R: [TowerTalk] 160M Wire Antenna

[Maurizio Panicara]

The assumption a relatively low (90 Ft) horizontal antenna can be a decent
one for 160m DX is true when referred to people who have not the room for
large vertical/s (arrays) neither the space required for a set of separate
receiving antennas or when comparing to the efficiency of short loaded
verticals (expecially when roof mounted) that on 160m is so low to look like
a dummy load at any of the useful angles.
A symple quarter wave vertical radiator is definitely outperforming any
single horizontal dipole at 1/4 wavelenght from ground and also one at 1/2
wavelenght.
The above happens, anyway, when the very low angles of the vertical antenna
are present (a very good ground plane is required), the used power is enough
to compensate the attenuation caused by the long travel through the D layer
in the ionosphere and a set of 6x2 wavelenght long beverages are used to
receive.
It's same evident that a quarter wave GP on 160m requires a very tall
structure, a large ground plane, and suffers if tall buildings are
sorrounding it. (not counting for TVI and BCI problems if someone lives
inside that buildings)
Without separate antennas for receiving (or other phased verticals to obtain
a pattern) a GP is mostly a fair DX machine under the receiving, expecially
in the SSB traffic were a bigger S/N is required and the receiver filter
can't be so narrow like on CW.
Althoug beeing a contester myself, a "state of the art" 160m antenna farm
can't apply very much when the problem is what to use as a 160m antenna in a
constrained situation.

73,
Mauri I4JMY

----- Original Message -----
From: <i4jmy@iol.it>
To: <towertalk@contesting.com>; <w7why@juno.com>; <alwilliams@olywa.net>
Sent: Friday, April 21, 2000 5:05 PM
Subject: Re: [TowerTalk] 160M Wire Antenna


>
> The 1/4 wavelenght height from ground is definitely not the best
> possible but already not so bad when other choices are unavailable.
> Considering that the minimal take off angle for 160m is not so low as
> with other bands and the peculiar angle conditions at sunrise/sunset ,
> I wouldn't be surprised if an acceptable DX traffic is also obtainable
> with an efficient horizontal antenna at 1/4 wavelenght from ground.
>
> 73,
> Mauri I4JMY
>




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