After a lot of procrastination, the dormant Softrock v6.2 project became timely. The job was to convert a Softrock v6.2 from its intended IF usage(IF 9.001?) to something a wee more interesting fer the KazShack main op, namely a 40m Softrock v6.2. The WB5RVZ pages are the place to go for build information. A fabulous job of documentation on the many SR permutations.
Turns out, the conversion was fairly simple. As built, there were only 2 component changes, add the RX enable jumper, and add a wire for the second “ring” line output. Oh….also change the crystal. A few resistance and then voltage checks. Use the K2 as frequency meter to check the crystal oscillator frequency, and its F/4 from the divider. (28.220 and 7.055+/-).
Fired off “Rocky”, VE3NEA’s SDR program. Putz around with the settings for Rocky and the sound card….Success! Sweet.
Now the question…….What the heck is this transient!!???!!
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So…..the project is not quite complete. There are two full ready to build kits waiting on the sidelines (hat tip to AE5X for noting the availability). Still need to find a suitable enclosure. It also seems like inserting isolation transformers in the line-outs will be worth the time, and maybe the cost. A search on the radio shack site comes up empty for their audio iso xfmr. Mouser or Digikey.
Job one is a nice shielded enclosure, although there are lots of warnings about being wary of creating ground loops. Probably put an isolation transformer and front end protector on the inputs. Separate power source for the SR, and isolation transformer on the lineouts(insulated) to the sound card. Perhaps extra bypass caps on the power supply.
After that is done, maybe the transients will be reduced or eliminated.
Running Rocky on a dual core Pentium D causes the CPU to sometimes spike as high as 7%. Moving the mouse causes more CPU stress than the SDR software causes. Interesting.
Gonna be a lot of fun with this toy. 🙂
Many thanks to W3DQ for the original project package.
The show-stopper for me and SDR is the lack of a stereo input on the sound card of either computers. Are you using an external or internal card with your set-up?
It is an internal card. Amazon had the ASUS Xonar DG on sale, and Xonar had a 10 buck rebate, so the upgrade card was 18 bucks. It comes in both PCI(Xonar DG) and PCI-Express(Xonar DGX). The more expensive ASUS cards can sample 192 khz, but the one I bought gives me 96Khz. Outboard cards are more pricy.
The card gets good reviews from audio geeks, and I agree – much better sounding than the on-board sound.
Probably more about that in the next post……
Xonar DG only 24 bux at new egg…..20 bux after factoring in rebate and 5 bux shipping. They must be dumping the PCI bus version, cuz the DGX is still 45 bux.
http://www.newegg.com/Product/Product.aspx?Item=N82E16829132020
Next experiment is to see if the sound card driver is smart enough to co-exist with siblings of its own model.