[Elecraft] K2 & PSK-31

[Rod N0RC]

> Rod,

> I take it you don't have the KIO2 installed, nor the updated
> firmware? Otherwise I'd enable the RTTY mode, which allows you
> to set up separate  narrow filters optimised for data, and also
> disables the compressor. 

I do not have the KIO2, I do have the updated FW. I want to use
narrow filters. I like the wide waterfall of digipan.

> If you are forced to use USB or LSB, then you want to disable
> compression

Why? It seems to work just fine. Like I said I'm getting good on
air results. KSB2 manual says 2:1 compression is OK to use.



> (SSBC). The SSBA setting can stay the same is it usually is:
> the trick is  to make the attenuator in the cable from the
> computer to the mic socket so that it generates about the same
> level of audio as your microphone, then

I'm using the cable as described in the Digipan Help files. It
works fine. The cable plus the sound card control enable me to
set the audio just fine. The issue is setting it with a tracking
ALC, In my 746, using the exact same cable, I can vary power
output evenly from 0 to Max_Pout_setting. From the KSB2 manual:

"Tracking ALC: SSB transceivers use Automatic Level Control (ALC)
to reduce transmit drive if output exceeds a desired level. Many
transceivers require that you adjust the mic gain manually until
the ALC indication is in a certain range. The K2's ALC is
different: the drive level is automatically adjusted, over time,
to keep ALC close to the optimal level. This tracking ALC (TALC)
eliminates the need to adjust mic gain in most cases. You can
set the POWER control, mic gain, or speech compression to any
level, and the ALC level will average between 1 and 3 bars (in
ALC meter mode) as you talk."

So it stand to reason that if 1-3 bars is good for voice, it
should work just fine for PSK-31.



> Unfortunately, I don't think it is possible to use VOX to
> control the TX/RX  switching in the K2. In my experience, the
> K2 VOX is too insensitive, with

Works fine at the 0.4 setting,



> There's really no  excuse for not using DTR or RTS to control
> the PTT, as the circuit only involves one resistor, one
> general purpose diode and one general purpose

Many new laptops don't have a serial interface, mine is one of them. I
use VOX on my Icom 746pro, I also used a homebrew VOX circuit on a
PSK-20. Now with the K2, never a problem, works great.

73, Rod N0RC
Elecraft CC: 0 of 100, started 05-Jan-2003