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Old April 6th 07, 02:32 AM posted to rec.radio.amateur.antenna
Owen Duffy Owen Duffy is offline
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First recorded activity by RadioBanter: Dec 2006
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Default Calculating trap capacitor voltage rating

Rick wrote in newsan.2007.04.05.23.29.53.793507
@reply.in.gp:


How do I calculate the voltage rating I'll need for capacitors used to
make traps?

I am making a portable field antenna for 160 through 40 meters, for use
with 100 watts absolute maximum (normal use will be from 5 to 50

watts).


The antenna can be designed so that traps are not resonant at the
operating frequency, and that tends to reduce the voltage impressed
across the traps.

Modelling might give you the best indication of the operating voltage on
the traps. Don't forget to allow for peak and a safety margin.

Another approach is the so called coax trap. I have seen many
descriptions of these things, and they are all different, so I thought I
would write my own which, in keeping with the others, is also different.
My approach was to describe them using a transmission line explanation.
Such an explanation suggests they are a lot better than at first might
meet the eye. My notes are at http://www.vk1od.net/coaxtrap/index.htm .

Owen