True rhombics are hard to rotate. Even harder is finding the space to put one up in the first place. See what your HOA has to say about it. 73 Fred, AE6QL
-----Original Message----- From: Elecraft [mailto:[email protected]] On Behalf Of Ron D'Eau Claire Sent: Thursday, December 10, 2015 8:43 PM To: [email protected] Subject: Re: [Elecraft] Antennas with resistor and OCFD. Fred, K6DGW wrote: Ummm ... rhombics *always* work well for their intended use. Unterminated, they are bi-directional. With the terminating resistor, they are unidirectional in the direction from the feedline to the terminator. Since terminated rhombics are usually 2 or more wavelengths on a side, they have very narrow beamwidths with a big F/B ratio, low radiation angle, and high gain. ------------------------ Quite so but it's worth noting that the unidirectional characteristics obtained with a terminating resistor did not result in any additional gain. Instead, the resistor absorbed the RF that would have been radiated on (or received from) the reciprocal heading, giving the array its unidirectional characteristic. Yagi's, quads and similar arrays gain a stronger main lobe by suppressing radiation in other directions. A rhombic is a classic example of how the best design is not always the design that radiates the most RF. The problem with a rhombic for Ham use on the HF bands is that they tend to be an absolute beast to try to rotate. 73, Ron AC7AC ______________________________________________________________ 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] ______________________________________________________________ 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]
