Friday, December 11, 2009

SDR to WSPR from Ross T61AA

Old friend Ross, (who needs to start his own blog), sent me some progress notes on how he's going trying to combine a SoftRock with WSPR software. He writes:

"I have found that the SoftRocks are not very stable when left to themselves. I have attached a screen dump of WSPR and SpecJT and also the list of spots on the site. You will see that the received spots are a lot more stable than the off-air reception by SoftRock Xtall+USB V9.0 Rx. Next that I will do is find the Kuhne crystal ovens that I have somewhere in Kabul, when I am up there in a week or so and attach to the Si570 local oscillator to keep at a steady 40 deg C and see how that affects the stability.

At least though I have got WSPR working through the Virtual Audio Cable OK and managed decodes."

20m SoftRock test stability.JPG

Later:

"Have spent the entire night on 40m and, while the SDR is not as sensitive as the Icom, I have many spots on 40m overnight, including PY8ELO and an LX from South America. My fix for the drift will be a crystal heater such as Kuhne Electronics QH-40A - I have two sitting in my junk in Kabul and must find them. Next issue is to get a program that provides I and Q out for Txing on WSPR."

20m spots as on WSPR.org to compare with SoftRock.png

Ross tried various software to patch the audio but in the end:

"You know what, I had the solution already and did not see it because Rocky did not want to work with the el-cheapo USB sound card.

When I was home I found that WSPR just did not work properly with the in-built sound card in the MSI U100+ netbook that I got for WSPR and WSJT. I got a really cheap USB sound card and found that WSPR worked quite well with that. When I first tried Rocky the SDR prog I found that it did not like the el-cheapo USB but would only work with the in-built Realtek HD Soundcard and was stuffing around trying to get rid of all the associated drivers that did all the Dolby-surround and other tailoring on the sound - I wanted it barn-door-wide.

I also subsequently found a simpler SDR Rx prog called SDRadio by I2PHD which, strangely enough, will not work with the Realtek in-built but works fine with the el-cheapo USB - problem solved two USBs and an actaul hard cable cross-connected and Voila! Simple."

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