Can't speak for Bill, but for myself, all night long on 75 and 40 meters. There are people that show up with amps and antennas that you almost never hear outside of a contest. NQ4I near Atlanta has a 12 element LPDA for 80/75 meters fixed northeast. 4 or 5 elements active on any given frequency. What do you suppose that's like downwind?
73, Guy. On Sat, Jan 14, 2012 at 9:06 PM, DOUGLAS ZWIEBEL <doug...@gmail.com> wrote: > IMHO, there are few folks in the contest world that are better > technically than Bill (W4ZV), so I would suggest that everyone take > his comments very seriously. > > Bill...I do have a question or two, with respect to your statement below. > > 1. Just how often do you find that you run into a situation such as > you describe below? I don't mean simply, "during every a contest," I > mean more like how often during a contest? For how many Q's? > > 2. If the really close and really strong signal is pumping your AGC, > why not just turn off the AGC and ride the RF? This is not a > rhetorical question, because I know you do this. So I'd like to learn > why you would, in some situations, prefer to not do that. I would > love to learn a new trick! > > 3. And just out of curiosity (on SSB), how long would you tolerate > being so close to someone who would pump your AGC? Of course, for me > (QRP), the answer is zero seconds. :-) > > W4ZV said: > I agree IMD reduction is not a big issue on SSB but blocking dynamic > range (BDR) is the primary reason I sometimes need a narrower filter. > If you have an S9+25 SSB signal CQing next to you (sometimes the case > in crowded contests), a narrower filter will prevent it from > de-sensing your receiver. If part of the interfering signal falls > inside your 2.7k filter, signals on your frequency will be gain > modulated by his signal (commonly called AGC pumping). In this case > a narrower filter will prevent the problem. Of course when this > happens, we still have to contend with his transmitted "splatter" > (typical SSB TXs run -35 dB IMD which would result in ~S7 splatter > from an S9+25 signal), but at least you can still copy signals at S7 > or above (and lower when he's not transmitting). > > 73, Bill > ______________________________________________________________ > 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
