Topband: One wavelength Beverage

[R. Kline]

All of my 5 Beverages are BOG.  The best wire for this is 2 conductor
military field telephone wire.  Each conductor has about half the strands
made from steel and the other half are copper - all suitably plated.  It is
extremely rugged stuff and holds up well.  In Israel, it is occassionally
found in scrapyards where I've bought a kilometer drum of the stuff (new)
for a pittance.  Besides its strength, another nice thing about this wire is
that by shorting the 2 conductors at the far end, it is possible to check
the continuity with an Ohm meter from the feed end.

I don't believe that this is a compromise antenna for terrain such as mine.
My QTH is on a rocky mountain top with very poor soil conductivity. Of
course there is capacitance to ground.  Some of my BOGs are unterminated,
and others are terminated.  Those that are terminated use a 200 ohm resistor
to a quarter wave wire just laying on the ground. I use the 1/4 wave wire
termination because of low ground conductivity and the impossibility to
drive in a ground rod - they always hit underground rocks.  My experience
has been that the unterminated BOGs have excellent F/B. Receiving from the
fed end direction is down at least 2 or 3 s-units.  I can't properly explain
why this is so, but I expect that it is because of the low impedance and
losses. (the usual references predict only about a 3 dB difference). My gut
feeling is that in my particular QTH, there is no significant advantage in
terminating the BOG.

Besides its simplicity, this is a rather stealthy antenna.  From my house
with a small yard, the BOGs go out into the surrounding  public area.  Two
of them cross roads, so I have buried the wire a few inches beneath the
(gravel) road.
I've also buried more extended lengths - about 100 feet in order to hide the
wire from view.

Although a raised Beverage would be more efficient, the BOG is sufficiently
efficient.  They always pass the "acid test" - even when the band is quiet:
When they are disconnected from my FT-1000D, the background noise reduces
significantly. Normally I don't require using my FET preamplifier.  When I
do, the antennas still pass the test.

73,
Riki, 4X4NJ


----- Original Message -----
From: "Herb Schoenbohm" <herbs at vitelcom.net>
To: "Tom Rauch" <w8ji at contesting.com>
Cc: <Cqtestk4xs at aol.com>; <topband at contesting.com>
Sent: Thursday, October 16, 2003 11:35 AM
Subject: Re: Topband: One wavelength Beverage


>
>
> Tom Rauch wrote:
>
> >There is no reason not to use insulated wire except for weight, and no
> >special reason to use it.
> >
> >73 Tom
> >
> >
> I can think of one good reason to use insulated wire such as in a quick
> BOG installation such as used in contests and dxpeditions.  This is the
> practice of running out 500 to 1000 feet of wire just laying on the
> ground, terminated or unterminated.  This is also especially important
> were large fields containing  cows and horses that would render a good
> beverages useless in short order unless it had high enough supports.
>
> Although a BOG installation is not as efficient as the 8 to 10 foot
> elevated beverage they do work well and sometimes make the difference
> between having something or nothing except the TX antenna for
> receiving.  In short my advice is to keep several rolls of insulated #14
> stranded electrical house wire around in the event you need some thing
> up quickly.
>
> 73
>
> Herb Schoenbohm, KV4FZ
>
> >
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> >
> >
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