[Elecraft] K3 - Using MiC Key (PTT) to Transmit (activate) VOX (NOT Computer)

[Don Wilhelm]

An alternative if one is using an electret microphone is *not* to apply 
bias from the K3, but to bias the microphone from a 10k resistor fed 
from mic jack pin 6 (to mic jack pin 1).  Put a relay in series with the 
resistor and operate that relay from the foot switch.
The microphone will not respond until the relay closes.
The footswitch would *not* connect to the K3 PTT IN.

This is not normal operation, and the original poster is asking for a 
new function from Elecraft.  I don't think many hams would take 
advantage of a function like that (at least I would not), so the most 
expedient way to implement it is by use of some external device (you can 
have the function now rather than waiting for Elecraft to develop it).

Some microphones already have a section of the internal PTT switch wired 
in series with the mic element, and those could be easily modified by 
disconnecting the PTT function connection to mic plug pin 2 and running 
the K3 in VOX.  In other words, the mic PTT switch closes the AF line 
between the mic element and the plug, so VOX will only work when the PTT 
switch is closed.

73,
Don W3FPR

On 8/15/2014 1:33 PM, iain macdonnell - N6ML wrote:
> I think it's an interesting idea. It seems it should be feasible to
> implement in firmware, but maybe non-trivial.
>
> Thinking outside the box; what if you route the mic signal through the
> footswitch instead of PTT? Or maybe through a relay that the
> footswitch triggers... and keep VOX on all the time.
>
>