts: 16,339
Threads: 570
Joined: Oct 2011
City: Jackson
State, Province, Country: NJ
https://manuals.plus/m/a0e441e8a2d89c9a9...d7b0c9_pdf
This is the replacement guide for transistors by GE parts.
So, GE-3 is your power replacement for AR14
https://www.ebay.com/itm/204894362450
Just as an example: you probably could find cheaper ones.
AR103-105 are GE-1. Again, look for more.
https://www.ebay.com/itm/226561807385?_s...R-iog-6nZQ
AR107-108 are GE-10.
Can't find on eBay
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.
Users browsing this thread: 3 Guest(s)
|
Recent Posts
|
6TPZ and 5TPO Radio Help
|
This is the replacement guide for transistors by GE parts.
So, GE-3 is your power replacement for AR14
Just ...morzh — 04:57 PM |
Philco 91 Restore Code ??
|
How do I know if AVC is OK?
For the compensator cap I settled on 330pf. Its much closer now and close enough for me. I ...dconant — 04:46 PM |
6TPZ and 5TPO Radio Help
|
If the small signal ones, take any Ge transistor with unity gain good enough and Vce max 30 or so V.
For the output....y...morzh — 03:43 PM |
The list of my radio & TV collection!
|
Yes, Michael. This winter I repaired this Westinghouse, RCA 121 and Zenit 5S29. All that remains is to veneer the Zenit ...RadioSvit — 03:28 PM |
6TPZ and 5TPO Radio Help
|
Thank you. I have one board completely de-populated. Just looking for the correct values. I'll let you know. Still h...R3Sons — 03:13 PM |
The list of my radio & TV collection!
|
Is this the one from the Fall Kutztown 2023?morzh — 02:59 PM |
Philco 91 Restore Code ??
|
If it does not get narrower with strong signal and your AVC is OK, it could veru well be that the shadowgraph's magnet i...morzh — 02:58 PM |
Philco 91 Restore Code ??
|
The width does not get narrower with generator.
I think I will try some other cap values.dconant — 02:56 PM |
Philco 91 Restore Code ??
|
410pF is a large capacitance to parallel to a compensator.
As for the shadowmeter....yes, 3/8" is a bit wide, bu...morzh — 02:49 PM |
The list of my radio & TV collection!
|
My new nostalgic video...
My weekly video on radio history
Who is interested - come, watch, critically evaluate the qu...RadioSvit — 01:47 PM |
Who's Online
|
There are currently 3027 online users. [Complete List] » 1 Member(s) | 3026 Guest(s)
|
|
|

|