Some of us deliberately operate with the roofing and DSP at the same bandwidth, and with some care to get the skirts coincide. This provides the maximum possible drop at the edges, quite useful in a crowded contest. I want to hear equally well in a specific bandwidth, and then I want the selectivity skirts to drop as close to straight down as possible.
Generally not needed for casual operation, and I will operate the casual QSO's sometimes with the DSP bandwidth at 700 or 800 Hz just because it "sounds better". and 1.8 kHz (the contesting SSB width) roofer behind it. Get people too close and I just tighten the width back up until I don't hear them any more. Generally people seem to give you 1 kHz spacing for casual. 73, Guy K2AV On Tue, Jan 31, 2017 at 9:26 PM, Don Wilhelm <donw...@embarqmail.com> wrote: > Andy, > > For normal operating, you will not find the 1kHz filter any more > beneficial than using the 2.7 (or 2.8) roofing filter. > The ultimate selectivity is provided by the DSP bandwidth, and not the > roofing filter. > > The reason for the more narrow roofing filter is to provide isolation from > nearby strong signals that are within the roofing filter passband, but > outside the DSP bandwidth. If strong signals come into the K3 outside > theDSP bandwidth, but inside the roofing filter bandwidth, they can cause > AGC "pumping" and reduce the overall sensitivity of the K3 receiver as a > result. > > If you are operating in contest situations, or trying to respond to DX > stations who are 'working a pileup', that extra bit of roofing filter may > be needed, but for more casual operation, save your money. > > 73, > Don W3FPR > > On 1/31/2017 9:07 PM, abulling...@comcast.net wrote: > >> I just got my new (used) K3/10 in the mail yesterday and have been having >> a blast with it. It came with the 2.8 SSB filter and the 400 hz CW filter >> and I have been told by a couple friends on the air who also have K3s that >> that’s all I need. >> >> But...nature abhors a vacuum. On my filter board. I was thinking >> seriously of the 1 khz CW filter because I do a lot of rag chewing on 80 >> meter CW and I would think that filter would cut down the noise a bit and >> the 500 hz 5 pole filter with the gentler sloping skirts and either the 200 >> or 250 for when things get really hairy. But maybe I’m off base here >> because I see very little talk of the 1 khz filter. I would love to hear >> thoughts on this. >> >> The guys are telling me forget all that and just get the KPA3A so they >> can hear me better. Which I will do just to quell the griping but I notice >> they are copying everything I send at 10 watts. >> >> I am looking at all the ideas you guys gave me a few days ago as well and >> thanks a lot for the suggestions. I think this may be the most fun I’ve >> ever had with a new rig. It’s just an amazing radio. >> >> ______________________________________________________________ > 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 > Message delivered to k2av....@gmail.com > ______________________________________________________________ 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 Message delivered to arch...@mail-archive.com
