[R-390] Low Audio

[Flowertime01 at wmconnect.com]

Fred Bray KE6CD

One of the audio problems with the R390 or R390A is in the wire harness 
shape. On some receivers the loop in the audio harness to audio deck is a bit long. 
Setting the deck on a surface will scrunch the wires in the harness a bit. 
Some times it will cause the wire harness plug to pull off the deck connector. 
Over time things break.

As many thing as you have had to try from the mail list here has not gotten 
the problem fixed. So its time to look into the audio deck wire harness back 
shell for a frayed wire.

I is right that the line audio and local audio should both die. There is only 
one detector, one limiter, and one audio amp V601 a 5814 in the audio deck. 
Then the audio comes through the deck plug J620 to P120 to the front panel. The 
audio is wired common going out on pin 2 of the plug to both the local and 
line gain pots. 

Check your diode load jumper on the back panel. This is the 1/2 way point 
between the detector and the audio deck.

With an AM station and no BFO you should see -4 to -10 volts on the diode 
load. 
With the BFO on a cal tone you should have over -20 volts on the diode load.

If you have it travel to the audio deck.

If you do not have it travel to the IF deck.

Why do you think you have an Audio Problem?

Just because you were working on the Audio pots when the receiver died may 
have nothing to do with your problem.

Hope this helps

Roger KC6TRU