On another reflector, Jonathan Naylor G4KLX talks about his D-Star Client software which is a soundcard program to operate D-Star through an analog radio. Since the fancier soundcards and even USB fobs typically have extra circuitry that ends up filtering the lowest audio frequencies that are used by gmsk, he recommends getting the cheapest and simplest USB sound fob you can find. His own fob was purchased on eBay for 1 pound.
I suspect the various digital modes have different audio requirements, and the gmsk requirement represents one extreme. Perhaps some of the very weak signal modes require a sound device with minimal distortion and may represent the other extreme. Jim - K6JM ----- Original Message ----- From: g4ilo To: [email protected] Sent: Saturday, August 14, 2010 6:57 AM Subject: [digitalradio] Re: Good USB sound card ? I had one that looks exactly like that though it was sold under another name, and I could not decode 300baud packet at all with it. When used to play back recordings of very weak EME CW all I could hear was band noise. I did try it on my Echolink node for a bit with no apparent problems. So my opinion is that while these cheap USB sound devices may work fine for normal computer audio they are not a good idea at all for digital modes. You may not even realize why it isn't working, or what weak signals you are missing. Julian, G4ILO --- In [email protected], Rik van Riel <r...@...> wrote: > > The Asterisk (VOIP) people have even written up instructions > on how to create a PTT circuit with this device. However, > I am just using the radio's VOX mode for now :) >
