Hello Andy and all, I don't think NR must be a so good idea for digimodes. Because, it can be seen as non-linear filter. In that type of filter, the next sample is calculated, knowing the previous symbols and guessing what is the most probable symbol if nothing change (a sort of "no more set of information" condition)...
You are surely going to produce interference between symbols: the decoding will be not so good and the necessary synchronization will be more difficult because the difference between one symbol and the following will be reduced (i.e the difference between two successive symbols will be softened). But it would be interesting to experiment on calibrated signals and different speeds (from the PSKAM10 to ALE or PSK220F). 73 Patrick ----- Original Message ----- From: Andrew O'Brien To: digitalradio@yahoogroups.com Sent: Sunday, March 04, 2007 4:01 AM Subject: [digitalradio] Noise Reduction and the digital modes Noise reduction on my old rig never did much. Now I have a new rig the NR buttons actually appear to do some things. What about noise reduction and the digital modes, is it really helpful? I did just notice that with a Hell QSO NR made the print more blurred. For other modes I have not noticed much other than a lot less "speckles" in the waterfall. Maybe a graphically empty waterfall helps when a weak signal comes along but i worry the weak signal may get zapped by the NR. Comments ? -- Andy K3UK Skype Me : callto://andyobrien73 www.obriensweb.com
