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Old May 22nd 08, 06:56 PM posted to rec.radio.amateur.antenna
Michael Coslo Michael Coslo is offline
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First recorded activity by RadioBanter: Jun 2006
Posts: 828
Default antenna construction

W3CQH wrote:
"W3CQH" wrote in message
. ..
Sorry for the repost - I was trying to get the visual dimensions correct!

The following represents my roof and the tree in my backyard.

The length of the roof is 90ft,
it is 15ft from the center line to
each edge, (roughly 30ft),
height of roof is approx 22ft at the
peak and 10ft at the gutter edge..

The tree is approximately 35ft high.

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

x
O x
x
x
x -------------------------------------------x
x
x
xxxxx x O x
x O x xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
xxxxx
TREE

My question is: do you think it would be better to run a configuration as
say a Windom from the tree to the points on the roof (the points can be
moved) or just a simple inverted "V" and the angle of the "V" in any case
is
going to be very narrow. I would be feeding either one via some Rg8x
approximately 65ft.

I would like to be able to use the ant from 160m - 6m if possible, I will
be
feeding it via a tuner, and the wire is going to be #26 enameled as it
can't
be seen.

Comments please.


Guess I'll reply to this one! ;^)

How much total length will you have? A Windom for 160 needs 260 feet.
I used a windom for a while because it was convenient, the short leg
dropped the coax directly down to my shack window. The antenna performed
okay. Depending on your lot size, you might not be able to run a full
160 meter version. would 80 meters be an okay bottom limit? Even if you
had to let the ends drop a bit, though tuning (short vs long leg) will
be a little different.

Inverted v might also be a little difficult. You might want to go for a
plain dipole.

I'm pretty dense today - getting over a nasty head cold, so I'm going to
ask a few questions.

You just have the one tree?

If so, where are you planning to hang the other end of the dipole.
Certainly an inverted V is going to need something in the middle.

With the tree at 35 feet, what is the maximum height you can hang a wire at?

It doesn't sound like a real optimum site, but don't worry, we can get
you something that will work okay.

- 73 de Mike N3LI -