FYI, I don't want to open up a 'can of worms', and Rob Sherwood could better speak to this, but this is an observation I made using a P-3.
Not long ago, there was quite a string of threads about the 5 pole 2.7 Khz roofing filter versus the 8 pole 2.8 Khz filter. Before I ordered my K-3, I had studied the filter skirts of each. I don't remember how I found the plot for the 5 pole filter, but I remember that the span of each was different. At the same span width, the 2.8 Khz filter skirts seemed to me to be considerably straighter when compared to the 2.7 Khz filter, so I ordered the 2.8 filter. The other day, I was on a qso with a group and while watching the SSB signal on the P-3, I noticed a carrier much taller appear right on the edge of the filter bandwidth as shown by the brackets at the bottom of the P-3. The carrier was on the far end of the filter, or 2.8 Khz away from the center frequency. I could not hear it, but expected to, so I tuned over slightly to get it within the filter bandwidth and heard it strongly. I seem to recall that a filter's width is rated at something like 6 dB down, so I thought I would have heard it within the skirts at their wider limits. I still wonder about that, but I'm very pleased. (Just a comment; I'd hate to do without the P-3) Richard Fjeld, n0ce rpfj...@embarqmail.com I'd rather be learning. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
