Hello Alan, > I have been using WinRad with an RFSpace SDR-14 and an Icom 8500. > WinRad is a great piece of software. I've also tried SDRadio with the > SDR-14 using a two sound card set-up, to gain access to AM, FM and > ECSS modes. > > So my request is... could AM, FM and ECSS modes of SDRadio be added to > WinRad. This would enable SDR-14 users to have, the ultimate tool for > demodulation. You might be interested in trying linrad.exe with your SDR-14. Linrad for Windows can be downloaded here: http://www.sm5bsz.com/linuxdsp/linrad.htm (there are two mirrors) http://g7rau.demon.co.uk/sm5bsz/linuxdsp/linrad.htm http://nitehawk.com/sm5bsz/linuxdsp/linrad.htm
The file wlr2-xx.zip contains the latest version (currently xx=25) and the two text files errors.lir and help.lir. The zip file is 280 kilobytes, just unpack and execute linrad.exe logged to the directory where the .lir files reside. Linrad will create some par_xxx files to store the settings you choose in the same directory. To use Linrad to receive AM with a synchronous detector have a look here: http://www.sm5bsz.com/linuxdsp/run/am.htm Some info on using SDR-14 with Linrad is here: http://www.sm5bsz.com/linuxdsp/usage/sdr14-w/sdr14-vw.htm (the links are also on the corresponding places at the mirror sites) For Windows it might be a good idea to decimate by 432 to get an output sampling rate of 154 kHz. There are many ways of doing this in Linrad. You may set for example M_CIC2 [4] M_CIC5 [4] M_RCF [27] This will not give a particularly good filter for the output to the PC since only 1/27 of the bandwidth will be sent to the PC and therefore the shape factor of the output filter is degraded by a factor of 27. With a very low first decimation the spurs associated with the first data reduction step inside the SDR-14 (AD6620) is minimized. You may also set something like this M_CIC2 [12] M_CIC5 [18] M_RCF [2] It will give a better shape of the output filter but the number of possible spurs will be larger. In Linrad the compromises in setting the filters inside the AD6620 are left to the user because users having a preselector or converter in front of the SDR-14 should set M_CIC2 large since no signal at all will be present at large frequency separation. The subsequent down sampling stages will then provide better filters since they can use smaller resampling ratios. (There is a lot of detailed info in the AD6620 data sheet.) 73 Leif / SM5BSZ
