[R-390] R-390A Break-in question

[Roy Morgan]

At 12:13 PM 8/16/2006, John Lawson wrote:
>...my Venerable Valiant,...I wired in a DowKey and used the contacts on it 
>to ground the break-in point on the 390A, as per the manual.... I still 
>have "leakage" into the radio -


John,

The break-in function in the R-390A does two things:

1) It grounds the audio at the output from the detector.

2) It switches the antenna relay to -  disconnect the antenna input from 
the jack and ground the jack.

This means that the entire radio is still working except for the antenna 
connection and the audio.

The Valiant puts out enough signal to get into the front end of your radio, 
and the detector puts out enough signal to get through to the audio section.

I suggest you try:

1) clean the contacts on the breakin relay (in the audio deck).
2) re-establish the ground that relay uses to short the audio signal to the 
chassis.
3) Add another relay in the system to ground the antenna line going to the 
radio
and if needed:
4) add some function to remove the IF stage from operation, such as 
applying some rather healthy (and maybe adjustable) bias to the AGC line.

Roy



- Roy Morgan, K1LKY since 1959 - Keep 'em Glowing!
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