It seems that soundcard based "AFCW" has become popular with some contesters, for reasons which elude me. There is great opportunity to transmit wide, distorted cw signals if things are poorly adjusted.
Bob W2WG -----Original Message----- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Gregory Fischer Sent: Sunday, February 22, 2009 7:59 PM To: K2MK Cc: Elecraft Reflector Subject: Re: [Elecraft] K3 receiver desensing on CW during contest This is more than likely due to dirty signals on the TX end. I was using a QS1R connected to the K3 IF and measured the width of some of the strong signals. Some were as wide as 2.6 kHz!!!! Not very good for a CW signal. In this case there is just not much you can do. 73 Greg AB7R On Feb 22, 2009, at 4:45 PM, K2MK wrote: > I had a great time with my K3 during the ARRL DX contest. I do S&P > and I was > trolling around with my filter width at 50Hz. Absolutely > outstanding. The > auto spot is equally outstanding. > > At 50Hz width it was quite clear that many stations call off > frequency. > Using RIT, I could see that it was typical for them to be 70Hz or > more away > from the DX station but I could not hear them in my 50Hz passband. > The real > problem was when one of them was S9 or greater. They completely > swamped > weaker DX stations. Sound within the passband just blanked out. No > band > noise and no DX station. And there was no recovery between dits and > dahs. It > was actually easier to copy the DX station when people were calling > directly > on top of him. You could at least hear him between the dits. > > (Obviously if I was calling CQ instead of S&P I would have a wider > passband > and I would have just worked the stronger off frequency station). > > For my style of operating this was a disappointment. I tried AGC-F > and AGC-S > but I forgot to try AGC off. I also varied the AGC THR and AGC SLP. > I tried > NR off and on. (I was not using NB). I tried PRE and ATT off and on. > I tried > riding the RF gain. I tried shifting the passband but shift doesn't > work > well when the width is only 50Hz. Nothing helped. I also tried > opening up > the passband. That didn't help either but I don't remember the > results. > > This was not a one time thing. It happened at least 20 different > times on > different bands. I guess this is perfectly normal. I was just > wondering what > operational trick is available to compensate. > > 73, > Mike K2MK > > ______________________________________________________________ > 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 ______________________________________________________________ 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 ______________________________________________________________ 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
