Hi Dave, Yes, the narrower filters will help a great deal. I have an ICOM rig that needs to be centered on 1500 Hz when operating in SSB modes so I try and move them to that point if I can. Then I have DSP filters that enable me to close the "window" as tight as I need to. I also have Twin PBT which enables me to dial each side of the interference. But the actual bandpass filters are much more effective with the really strong signals.
If I could only have one additional filter than the stock SSB filter, I would go for the 500 Hz filter since it is very useful for CW use as well as narrow to medium digital modes. I have a 270 Hz crystal filter in my Kenwood TS-440SAT that I find rather narrow although some might prefer that for CW. If you go narrower than 500 Hz, you can not use a number of digital modes that are around or slightly under 500 Hz, but may not fit well into at 250 Hz bandpass. 73, Rick, KV9U Dave wrote: > Has anyone tried using either a 250 Hz or 500 Hz filter for PSK31 > reception? My Icom IC-746 (non-Pro) has no filters installed, and is > wide as a barn door on USB for PSK31. I wondered if either of these > filters would help, or would they be too narrow? > > The pass-band shift does a fair job of eliminating QRM from one side > or the other of the selected frequency, but when there are two very > strong signals within 2 Khz on each side at the same time, they just > aren't effective on both. > > Any input appreciated! > > Thanks in advance es 73 > Dave > KB3MOW > >
