[Milsurplus] scr-287 integration question

[WA5CAB at cs.com]

Jack,

I don't know whether it is a "design feature" or not but I once spent two 
days trouble shooting a deaf TCS receiver on the bench.  Only to finally realize 
that as I didn't have a transmitter plugged into the power supply, I had 
forgotten to jumper the screen lines that go through NC contacts on one of the 
relays in the transmitter.  Receiver worked fine.  Just took IF level output from 
the sig gen to get a signal through it.  So what you are experiencing is what 
I would expect if the audio lines aren't also shorted.

In a message dated 8/19/2006 10:58:41 PM Central Daylight Time, 
scr287 at sbcglobal.net writes: 
> One of the projects lately is putting together
> an SCR-287. I'm connecting a BC-375E and BC-348R
> together through a terminal box, and bringing audio
> to a BC-1366 jack box. Ultimate goal is an operating
> radio op position, with SCR-269, SCR-274N, and RC-36
> interphone.
> 
> Almost everything works as it should, but I have one
> problem I wonder if anybody has seen.
> 
> The '375 mutes the '348 by opening a set of
> normally closed contacts, this takes screen voltage
> off the the IF and one of the RF amps in the receiver.
> 
> Mine does this, but the receiver still operates well enough
> to hear the transmitter. Even with the antenna leads
> disconnected from the receiver. It is not grid rectification
> or audio coming in the power socket, as it is tunable.
> 
> Just wondering if this is a design feature to provide side tone,
> or do I have some other issue?
> 

Robert & Susan Downs - Houston
<http://www.wa5cab.com> (Web Store)
MVPA 9480
<wa5cab at cs.com> (Primary email)
<wa5cab at houston.rr.com> (Backup email)