[Premium-Rx] Re: 6790 muting

[wglevy]

Dan

I have just spent the morning looking at the RA1792 circuitry and comparing
it to the 6790. On th A4 Main Board U4 on the RA1792 has a transistor switch
tied to the MUTE line which activates U4 pin 2 (Q1) and there is no
circuitry as you point out doing anything like it on the RA6790.

Also common to both radios there is a mute line in the RF preamp common to
both radios which disconnects the antenna input.

So a little experimentation is in order. I will ground that un used pin on
U4 today and see what happens. If it works there will be no need worry about
firmware. I plan like you to let hardware do the work.

73, Bill


----- Original Message ----- 
From: "Dan Rae" <rae4 at ix.netcom.com>
To: <premium-rx at ml.skirrow.org>; <levyfiles at att.net>
Sent: Friday, May 28, 2004 8:00 PM
Subject: 6790 muting


> Bill, the easiest way to do this is to fit a relay to short out the
> input and disconnect from the antenna socket.  I have done this.
>
> Unfortunately there is no way to implement  the full muting that the
> sister radio the RA1792 has, even though the PC wiring for the
> components to do this is present but unpopulated on the 6790/GM A4 IF
> board, you'd  need the appropriate firmware, and I've never been able to
> find this.
>
> I made up a little RF relay in a Pomona box with a male and female BNC
> that sits on the inside of the antennna connector.
> 73
> Dan
> ac6ao / g3ncr
>
>
>