At 07:05 PM 9/29/98 -0600, you wrote:
>Gentelmen, I just bought a used Telrex 3 element 20 meter monoband beam,
> The hardware is the heaviest duty I have ever seen. The 4 picture pages
>insrtuction I got with it are somewhat sketchy as far as instructions go,
>but I can figure almost everything out. I just have 1 question.
> The manual shows a coaxial balun. the picture shows it, but
> there is no
>mention of how long the coax is supposed to be. The drawing has an inset
>that says 1/2 wavelength. I cant imagine this balun is supposed to be 32
>feet long. The previous owner showed me the balun he had on it. Its 24 feet
>long, but he cant remember why. Anybody have information about how long this
>balun is supposed to be? The manual is very vague.
> Thanks for any help,
> Dave McPhie K7SX
Dave, it is a 1/2 wave 4:1 coaxial balun as covered in the various
antenna handbooks and ARRL Handbooks. The coax length
is 1/2 wavelength long TIMES the velocity factor of the cable used.
This works out to be about 22.95 ft long for 14.150 MHz and a VF or
0.66 for RG-213.
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