Ge 10t1 - Videokarma.org TV - Video

bigaudioal · #1 07-14-2014, 01:34 PM

Going to start the recap of a GE 10T1 this week. I have never replaced seleniums with diodes and dropping resistors before. Does anyone know which diodes and resistors to use to replace the two seleniums in the GE 10T1 chassis?

Now more importantly, if you do know which diodes and resistors to use in series for each of the two seleniums in this set, can you explain HOW you chose these exact diodes and resistor combinations?

Thx.

Tom Albrecht · #2 07-14-2014, 03:13 PM

Hi Al,

I put together a list of restoration tips for GE Locomotives a while back, which you can find here: http://www.radiomuseum.org/forum/gen...tion_tips.html

It includes specific recommendations for replacing the selenium rectifiers.

Tom

bigaudioal · #3 07-15-2014, 06:21 AM

Thanks Tom! Will check it out.

bigaudioal · #4 07-15-2014, 06:34 AM

Great tips Tom! So it looks as though i replace each selenium with a 1N4007 diode and then to bring the B+ back down I am only replacing the existing 4.6 ohm resistor with a 20 ohm/10 watter? This 1 resistor adequately handles both diodes in this circuit?

Thx.

bigaudioal · #5 07-15-2014, 06:38 AM

Got some bypass caps done last night. Thought the side "board" mounted caps would be easier than most. Turns out they were kind of difficult. It's cramped in this little set.

Jon F · #6 07-15-2014, 10:24 AM

Check out my 800D restore. I finally got my last issue figured out, I'll post it later, but you can see in process pics

http://www.videokarma.org/showthread.php?t=260530

Tom Albrecht · #7 07-15-2014, 03:26 PM

Quote:

Originally Posted by bigaudioal

Great tips Tom! So it looks as though i replace each selenium with a 1N4007 diode and then to bring the B+ back down I am only replacing the existing 4.6 ohm resistor with a 20 ohm/10 watter? This 1 resistor adequately handles both diodes in this circuit?

Thx.

Yes, that's correct.

Tom

bigaudioal · #8 07-18-2014, 07:44 PM

Thanks. I ordered 1N4007 diodes from Allied. Searched for that numbered and ordered them. They arrived today and I was very surprised on how small they are. Did I order the correct ones? See below photo. That is my index finger next to one.

The label also has these specs:

1 A (max.) @25C IF; 1.1 V (MAX.) @ 25C; 5 UADC (MAX.) @ 25C I

Are these correct??

Thx.

Phil Nelson · #9 07-18-2014, 08:18 PM

Yes, 1N4007 diodes are tiny. The light band marks the positive (+) end.

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

bigaudioal · #10 07-18-2014, 08:21 PM

Thanks for confirming! Since I have not ordered before, wanted to make sure I got the correct part. Really appreciate it.