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Old October 5th 06, 11:32 PM posted to rec.radio.shortwave
[email protected] r2000swler@hotmail.com is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 285
Default More loop comments

I may have given the impression that I think that loops have no place
in a radio system.

I am also a ham, extra class, and for the last 18 months I have been
somewhat active
using NVIS in a mobile setup. When you are using a 1991 Honda roof as
your ground
plane, a loop is the only thing that works.

My negative comments about loops should be for broad band, untuned
loops.

My SWL mainly is utility and I often have 2 receivers tuned to very
different frequencies.
For my SWL activities an antenna that must be tuned is not very useful.

A friend pointed out that I had tared all loops with the same brush.

I will stand by the observation that in all of my tests, small,
fractional wavelength
loops have no advantage over, and have proven very inferrior to the
Lankford active
dipole. Even a north country configured in a dipole array worked better
then the Wellbrook.

I will be the first to admit that I have not experimented with larger
loops for broad band
SWL reception. If I every get the time it would be interesting to use a
Dallas "ultra linear"
amplifer with a 50' square horizontal loop. For the time being I will
concentrate my energy
on standard "long" wire antennas with a set of 2 vertical Lankford
active dipoles couple to a
phaser with an additional and rotatable horizontal active dipole. That
should cover my
foreseeable needs.

A Langford "ultra linear amp" makes a very good buffer for ampifing a
signal prior to
power division. In fact it works better, as in much higher IP2, IP3
and simple harmonic
distortion then the 40 year old Nuvistor based unit I had been using
for the last year or
so.

FWIW we got the desk in place, stained and sealed between showers
today. And I
was able to burry the copper tubing that will cary the coax away from
our home. You
can't have too good a ground. The entry bulkhead is ready to mount, and
I am only a
week behind on my planed timeline.

Terry