On Thu, Feb 26, 2009 at 2:37 AM, Art McBride kc6uqh@cox.net wrote:
Henk, I would suggest FM 2.4 KHz deviation. You will need a Gaussian filter after the 4800 baud digital to make the logic transitions raised Cosine. The FM modulation needs to be direct coupled not AC coupled. Never Had a TS 2000X still using a ICom 820 disaster!
GMSK provide for a modulation index of 0.5 making its performance a little worse than AM in performance. Works O K on strong signals, looses it on noise, multipath, or interference. There is no capture effect that is normally associated with FM and modulation indexes greater than 1 Good luck, Art, KC6UQH
A follow-on question, if nobody minds.
I've recently bought a Delta-44 soundcard to do some higher definition SDR work. It looks like the softrock line of radios, for instance, will have a 2m version fairly soon. http://www.w9idx.com/node/42
What program is state-of-the-art when it comes to digital modes and SDR work? Or even when it comes to FM audio out, is there a 9600 baud software sound modem that equals or outperforms a dedicated modem?