[Elecraft] Two K2... One Mic... Zéro Problem ? :-)

[Nick Waterman]

JEAN-FRANCOIS MENARD wrote:
> OK Don, thanks for ideas...
> 
> I'm looking the ability to receive from both K2 at the same time. But
> when one K2 is TX, the receiving K2 will be off automaticaly (antenna
> momentary disconnected). When TX finished, both should receive again.
> The only manual operation I see is when I want to choose from wich
> one I would like to TX with. The antenna switching technic, with
> relay I guess, must be automatic.

I'd be tempted to do it in software on a PIC16F84 or similar. You could 
have 2 PTTs if you want, or one single PTT and a rig selector switch. In 
any case, you want 2 PTT inputs, 2 PTT outputs, 2 ANT relays, and then 
your code goes something like this:

# setup

5 connect both ANTs

# main "waiting to TX" loop
10 if PTT1 pressed then goto 100
20 wait a few ms
30 if PTT2 pressed then goto 200
40 wait a few ms
50 goto 10

# TX on RIG1:
100 disconnect ANT2
110 wait a few ms for relay to bounce
120 PTTOUT1 on
130 wait a few ms
140 if PTT1 still pressed then goto 130
150 PTTOUT1 off
160 wait a few ms for rig to stop transmitting
170 connect both ANTs
180 goto 10

# TX on RIG2:
200 similar to 100...180

1 PIC (assuming you're able to program them), couple of relays, clock RC 
or crystal, few other bits and bobs.

-- 
"Nosey" Nick Waterman, Senior Sysadmin.
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