Bill W4ZV wrote: > > >Gary Hvizdak wrote: >> >> If instead you think that there might be a greater demand for some other >> bandwidth 8-pole INRAD roofing filter, please email me (off-Reflector) to >> let me know that width and include your reasoning for desiring that other >> width. >> > >I'd be interested in a **true** 6 dB BW 8-pole for 200-250 Hz (Inrad's "250" >is actually 370 Hz BW and I don't want that).
Yes, the real gap in the available range of roofing filters is an 8-pole with a *true* 6dB BW of 250Hz. As for the choice between 250Hz and 200Hz, I have tried both bandwidths by modifying a stock 200Hz 5-pole filter (with design help from Wayne). In real-life contest QRM there is no noticeable difference between the two bandwidths on CW, but there is a huge difference for RTTY. With 170Hz shift, a 250Hz filter is very close to the lower limit of usable bandwidth, but definitely on the right side of the line - in heavy RTTY QRM, a 250Hz filter can be a game changer. But 200Hz is below that limit, not usable at all. For those reasons I would support 250Hz because it would meet the needs of more users, but would vote against 200Hz (and in this, I do literally mean "vote with my pocketbook"). -- 73 from Ian GM3SEK http://www.ifwtech.co.uk/g3sek ______________________________________________________________ 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
