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Dick PA0SE,
Fine on the test result. As you stated, the
tested T has twice the amount of top loading wire (2x 20 metres) than the L
(1x 20 metres).
It would be interesting to know if a T is
better than an L for constant length top loading i.e. what the difference is if
the upwire joins at the end or the middle of the horizontal top wire (theory
suggests the T is better as there is minimal horizontally polarised
component).
73, Bob ZL2CA
----- Original Message -----
Sent: Sunday, December 28, 2003 3:09
AM
Subject: LF: "T" versus "L"aerial
To All from PA0SE
Further to my e-mail of 26
December I measured the field strength as radiated by the aerial in
Inverted L-configuration. From this I found EMRP = 57
milliwatt.
This confirms the benificial effect of top loading.
The T-aerial radiated 140 milliwatt.
So going from
a single 20m top load wire for the "L" to 2 x 20m for the "T" resulted in an
improvement by a factor 2.46 (3.9dB) in radiated power.
The vertical
part of the "T" consisted of an open wire feedline of 11m with the two wires
connected in parallel in the attic shack. For the "L" one of the feedline
wires was removed. I assume this did not appreciably affect the
EMRP.
73, Dick, PA0SE
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