For narrow receive SSB filtering (crystal and DSP) for contesting and other crowded band conditions, use the HIGH CUT control rather than WIDTH and SHIFT.
In an earlier post, I reported that the K3 1.8kHz crystal filter is excellent for SSB contesting and had no degradation of audio quality over the 2.1kHz filter, at least to my ears. I noted that the IF needed to be SHIFTed lower by 500Hz with the 1.8kHz crystal filter for best sounding audio. Wayne just pointed out to me that rather than having to adjust two controls (WIDTH and SHIFT) to go from 2.8 to 1.8kHz in SSB, that the HIGH CUT control could be used instead to move from 3.0kHz to 2.1kHz, at which time the 1.8kHz crystal filter automatically kicks in. Carrying this one step further, I reduced HIGH CUT to 1.2kHz, yielding an overall 1.0kHz bandwidth and causing my 1kHz crystal filter to kick in for IMD protection of the DSP IF. (NOTE: I had to enable FL3 = YES for SSB so the 1kHz crystal filter was available.) The audio was still quite intelligible, entirely adequate for contesting, but was a little low for my taste. I found that at a 1kHz SSB bandwidth I prefer to stop HIGH CUT at 1.3kHz and move LOW CUT up from 200 to 300Hz. Individual preferences may cause different operators to prefer slightly different combinations of LOW and HIGH CUT settings to achieve the desired bandwidth, especially at the narrowest bandwidths. But, for me it is simple by adjusting HIGH CUT downward until the bandwidth is about 1.3kHz or so, then I like to narrow it further by raising LOW CUT. YMMV, as its said. If you are on the fence about what narrow crystal filter(s) to install for SSB, spend some time listening around the bands by setting your HIGH CUT to 2.3kHz (2.1kHz bandwidth) or 2.1kHz (1.8kHz bandwidth) or even 1.2kHz (1kHz bandwidth). This will show you exactly what the K3 sounds like if want to use a narrower crystal filter. You'll be surprised at how narrow you can go and still have excellent readability. 73, Ed - W0YK _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
