[amsat-bb] Re: Antenna element and Boom material
ko6th.greg at gmail.com
Mon Aug 12 19:48:07 PDT 2013
Yes, the length of the elements will be affected. Fatter elements look
electrically longer, I think, so they may need to be shortened a bit to
compensate for a shift in frequency. Impedance may be affected as well.
You will also need to keep the same mounting scheme, as to whether the
elements are insulated from the main boom or not.
But, experimenting is what it's all about. Build it and see how it
performs. Adjust. Do it again. You will end up with a good antenna,
and a practical knowledge of how to build it, when you're done. Then
let us know how you did it.
Mike Hoblinski wrote:
> I was looking at constructing a Log Periodic antenna and was wondering
> about useing square material instead of round elements. The plans call out
> 1/4 round hollow tube for the elements. I ran across some aluminum extrusion
> material from a company called Microrax http://www.microrax.com/ that sells
> small aluminum extrusion and brackets plus hardware.
> Their extrusions are 10mm square and come in legnths up to 35 inches. I was
> looking at going with some larger extrusion material for the boom. All of the
> extrusion material has nice channels cut into it that could be used for element
> spacing adjustment and easy mounting. My other thought was to tap the ends of
> the elements and add stainless steel screws to adjust the legnths.
> I am wondering about going from 1/4 inch tound elements to about 3/8 inch square
> would effect the performance of this antenna.
> Mike Hoblinski
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