[Elecraft] Using the V6.2 lite Softrock Rx as a panadaptor with Elecraft K3

[Jerry Flanders]

As a panadaptor for my Elecraft K3, I have one of KB9YIG's 6.2 lite 
SR40 receivers with the special IF for the K3 (32764 KHz crystal). 
This gives the SR40 a LO freq of 8191, 24 Khz below the 8215 IF of 
the K3. I routinely watch a panorama of about +/- 12 Khz on the 
PowerSDR display (using 96 KHz samping). I was watching +/- 24 KHz 
initially but my power supply gave me a weak constant waterfall 
birdie that I haven't eliminated yet.

I also have one of Jack Smith's Z-10000U buffer amplifiers (Clifton 
Laboratories) running between the K3's KXV3 output and the SR40 for 
isolation. (I didn't test to see if the isolation is really needed - 
maybe not, since the LO is offset 24 KHz.)

The above combination is giving me the best panadaptor I have ever 
used, and I have been using them since Heathkit made one for the 
Heathkit SB303 in the early '70's. The current ICOM receivers have 
panadaptors, but the resolution is lacking. With KB9YIG's SR40 
rx  and PowerSDR, I can even identify the various signal types on 
sight. I am using the version of PowerSDR that has simultaneous 
waterfall and panorama.

I have PowerSDR calibrated so that the display gives an S9 reading 
when the K3 sees a 50uV S9 signal from my XG-2 generator. Sensitivity 
is amazing - I can see signals on the waterfall well down into the noise level.

As an indication of what is possible software-wise with the 
Panadaptor add-on, I am able to run PowerSDR and Skimmer (or Rocky, 
just as well) simultaneously here on a Sempron 2 GHz 1GB machine, 
along with Writelog with RTTYRITE in CW mode as well as CWGET all 
simultaneously. PSDR and Skimmer are both using the same two input 
channels of my Delta-44, and Skimmer sees the entire I/Q IF range, 
not just the audio. No audio routing tricks or "Y cables" are needed. 
The remainder are using the on-board VIA AC97 sound card. Total CPU 
usage ranges 50 - 70% with all running or around 20-40% with PowerSDR 
but without Skimmer/Rocky. The computer also generates CW and I have 
not seen any CW keying hiccups so far in limited S&P yesterday in the 
contest even at 70% CPU. This machine does not use on-board video, 
which might slow it further - it has a dual-monitor AGP video card.

This is a simple panadaptor setup - I view only and have no K3 
control or click tuning from PowerSDR or Rocky/Skimmer.

FYI, it is often possible to run multiple apps on the same sound card 
- I once had 8-10 copies of MMTTY running on a VIA AC97 on-board 
sound "card" under XP home as a test to see if multiple simultaneous 
RTTY profiles worked. Each copy only added about 2% to the CPU load.

Note: I understand KB9YIG has retired this particular kit, but a 
replacement may be available in the future (see softrock40 at yahoogroups.com ).

Jerry W4UK