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Old January 9th 09, 02:24 PM posted to rec.radio.amateur.antenna
Cecil Moore[_2_] Cecil Moore[_2_] is offline
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First recorded activity by RadioBanter: Mar 2007
Posts: 3,521
Default Installing a Ladder Line to the house

Dave wrote:
A transmatch between the radio and the transmission
line does little to make the antenna work better.


That statement is true for a very lossy system but
not necessarily true for low-loss real-world systems.

Establishing a conjugate match at the antenna feedpoint
makes the antenna work better by allowing maximum
available power transfer to the antenna. A remote
autotuner at the base of the antenna can accomplish
that feat.

There seems to be developing the myth that a tuner
at the shack cannot accomplish that feat. Although
strictly technically true, a low-loss tuner and low-loss
transmission line can come close enough to achieving a
conjugate match at the antenna that almost all of the
available power is transferred to the antenna (if losses
are made negligible by good engineering practice).

It can be proved mathematically that in a lossless
system, a conjugate match is established at the
antenna feedpoint by the tuner located back in the
shack. A near-conjugate match is established in the
case of a low-loss system resulting in near-maximum
available power transfer to the antenna.
--
73, Cecil http://www.w5dxp.com