Hi Ivan, 250 Hz: CW and some data modes 1.8 KHz: Other data modes (MT63, WL2K) and SSB Narrow 2.8 KHz: Normal SSB 6.0 KHz: SWL (AM and DSB) and 80m AM nets 15.0 KHz: FM on 10m and 6m
The 250 Hz roofing filter works extremely well in crowded band conditions on CW. It's also just about right for low-bandwidth data modes like PSK, Thor, Olivia, etc. If you only need two, I'd go with 250 Hz and 2.8 KHz. Both are 8-pole. I say this because your main interest is in CW, and either the 2.7 or 2.8 KHz filter is needed no matter what. I've had both 5- and 8-pole filters. The skirts are somewhat steeper with the 8-pole, but both types perform quite well. Just remember that the DSP provides most of the filtering you'll hear. The roofiing filters reduce (or in many cases, eliminate) close-in blocking from adjacent interference. Very handy in crowded contest conditions. 73, matt W6NIA On Tue, 06 Aug 2013 10:37:27 +0100 (BST), you wrote: >I am about to purchase a K3 (k). My main interest is certainly CW with >occasional forays into SSB and even data, and I note the selection of roofing filters available, no doubt the 8-pole are somewhat better but what is the general feeling regarding the bandwidth(s) to be included. >Ivan G3IZD >______________________________________________________________ >Elecraft mailing list >Home: http://mailman.qth.net/mailman/listinfo/elecraft >Help: http://mailman.qth.net/mmfaq.htm >Post: mailto:[email protected] > >This list hosted by: http://www.qsl.net >Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
