Recent content by theta sigma

D77 was the culprit! Replaced it with a part from the junk radio and now I have full RX volume! All the other symptoms appear to have gone away as well, except for the S-Meter jumping up in PA mode. Not overly concerned with that as I don't ever use the PA function. Next project on...

Yes, the schematic on CB Tricks is confusing. On my board, TR30 is located where the PCB layout says TR39 should be. Either way, the voltages on this transistor are out of whack too. The base voltage on TR38 is very very close to TX voltage levels, so the radio is definitely trying to...

Getting close to solving this. Manually grounding the collector of TR38 brings back full RX volume. Now I just have to figure out where that stray voltage is coming from. Could TR38 be defective?

Getting some odd voltages on the collector of TX transistor TR38. The voltage chart show that this should be at 0 volts during RX. When I turn the radio on, there is somewhere around .8 volts on the collector of TR38, and it immediately starts climbing. The rate of voltage climb seems to be...

The radio is very old, probably close to 20 years. She's been sitting in storage for the last 10 years. I stopped talking on the radio for a while, but now have regained a passion for it. She's always been my favorite radio though and I'm determined to fix her. I'm not opposed to doing a...

C190 and C193 replaced. No effect, but I feel better now. :) No noticeable hum from a finger on pin 4 of the IC8, even when the volume is working normally for the first few seconds. Perhaps my fingers aren't compatible. :) C157, C156 replaced. No effect. TR41 was upgraded to a...

Forgot to mention that AM TX seems normal with normal modulation. The only TX issue is the USB squeal.

On the DX 77HML: The S-meter seems normal. The RX speaker volume is loud when you first turn the radio on after leaving it unplugged for a while. After a few seconds, the RX volume slowly drops to the point where you have to turn the volume control wide open just to hear anything. Once you...

My Galaxy DX 77HML has developed this same symptom. I realize this is an old thread, but was hoping someone might know what the issue is.