11-19-2013, 09:33 PM
Well one of the oscillator coils was bad in a 37-690 I have, so, a few weeks back I was bored and decided to dissect and repair the RF sub-chassis. I know, I know, some of you think a hole in your head would be better. Well I must say it was not as bad as I thought, considering this is the first one I have ever taken totally down before. Maybe ignorance is bliss!
I decided while I had the RF chassis out to replace all resistors out of spec, and replace any other caps missed from a previous repairman’s attempt. The RF chassis was really dirty with a lot of grease and grim all over down in the bowels of the contact switches. Since I plan to use this daily, I decide a good cleaning was in order. So I took each section completely down, cleaned and reassembled it. I mean I had already removed the RF Chassis so why not.
Well I did each section. Testing the coils and contacts as I went, I found the offending oscillator coil and replaced it with a good one from a 37-116 parts chassis I have laying around. The oscillator coil suffered from the dreaded green wire disease, maybe someday I may try to fix or rewind it, when I get real bored.
After I got the RF Chassis all back together, tested each stage with a signal generator and tracer, found a couple of miss wired coils on my part. I decided to see if I had ruined my radio forever. Well it works, and works well. I will put it back together; check out the rest of the chassis and power chassis. Repair the clarifiers and call this one good.
I figure a picture of how I tested the RF Chassis would show how crazy I am.
Enjoy
I decided while I had the RF chassis out to replace all resistors out of spec, and replace any other caps missed from a previous repairman’s attempt. The RF chassis was really dirty with a lot of grease and grim all over down in the bowels of the contact switches. Since I plan to use this daily, I decide a good cleaning was in order. So I took each section completely down, cleaned and reassembled it. I mean I had already removed the RF Chassis so why not.
Well I did each section. Testing the coils and contacts as I went, I found the offending oscillator coil and replaced it with a good one from a 37-116 parts chassis I have laying around. The oscillator coil suffered from the dreaded green wire disease, maybe someday I may try to fix or rewind it, when I get real bored.
After I got the RF Chassis all back together, tested each stage with a signal generator and tracer, found a couple of miss wired coils on my part. I decided to see if I had ruined my radio forever. Well it works, and works well. I will put it back together; check out the rest of the chassis and power chassis. Repair the clarifiers and call this one good.
I figure a picture of how I tested the RF Chassis would show how crazy I am.
Enjoy
