PSK31 Progress

I've made the move to USB -- I had an M-Audio JamLab USB I/O sitting around picked it up a few years ago to patch my guitar into Garage Band. I hadn't thought about using it for PSK31 audio until now. Downloaded latest XP driver, switched the cables over to it and saw improved results immediately -- now the waterfall shows a much cleaner signal than I was getting when running the RX audio directly into the soundcard, confirming my suspicion that my soundcard is crap and a dedicated USB I/O device -- even a cheapo single-channel box like the JamLab -- would greatly improve things. My inner geek is smiling.

The JamLab appears to be replaced by the Transit Hi-Resolution Mobile USB Audio Interface, apparently the same device with a new label.

I'm a little concerned with the range of level adjustment -- with the control panel and K3 output levels set at 100%, I'm getting about 20-25% input level in DM780. It seems to be enough, though. Also have to up the K3's Line In gain to 30 (up from around 8) in order to tickle the ALC to 4 bars as suggested by others on the Elecraft reflector.

Still getting noise from the outside world, not sure what to do about that. It seems to be intermittent and shows up on the waterfall as two fairly broad (300 Hz) stripes centered around 1325Hz and 1950Hz when tuned to 14070.0 kHz. They are weak enough that they disappear when a strong signal appears in the passband and the AGC drops the gain, but if a weak signal is anywhere near the noise it's tough to pull them out.


I've been considering the MFJ-1025 phasing noise filter with an outdoor sensing antenna; not cheap ($180) and not sure it will help on this particular noise source but MFJ's 30-day return policy makes it worth a try.

After running the K3 wide open for a few days I now find myself crunching down the bandwidth of the K3 to a narrow (200 Hz) passband and centering it on the desired signal in order to reject adjacent strong signals and improve copy of weak signals. The K3's combination of 8-pole 400Hz roofing and DSP bandwidth filters are simply awesome for picking a single signal out of a crowded band.


By keeping Filter Preset I set wide open (4.0 kHz in DATA A mode) and Filter Preset II set to 200 Hz, I can jump to the narrow setting quickly when I spot something on the waterfall and shift the passband until it's centered on the signal. It would be cooler than penguin turds if DM780/HRD would set the K3 width and shift automatically to zero in on an incoming signal with the click of a button, but since this isn't a K3-specific program I'm not hopeful this will ever work it's way into a future version.

So now just barely 4 days into PSK31, and with little effort, I've worked 7 DXCC entities (8, if you count the USA, which I don't...):

• CO - Cuba
• FK - New Caledonia
• KH6 - Hawaii
• SP - Poland
• TG - Guatemala
• UT - Ukraine
• VE - Canada

Moving along...