RFW,

What would be your evaluation of these three
SWL (Receive Only) Inverted "L" Antennas:

* 49M Band Half Wavelength Inverted "L" Antenna
Vertical 27.6 Feet and Horizontal 55.1 Feet with a Total of 82.7 Feet
- - - V = 1/6WL & H = 1/3WL

* 49M Band Three Quarter (3/4) Wavelength Inverted "L" Antenna
Vertical 41.4 Feet and Horizontal 82.7 Feet with a Total of 124.1 Feet
- - - V = 1/4WL & H = 1/2WL

* 49M Band Full Wavelength Inverted "L" Antenna
Vertical 55.1 Feet and Horizontal 110.3 Feet with a Total of 165.4 Feet
- - - V = 1/3WL & H = 2/3WL


iwtk ~ RHF
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= = =
= = = (Robert F Wieland) wrote in message ...
In article ,
Telamon wrote:
In article , starman
[snip]

Are all inverted-L's, random wires?

Depends on how you connect it to the radio. With just a single vertical
lead-in then yes but use a coax grounded in some way then no. Another
thing to consider is that the vertical portion should be a significant
portion of the antenna to qualify as an inverted L. An antenna that is
15 feet high and 150 feet long the vertical portion is only 10% of the
total pickup area. I would consider that to be a horizontal random/long
wire.

--
Telamon
Ventura, California

Nothing about antenna theory seems to ever be simple. The antenna you
describe, above about 15MHz, will have a horizontal pattern quite
different from a 150 foot horizontal wire. The horizontal wire will have
a horizontal pattern like the petals of a warped daisy flower, with many
lobes separated by deep nulls, some more than 40dB 'deep'. That
vertical section of the above-described inverted-L will do quite a bit to
fill in those nulls.

Also, the inverted-L is simple to ground. Electromagnetic theory does not
require such a ground, but your friendly local Electrical Code does.

Not saying you're wrong, Telamon; below 10 MHz, you're basically right.
Just saying that we SW & scanner types work with wavelengths from about
one mile down to about a foot, and it's hard to find rules or principles
that apply uniformly across the whole range.