Quote:
Originally Posted by Tower Guy
WNYT-18 is at 183 degrees true, WMFP is at 121. The difference is 62 degrees.
A half wavelength on channel 18 is 11.88 inches.
If you build two right angle extensions and position the top antenna more toward WMFP and the bottom antenna further from WMFP, there is a magic distance when WNYT will be in phase while WMFP is out of phase. That distance is 1/sine62 * 11.88 inches = 13.45 inches. Therefore boom two offsets of 6.7 inches, one left and one right of the mast, and you'd drop the signal strength of WMFP by 15-20 db while not changing the signal strength of the main beam on any frequency.
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OK, I think I'm reading that the 2 log periodic antennas would be in a
V shape from the mast, with the outer booms tips separated at 13.45 inches? The right angle extentions comment does confuse me.
I will try that, but I've also noticed that the full wavelength of RF 18 (497 mhz) is 34 5/8 inches, the log periodic's boom length is 35 inches, when the beams are pointed at Bald Mountain, the booms would point towards Boston from the side and are almost a full wave resonent length, maybe acting as a pair of phased, sudo-dipoles? As said, I can't lock WMFP, but the TV knows it's seeing some kind of strong RF.
I also have another UHF loop antenna and the original WRGB home brew dipole antenna I will set at 497 mhz length that I plan to test with, just to prove or disprove the sudo-dipole thing and also trying reception from Bald Mt. at a lower height here then the main array is...the loop is portable on a mast and I will move it around the property, sniffing for WNYT 18. I haven't done any field testing in a very long time, this may prove to be fun.
EDIT:
My reference above to 34 5/8" is incorrect....24 5/8" correct, apparently, I can't add correctly, so that theory is out....I continue the hunt.