[Elecraft] K3 - External RX Mute

[Dave Hawes]

In the recent WAE CW Contest, we had two K3s on the same band, one as 
the live transmitter, and the other either tuning the band or listening on the 
running frequency to assist the run operator.

While listening on the run station's frequency, even though we used an Acom 
2S1 to ground the antenna line and thus protect the RX front end, the run 
station's signal was very loud in the spot radio's RX.

Is there a way to configure the K3 for variable muting during PTT active times 
on the other K3?  I'm wondering if the run station's PTT line could be used to 
variably mute the spot RX somehow.  Full muting is not the goal, but rather a 
way to keep the RX "on" but keep the S meter down to S9 or thereabouts, to 
allow the RX to recover very quickly.  Even with AGC-F, often the first 
character of the caller's callsign would be missed due to the recovery time.  
Plus it hurt my ears!

OTs may remember that the Collins 75S3B had a "Mute" jack on the back, to 
be used with the 32S3 transmitter.  In those days, we could accomplish a 
variable mute of the RX by putting a large resistance pot (50K maybe) across 
that jack, and switch it in and out with a reed relay following keying.  Can this 
be done with the K3?

73 - Dave N3RD