Howdy Mike,
Well, I am grateful for the 2 nulls as there is little or no activity in
those directions thus making for some gain in the favored directions (
NE-SW ) and lowering noise from the sides...
As far as lowering the R of this loop, I plan soon to parallel the loop with
a second one tuned in the near field, that outta run the 'R' down some
more...
In the meanwhile an e-probe way out in the woods helps to cancel some
residual noise...
In the LowFer days 160-180 khz. I found that the AC neutral was a decent
enuf ground.
The idea of having above ground radials with an inductance in series with
their common point makes for lower looses as well, but then again, one
allows the local 'E' field to become part of the 'loop' while a complete
loop shunts the local E fields and produces far less lethan voltages..
Gudday from Dave @ WD2XSH/17
----- Original Message -----
From: "Mike Dennison" <[email protected]>
To: <[email protected]>
Sent: Friday, February 27, 2009 1:14 PM
Subject: Re: LF: Re: LF Antennas - back to basics
Dave Riley write about loop antennas:
As for the CONS, well I just don't think of any... Somebody??
There are two 'cons' that I can think of. One is the weight of the
low-loss wire required. This would cause a problem in my own case as
local restrictions lead me to use a fairly fragile mast. The other is
directivity in the form of two sharp nulls.
I have used a loop in the past and for a short while held the 73kHz
distance record using it. However, after some comparitive tests, I
opted for a Marconi which at that frequency had similar 'gain' but
was almost omnidirectional.
In all other respects you are, of course, right.
Mike, G3XDV
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