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On Tue, 24 Aug 2004 00:54:10 GMT, Richard Clark
wrote: Now, I know that such antennas are not designed to be transmit antennas (and again, perhaps too short to boot); so I will leave that to others to engage as a receive antenna if they doubt reciprocity (or I will do that later this eve for them as I often have to). Hi All, I've repeated the models with longer runs: 1000 meters length @ 80M. For transmits, the single wire over ground shows a gain of 0.42dBi at 10° but with a F/B of 16.4dB. EZNEC proclaims the model exhibits 17dB loss. For transmits, the double wire over ground shows a gain of 1.2dBi at 10° but with a F/B of 11.7dB. EZNEC proclaims the model exhibits 17dB loss. However, Beverages are not typically the first choice for transmission, but rather reception. Does reciprocity hold? As no one has offered to help the Little Red Hen, would they care to share in the cake? For the receive single wire Beverage @ 10° w/600 Ohm load Total load power = 5.543E-07 watts For the receive double wire Beverage @ 10° w/600 Ohm load Total load power = 6.623E-07 watts Now, if we compare the two receive loads we find they differ by .77dB which is the same difference for the transmission models. By most accounts, that means reciprocity prevails. By further accounts, that means the double wire system is superior - if you want to lay out 1000 meters of wire for less than one dB (that pesky one dB value judgment again). By this point, what with all the trolling going on and so little actual technical content, What was this all about? 73's Richard Clark, KB7QHC |
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