VE3KI wrote: > As someone who mainly operates during CW and RTTY contests, I > draw a slightly different conclusion from Craig's and Jim's. > In the absence of a true 270 Hz roofing filter, the existing > "250 Hz" filter appears to be the best roofing filter option > on offer for RTTY contest use. Therefore, while I agree with > Ed's conclusion about these two filters, of the two the one > that is unnecessary for me is the 400 Hz filter.
Same here. For the record, I use 8-pole 500 Hz INRADs for CW. I use the 8-pole 370 Hz (labeled 250 Hz) for RTTY with the DSP Dual-Tone Filter. The 5-pole 200 Hz works for RTTY, but rolls off the outer edges of the tones (especially in conjunction with the Dual-Tone Filter) and I prefer the steeper skirts on the 8-pole 370 Hz filter. It is enough wider than the DSP filtering such that little cascade roll-off occurs. > From amongst the existing choices, a 500/250 combination > seems most effective for my situation. If I were more heavily > into 160 CW as compared with RTTY, I might opt for a 400/200 > combination instead. For a single roofing filter for CW/RTTY > use, you might find a 400 to be the best single-filter > compromise. Different solutions for different situations. Exactly. There isn't a single solution for all scenarios. That's why there are filter sockets and a range of alternative filters. The key is to understand how the K3 filters work (both DSP and crystal) so that thoughtful choices can be made by each individual. 73, Ed -------------- Ed Muns - W0YK www.w0yk.com > Craig AC0DS wrote: > > > I agree with you that there is no need for the 250 Hz 8 pole > > option. > > Jim Brown K9YC wrote: > > > Indeed, there is no good > > reason for the EXISTENCE of this particular 250 Hz filter, > > primarily because it is NOT a 250Hz filter by any reasonable > > measure. > > and Ed Muns W0YK wrote: > > > Accordingly, in their application as > > roofing filters for the K3, I see no reason to have both > the "250" and the > > "400" in the same receiver. ______________________________________________________________ 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
