In crowded band conditions, narrow filtering is often helpful. In particular, for SSB contests, a receive bandwidth of 1500-1800Hz is very effective. For me, 1500Hz (300-1800Hz) works great on the K3. There is no intelligibility above 1800Hz that is useful in a contest QSO. If you think 200-2000Hz is easier to copy (1.8kHz bandwidth), then use that. But there is no reason to use a 2.7 or 2.8kHz filter in a contest and letting in another kHz or so of QRM.
Depending on preference some people like to narrow their SSB bandwidth by using a combination of WIDTH and SHIFT. I prefer to simply reduce HI CUT because the high audio frequencies (2000-3000Hz) are the least useful in contest communication. So, it is a simple one-knob adjustment to narrow the SSB bandwidth on receive. You can select these narrow bandwidths with the K3 DSP and the stock 2.7kHz crystal filter. You don't need narrow crystal filters unless you also want protection from splatter and signal components from nearby strong signals that fall between the bandwidth of the 2.7kHz filter and whatever narrower crystal filter, e.g., 1.8kHz, you might use. 73, Ed - W0YK > During my first foray into SSB Contesting with the K3 during > WPX, I found that I need either: > > 1. Understand more about the DSP and the controls for BW, > Hcut and Lcut > > 2. Obtain a narrower roofing filter for SSB - like a 1.8 Khz filter > > 3. Or both. > > I spent some time trying to find the sweet spot in the radio > for SSB using the 2.8 Khz filter. I don't think I found it. > At least, I am not satisfied. > > I tried narrowing up the filter bandwidth to 2.4 or > 2.2....some times 1.8. > I tried shifting it up and down the bandpass. > I tried to use High Cut and Low Cut depending on where the > offending signal was coming from. > AGC was on Slow with the standard settings. > Used the RIT a lot > > It seemed I was always fighting some sort of side band > splatter or stations close in on the frequency. Maybe it was > just a crowded 20 meter band, but the same things happened on > 40 meters. > > Do I need to go to a 1.8 Khz filter to give the DSP a break? > Do I need to understand and play with the RX more to make > sure I am doing it right. _______________________________________________ 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
