Andy, I also have a TS-2000. Are you using the Packet filter menu, 50A? This can set the bandwidth down to about 100Hz. The DSP on the TS-2000 is not the best but I find it quite effective most of the time. It does produce a lot of ghost signals and aliases. The 12-bit DSP probably limits the IF dynamic range to less than 70 dB. The TS-2000 also does not have the best front end dynamic range. It is very rare to find signals with more than 60 dB difference in signal strength in the passband so I find this adequate for almost all the operating I do. The notch filter also works quite well although I haven't used it on the TS-2000.
I also use an IC-735 with a 250Hz CW filter. Some modification was required to enable the CW filter in SSB mode. This doesn't have the problem of ghosts and aliases of the DSP filtering but it is a bit wider. For the best performance, the narrow filter has to be as close to the antenna input as possible in the circuit. A 100Hz wide roofing filter would do the job but I haven't heard of anybody installing one. Ed WB6YTE --- In digitalradio@yahoogroups.com, Andy obrien <k3uka...@...> wrote: > > From time to time we have had discussions here about the problem with > PSK (and other modes) when a strong stations appears to grab the > waterfall and wipe out all the other stations within a 2-3 Khz range. > Because of this phenomenon, when I purchased a new rig, I looked for > one that could have AGC totally off (when needed) and one that can > employ narrow DSP filtering. I must say that I have not really solved > this issue . I can see a marginal difference with AGC turned off but > strong signals still essentially desensitize other stations in the > waterfall. The DSP features do better and I can get rid of the > phenomena by turning to a narrow filter. However this does not help > if the offending station is with 300 - 500 Hz ( a lot when dealing > with narrow digital modes). > > Does anyone have any advice on how to once and for all solve this > issue? My rig is a TS2000 > > Andy K3UK >
