Ian White GM3SEK wrote: > > Unlike a 1.8kHz DSP filter with a 2.5kHz roofing filter, the 1.8kHz > crystal filter also avoids artefacts caused by pumping of the hardware > AGC loop by strong signals in the gaps between the wider and the > narrower passband. >
The suggestion is that a 1.8Khz roofing filter will avoid HAGC pumping if the shoulder of an s9+25dB signal is present in the 350hz gap (2500-1800/2) that would have been spanned by the 2.5Khz filter. This is true but I'd suggest that if the s9+25dB shoulder is within 350hz, there's going to be plenty of that adjacent signal spilling over into your dsp passband that's going to pump your dsp AGC. So at best you will get slight improvement with the narrower filter but I wonder if it would ever make a difference in copy ability. A narrow filter just isn't buying you that much in ssb. Barry N1EU -- View this message in context: http://elecraft.365791.n2.nabble.com/K3-Filter-question-SSB-tp6981339p6984984.html Sent from the Elecraft mailing list archive at Nabble.com. ______________________________________________________________ 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
