Mike (and others),
I have a Drake Tr4 transceiver and R4a receiver that I'm thinking of using 
in such a configuration.  It seems that there must be provision for 
(possibly) two cables between.  One to pass the antenna an one to mute the 
receiver.  As soon as I organize my shack, I'm gonna get serious about this 
thing.

Thanks.

The Other Howard, WA9RYF
----- Original Message ----- 
From: "Mike Duke, K5XU" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Wednesday, December 05, 2012 5:09 PM
Subject: Re: Older rigs with external receiver operation


> my FT-102 has a switch on the back labeled external receiver and my
> TS-940 had one as well.
>> Was the purpose of this to use the external receiver to listen,
>> while sharing a single antenna and when the controlling rig was
>> keyed, the external receiver muted?
> Michael, that's basically how it worked. Although I never used the
> external receiver option, my old Swan 500CX also had that capability.
>
> So did the Drake TR4.
>
>> Did you have to use 2 separate antennas as well in this kind of a
>> setup?
>
> No. You could do that if you wanted too, but you would then have to
> come up with a way to switch the second antenna to the external
> receiver, and remove that antenna during transmit. That could easily
> be done with the proper relays or electronic switch, but most people I
> knew just used one antenna.
>
> Some rigs only provided the contacts to power an external relay that
> could be added for that purpose, much like the switching relay for an
> amplifier.
>
> People would often use a separate receiver rather than buy an external
> VFO, especially if they already owned a decent receiver.