[Elecraft] K2 and FSK

[Ron D'Eau Claire]

Dick PA2DW wrote:

"...if the K2 could ever make real FSK, I would be very pleased! But it
would probably take a significant hardware modification and software
development for just a small group of people, so I guess that the developers
at Elecraft will probably think they have something better to do hi!
Or?!..."

--------------------------------

As I was answering Aki's question I was thinking that the K2 already does
"true" FSK, but not at data keying rates. The PLL local oscillator and BFO
frequencies are changed by the controller as needed to maintain the dial
accuracy when the sidetone pitch is change in the MENU. 

I'm not sure about the phase issues, but it had me wondering if it were
possible to provide an external keying input that would toggle between two
"sidetone" frequencies during transmit in CW mode. Perhaps just a tuning
input to the BFO would do the trick, since it's already a VCO and it is part
of the transmit signal chain. However, maintaining phase while changing
frequencies is a different story. 

For that, how about an external DDS with the necessary keying circuitry such
as you described used as an external transmit BFO for the K2?

Your observation about the relatively small number of users compared to the
whole K2 population out there is exactly why Wayne and Eric had always
encouraged experimentation with the Elecraft rigs, and even offer a helping
hand when they can.  

Ron AC7AC