The VP6DX operators mostly ran with agc OFF on all modes. There was a discussion of this subject on the Elecraft reflector in March of 2008, e.g. http://www.mail-archive.com/[email protected]/msg51762.html . This thread contains a good discussion of why agc should be OFF when running a pileup. That being said, there is a K3 firmware change now in pre-beta testing that seems to improve performance of slow agc in a pileup.
I doubt if the VP6DX folks were using the noise blanker. I think all of us have come to expect some dynamic range degradation and distortion when the nb is switched on in any rig. Dave Hachadorian, K6LL Yuma, AZ ----- Original Message ----- From: "ni0c" <[email protected]> To: <[email protected]> Sent: Friday, February 27, 2009 10:24 AM Subject: [Elecraft] K3 Cw pileup problem: effects of Noise blanker? > I've been thinking about the recently reported "cw pileup" > problem, > wondering why this apparently wasn't noticed before-- > particularly by > the VP6DX operators. > > I'm using a K3 with a single receiver, and use the three > narrowest > roofing filters, operating CW almost exclusively. In > combing through > large pileups (notably during the recent K5D operations), > I've sometimes > noticed a blurring or smearing effect caused by multiple > signals in a very > narrow bandwidth. I'm not certain of this because it is > such a dynamic > intermittent problem; however it seems to be ameliorated > when I turn off > the noise blanker. (The K3 NB is so effective, compared > to noise blankers > on other receivers I've used, that I tend to have it on > all the time). > > My guess is that the VP6DX operators probably never needed > the noise blanker in their (presumably) quiet QTH. > > It may be that the solution to this problem may be > different for those using > a single receiver K3 versus the dual receiver. It may be > that the solution could be as simple as disabling the NB > when switching from VFO A to VFO B. > > Forgive my tardy input to this conversation; however I > woke up very early this morning with these thoughts in > mind. (I wish I had some thoughts about solving the > world's economic problems.) > > 73, > Chuck Guenther NI0C > K3/100 s/n 1061 > > > ______________________________________________________________ > 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 ______________________________________________________________ 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
