[Elecraft] VOX / PTT combination on k3

Richard Ferch ve3iay at storm.ca
Sat Dec 19 09:39:30 EST 2015


Once you have enabled VOX, you are stuck with whatever delay it imposes. 
In effect, the VOX and PTT functions are in a logical OR relationship - 
if either one of them wants the rig to be in transmit, it will be in 
transmit. In your current setup you could disable computer PTT control 
entirely and you would not see any difference.

There is a way to set the VOX delay to nearly zero, and that is to 
enable QSK. With PTT and QSK enabled, your computer messages will be 
controlled by PTT (no RX between characters), but your paddle-sent CW 
will be QSK. If you are using a non-QSK amplifier, this won't work for you.

Without using QSK, you can reduce the VOX delay in the K3, but if you 
are using an external amplifier that is not capable of QSK, the 
amplifier may impose a lower limit on the VOX delay you can safely use, 
i.e. you may want to have a VOX delay long enough to prevent returning 
to RX between characters, and maybe also between words, during paddle 
input, and that VOX delay will also affect the end of computer messages.

If you have an external keyer that has a PTT output, you can wire-OR the 
keyer's PTT output with the PTT signal from the computer. When the 
computer is sending, PTT will be asserted by the computer and there will 
be no RX during messages, but no delay in the return to RX at the end of 
the messages. When you are sending from the paddle, the delay will be 
controlled by the keyer's PTT settings. If you have a non-QSK amplifier 
you will have to configure the delay in the keyer to accommodate the 
amplifier, but the delay will only apply to paddle-sent CW, not to 
computer-sent messages.

73,
Rich VE3KI


S57AW wrote:

> Simple question... Is there a way to avoid VOX delay on CW mode when PTT is
> used?


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