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Old March 23rd 08, 08:18 PM 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 80m inductor kit or a pair of 80m traps?

"Barrett" wrote in
k:

I have up a half size G5RV and want to add 80 metres it. I don't have
the space for a full size.

What is best to go for a 80m inductor kit or a pair of 80m traps?

Thanks



Reading through the responses, it seems that your requirement is actually
for a shortened wire antenna for 80 and 40.

The starting materials are a half sized G5RV (which is not a G5RV, but
one of the many variants).

You could salvage materials from the G5RV to make a trapped 80/40 dipole.

(The traps do not simply work as an on/off switch to disconnect the end
sections as implied by some. They might be seen to work that way if they
were resonant at the operating frequency, but they need not be, and there
is good reason for them to not be resonant at any operating frequency.)

Google around for designs for an 80/40 trapped dipole, there are plenty.
Decent articles will include details of the physical construction of the
traps.

There is a design on my web site, but it is probably too long for you (we
don't know your length requirements other than less than a G5RV, you
chose to not share that). Nevertheless, it might be an interesting read,
see http://www.vk1od.net/coaxtrap/8040.htm .

These type of antennas are affected by their environment, so you should
expect to need to fine tune the configuration. Be wary of varying
specific trap designs, you might dig a hole for yourself.

Owen