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Re: [TenTec] was OT: Indoor Antenna: re B&W type terminated dipoles

 To: Discussion of Ten-Tec Equipment Re: [TenTec] was OT: Indoor Antenna: re B&W type terminated dipoles Steve Hunt Discussion of Ten-Tec Equipment Tue, 07 Dec 2010 18:02:09 +0000 mailto:tentec@contesting.com>
 ```I'm puzzled by most of what Jim wrote. "Efficiency" is a term well understood by most professional engineers as: Efficiency = Pout/Pin If we are talking specifically about an antenna's efficiency - not an antenna *system* - the expression becomes: Efficiency = (Radiated Power)/(Power input) = (Power input - Losses)/(Power input) The only losses in a simple antenna are I^2*R losses in the element(s). If we take a resonant 20m half-wave dipole constructed from #14 wire, its efficiency is about 98.5% (-0.06dB); if we operate the same antenna on a different band - say 17m - the efficiency improves to 98.9% (-0.05dB). The efficiency of a Double Bazooka will be lower than that of a half-wave dipole because of extra losses in its coax stubs. 73, Steve G3TXQ On 07/12/2010 11:58, Jim WA9YSD wrote: > Any antenna for that matter looses 1/2 their power or more when operated on a > band that it is not designed for. > > Efficiency for a folded dipole has a factor of around 0.98 > Efficiency for the common dipole is about 0.1 > Efficiency for the Double bazooka is about 0.89 > > Efficiency for the above cases is its ability to couple. So your use of the > word efficiency must be defined better so it is not so confusing as to what > exactly your talking about. > > > Stay on course, fight a good fight, and keep the faith. Jim K9TF/WA9YS _______________________________________________ TenTec mailing list TenTec@contesting.com http://lists.contesting.com/mailman/listinfo/tentec ```
 Current Thread Re: [TenTec] was OT: Indoor Antenna: re B&W type terminated dipoles, Jim WA9YSD Re: [TenTec] was OT: Indoor Antenna: re B&W type terminated dipoles, Hank Garretson Re: [TenTec] was OT: Indoor Antenna: re B&W type terminated dipoles, Dr. Gerald N. Johnson Re: [TenTec] was OT: Indoor Antenna: re B&W type terminated dipoles, Steve Hunt <=