-Thanks, that is helpful. I will give it a try this weekend. Andy K3UK
-- In digitalradio@yahoogroups.com, "Vojtech Bubnik" <[EMAIL PROTECTED]> wrote: > > > If I wanted > > to compare WSPR, JT65A, and Olivia on a 30M frequency at a given > > power output will it do that ? > > You need to run the WSPR/JT65A or Olivia software on your PC in > parallel with pathsim. Digi software will produce sound to the sound > card, pathsim will sample from the sound card and produce wav file. > > All you need is some kind of loopback between sound output and input. > On my old laptop it was possible to setup the loopback on a single > sound card by windows mixer. You just have to select "recording from > sound output". On my new laptop this is not possible and I have to > connect earphone output to microphone input with a cable. There is > also a freeware "dummy" windows sound driver on internet, which > creates two interconnected virtual sound cards. The output of one is > routed into an input of the other. > > After you capture the processed wav file by pathsim, you just need to > play it back by any sound player and let the digi software run in > parallel with the same sound loopback in action. The digi software > will now listen to the distorted digital stream and try to decode. > > Pathsim will add configurable amount of noise to the signal. SNR is > calculated relatively to the signal RMS. One needs to consider crest > factor if he compares digital modes. But the modes you are interested > in have all crest factor 1 (not true for Olivia, but I believe its > crest factor is nearly 1 also). All three are single tone FSK mode. > > From the pathsim manual: > If the AWGN source is enabled then Gaussian white noise can be added > to the input signal in order to simulate various SNR ratios. An SNR of > 0 means that the input signal rms level is equal to the noise rms > level as measured through the 3KHz bandpass filter. > > 73, Vojtech OK1IAK >
