Galaxy DX-55V & Saturn

[Cable Guy]

Hawkeye, replace both driver and final, even if they check out. I did that with this 66v and she came back to life. Both check okay on the tester, although both had very low gain. Also, a previous stages was mistuned.

 

[Hawkeye351]

Awesome, I'll try that out. Thank you Cable Guy.

 

[brandon7861]

Got another 55v waiting for me to find out what's up with it.

Symptom:
Turn power on and radio automatically keys up in transmit mode. Press the PTT and it doesn't change, it stays keyed up.

Mic op amp was showing strange numbers all the way around. Replaced with a new JRC 4558D, still same results.

TR32 was showing 8v on collector in transmit mode. Replaced tantalum cap at TR32 limiter, same results. Then replaced TR32, same results.

Collector of AF regulator and collector of Passthrough regulator shows as they should.

This radio did key up and talk good until I replaced R174 and R187. They were replaced previously with 2.2k ohm (way to low for my liking). Factory is usually 10k ohm in those two locations but a lot of people will replace those two with a lower value for more drive to the mic amp, but my opinion is 2.2k is way too much of a drop. If I need to replace those two from their factory values of 10k each, then I usually go with half of what the factory has in it, which would be 5.1k. This value seems to work best on these exports radios if the need for more mic drive comes up.

Anyway, I replaced those 2.2k resistors at R174 and R187 with 5.1k resistors. After that, then is when the automatic key up when turning power on started. After checking over a few things I noticed I had shorted out R187 to the emitter of TR33, and R174 (from collector of TR32) shorted out with the path that leads to the emitter of TR33 also.

It transmits a carrier fine, good strong carrier, just all the time is the issue. Won't unkey, even with no mic hooked up, just turn the radio on and it keys up by itself.

This thang drove me nuts, so I put it on the side for now.

Yes, it was my bad...lol...
I did this work at someone else's house, wasn't equipped and lighting wasn't as much as I am used to working with.

Even the best make mistakes at times...

When you are ready to come back to this one, I have the TX/RX switching drawn out on a separate page so it's easier to understand.

I seriously doubt shorting TR32's collector to TR33's emitter (ground) would hurt TR32. It is fairly well protected by the surrounding resistors. Just clear the short, inspect for other solder blobs that may have got away from you, then we can start checking voltage levels.