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Old July 25th 07, 05:29 PM posted to rec.radio.amateur.antenna
DeanO DeanO is offline
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First recorded activity by RadioBanter: Jul 2007
Posts: 5
Default Question 1/4 Wave Ground Plane Measurements

On Jul 25, 11:47 am, Bam Bam wrote:
I am making a simple 1/4 wave ground plane antenna and have two rather
silly question regarding its measurements.

1. I've attached an SO-239 connecter to a 5x5 inch aluminum plate.
When measuring the length of the radials, I measure from the center
conductor of the SO-239 to the end of the radial taking into account
the plate, correct?

2. If I make a loop in the vertical radiating element so that I may
hang the antenna, does the circumference of the loop count in the
measurement of the element or the diameter? (e.g., if I need 20 inches
for the element, do I measure from the bottom of the SO-239 to the top
of the loop or do I take a 20 inch wire and make a loop not caring
that it has shortened the element slightly?)

Thanks

Bam Bam

PS I would only measure to the top of the loop... not counting the
'fold over' that makes up the loop. The wire actually folds back down
the main radiator and thus cancels its lenghting effect (except for
the small capacitance I talked about).