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Re: [TenTec] Transmission Line Loss due to SWR

To: Discussion of Ten-Tec Equipment <tentec@contesting.com>
Subject: Re: [TenTec] Transmission Line Loss due to SWR
From: "Martin, AA6E" <martin.ewing@gmail.com>
Reply-to: "Martin, AA6E" <martin.ewing@gmail.com>,Discussion of Ten-Tec Equipment <tentec@contesting.com>
Date: Wed, 5 Oct 2005 00:33:45 -0400
List-post: <mailto:tentec@contesting.com>
Don't these numbers apply to "long" lines (many wavelengths and/or an exact
multiple of a quarter wavelength)?

I have been wondering about the following: If you have a short line, the
loss should be different. That's because the loss is normally due to I^2R --
it mostly arises where the current is maximum. If you have, say, a line less
than 1/8 wavelength long feeding a high Z load, the loss should be rather
small, because the entire line is high voltage / low current.

This is probably not important for most antenna applications.

73 Martin AA6E

On 10/4/05, Sinisa Hristov <shristov@ptt.yu> wrote:
>
> Following the recent discussion of open wire feedlines,
> I've compiled a 3-page PDF with some useful details.
>
> The 70 KB file can be downloaded from:
> http://www.geocities.com/va3ttn
>
> Basic definitions and explanations are given,
> along with two tables giving total loss and additional loss
> in the presence of mismatch.
>
> Open wire lines can achieve "low loss in presence of high SWR"
> only to a limited extent, just like other lines.
> The tables given should assist in making right decisions.
>
>
> 73,
>
> Sinisa YT1NT, VE3EA
>
> _______________________________________________
> TenTec mailing list
> TenTec@contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec
>



--
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http://blog.aa6e.net
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