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Re: Topband: Bury beverage wire?

To: topband@contesting.com
Subject: Re: Topband: Bury beverage wire?
From: Martin <dm4im@t-online.de>
Date: Wed, 17 Jan 2018 17:10:04 +0100
List-post: <mailto:topband@contesting.com>
Thanks to all.
I had a few direct responses to my inquiry.
I should haver better described the situation by expressing that it is not a driveway, but rather an opening in a fence separating 2 lawns. I just had no words for it in english.

One guy came up with the idea to thread the wire through tennisballs and bury it in a conduit, so no portion of the wire would touch ground or the conduit.

This seems like a good idea, but isn't just burying coaxcable , leaving the shield open and only use the center conductor about the same, without a bunch of unknown parameters?

Another suggestion was to bury coax and start the antenna after the opening. Excellent, but last resort, because this would only allow a 180m long antenna. Still better than no antenna and better than most hams can do.

W3LPL came up with what i think is the best idea:
Bury coax with high VF and put transformers on both ends.
This leads to another question:
What ratio do i wind the transformers? 1:9 at the feedpiont, 9:1 at the beginning of the coax, 1:9 at it's end where the wire continues? Or do i measure the impedances to calculate a ratio? Do i put in a ground rod at each end of the coax to connect the transformers?
Do i connect both sides of the transformers to ground?

If i get this to work, i have a 230m-235m long antenna with 5m of it under ground.

Any input?



--

Ohne CW ist es nur CB..

73, Martin DM4iM
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