I'm a bit technically challenged when it comes to filter settings in the R75, so I simply go by trial and error and what my ears tell me.
My R75 is in mint condition; I have neither modified it (except for installing the DSP module), nor have I installed any optional filters since I bought it new in 2000.
Here are the filter settings I prefer for USB/LSB modes:
455K: 6
9M: 2.4
The audio in USB mode sounds fine with both twin pass-band tuning knobs centred (i.e. the normal setting), so why is there a lot less treble in LSB mode, so that I have to adjust the PBT to correct it?
If I use narrower or wider filters for SSB I notice the discrepancy there, too, but not as much.
By the way, I rarely use the narrowest filters for sideband, since I haven't encountered much QRM from adjacent stations lately, but 2.4 and 2.4 does occasionally help eliminate some background noise. Actually, the twin PBT feature is often much more helpful than the filters, anyway.
My R75 is in mint condition; I have neither modified it (except for installing the DSP module), nor have I installed any optional filters since I bought it new in 2000.
Here are the filter settings I prefer for USB/LSB modes:
455K: 6
9M: 2.4
The audio in USB mode sounds fine with both twin pass-band tuning knobs centred (i.e. the normal setting), so why is there a lot less treble in LSB mode, so that I have to adjust the PBT to correct it?
If I use narrower or wider filters for SSB I notice the discrepancy there, too, but not as much.
By the way, I rarely use the narrowest filters for sideband, since I haven't encountered much QRM from adjacent stations lately, but 2.4 and 2.4 does occasionally help eliminate some background noise. Actually, the twin PBT feature is often much more helpful than the filters, anyway.