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Please disregard the posting below as I misunderstood Roy's posting was in
reference to a different thread. Sorry about that Art " wrote in message news:unWae.17625$NU4.2343@attbi_s22... Interesting comments Roy But it does utelize the use of dipoles that are not straight but angled. It is well known that pointed /angled dipoles does have advantages such as reducing rotational area, reduction of reactances that can lead to as much extra gain as 1 Db together with a broader banded antenna. In this particular case he has achieved an extra 3 db by stacking. Your point regarding direction of main lobs is quite important but lessens in importance if the antenna is rotatable. Unfortunately I searched the web page of this new antenna but was unable to find any antenna patterns, which puts one in a "believe it or not" situation regarding its capability versus claims. Art "Roy Lewallen" wrote in message ... I presume you realize that a 3/2 wave dipole has multiple lobes, with nulls between. At many or most angles, a half wavelength dipole has greater gain. You can get just two narrow lobes from a 3/2 wave dipole by rotating the wires 30 degrees to form a horizontal "V" having a 120 degree included angle. I've used this trick with a 40 meter dipole being used on 15 meters -- it doesn't have much effect on the 40 meter pattern. (You'll see some TV antennas made this way for the same reason -- the high TV channels are about 3 times the frequency of the low channels.) But again, if a station isn't in the right direction, you'll do better with a half wave dipole than a 3/2 wave one. A "gain" antenna isn't of much use if the gain is in the wrong directions. In fact, it's worse than a lower gain one, since the higher gain it gets in a few directions comes at the expense of lower gain in the remainder. Roy Lewallen, W7EL Buck wrote: When trimmed to SWR, I get less than 1.5:1 on fifteen meters. My plans are to build a multiband antenna, parallel elements, where each band is 3/2 wave dipoles and fed with 50 or 75 ohm coax. I haven't tried this yet, but I would hope I can have a few gain dipole antennas in a multi-band format. |
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