NVIS information is almost always anecdotal and a myth, more than science! As I have told many participants in many presentations, "If you think lowering your antenna will make your signal stronger, expect your QSL cards to arrive on a unicorn." How many of you looked at Jim's, K9YC, explanation? Probably too few.
40m is near the upper limit of NVIS and currently, it is often below the NVIS frequency. At this point in Cycle 25, I frequently can't copy stations within 150-250 miles away on 40m here in NM. The ones I copy best have the highest, NOT lowest, antennas. Note, as shown in Jim's paper, an 80m dipole at 60 ft. provides the maximum NVIS signal while at one at 90 ft. is just 1 dB down. Having operated with an 80m dipole at 75 ft. on an Air Force RADAR site, my 100 Watt signal was almost always stronger than those with lower antennas around MI. Yes, that is anecdotal, but it agrees with the science as modeled in Jim's paper. I have yet to read of anyone's scientific data showing their 10 ft. high dipole worked better than their 30 ft. high dipole on 40m, to say nothing of similar 80m dipoles. If you have two WSPR transmitters and have antennas at these heights, gather some data. Both transmitters must transmit the same level signals at the same time over time to collect meaningful data, assuming everything is equal. I once worked a station in Italy on 20m SSB with my KX3 using my mobile antenna. I did not replace much better antennas at home based on that anecdote. Neither have I received any QSL cards on unicorns although I do have a unicorn graphic in some of my antenna presentations. 73, Bill Mader, K8TE New Mexico QSO Party 9 Apr 2022 Secretary/Treasurer and Past President, Albuquerque DX Association W6H NM Coordinator, Route 66 On-the-Air 10-18 Sep 2022 ______________________________________________________________ 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 Message delivered to [email protected]
