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Old October 18th 05, 08:25 PM
Amos Keag
 
Posts: n/a
Default Doublet Antenna question

600 ohm open wire line is available from W7FG [800-807-6146].

50 feet $23
100 feet $40.

I've used it for years at the KW level. No problems.

I'm just a satisfied customer and have no financial interest in their
business.



Ed wrote:

That's the antenna I was offering to model for you. You will,
no doubt, run into some pitfalls, for instance an impedance
of 8 ohms or 4000 ohms that your tuner may not be able to handle.
EZNEC can predict such problems before they bite you.



OK. I'll take you up on the offer, afterall. Figure 100' of #14
copperweld, centerfed with 450ohm ladderline or with 600 ohm open wire
line (2"). Height should be about 45' at ends and 35 feet center.
Length of feedline is projected at about 45 feet.

I'll go with the 600 ohm wireline feed if I can find it, otherwise,
the cheap 450 ohm plastic stuff for now and build wireline next summer.



EZNEC can also predict your radiation patterns which are important
on the high bands if you want to hit certain areas of the world.
Rotating my dipole in AZ by 15 degrees made a lot of difference.



Not real concerned with the patterns of anything above 40M. I'm
mainly interested in 80/75/60/40M use. I'll take what I get and see
how it goes..... might be nice to see 20M and 10M patterns, though.
Thanks.


Ed