Galaxy DX 73V

[Hawkeye351]

This one is a little more on the lighter side.

Galaxy DX 73V
Issues when came in:

1. Meter stuck
2. Continuous talkback (always on)
3. Distorted xmit audio

Upon evaluation:
Variable resistor tied off to a polyester cap. VR coming from audio IC, polyester cap tapped in around mic op amp.

R249 snipped

AM Power VR cranked wide open (keying 10w on a single 1969).

Frequency off.

Should be quick and simple...

 

[Hawkeye351]

Hmmm, why someone would yank out the 1k variable resistor on the bottom of the board (R212) and place a fixed 1k resistor in its place has got me.

Finished, working great...

Now back to the old school Ranger 2900 restoration.

 

[Hawkeye351]

Got this 73v back on the desk.
Owner stated the talkback is still in it.

Hooked it up, turned it on, let it warm up 15 minutes, keyed up, sure enough the talkback is still present, more like a feedback squeal.

Removed wire from J15, still feedback.
Doesn't matter if echo is on or not, still has feedback.

Removed mic plug pc board, visually everything looks fine. How would I test these 2 chokes on this mic plug board? The ground tab is still firmly soldered.

He tried 2 different mics, as did I, still feedback.

Tried external speaker, still feedback.
Any ideas?

 

[Hawkeye351]

Update:

The choke on the back of the mic plug board was cooked. Replaced it, now there is no talkback (feedback) whatsoever in this radio.

 

[AK321]

I just picked one up, in near mint condition. No issues at all, works great. It's doing 26W, that might be a bit too much for the final though.

 

[Eldorado828]

I just picked one up, in near mint condition. No issues at all, works great. It's doing 26W, that might be a bit too much for the final though.

That's a nice little gem right there. There isn't many of those floating around these days and especially in that shape.

 

[AK321]

Thanks! I bought one of these brand new 30 years ago, and loved it! The RK56 mic that came with it, is perfect for that radio. Super loud audio. Not bad for an old Galaxy!