I think Jerry hit it right on the money.
None of my Beverages are close to, or pointing at/away from, the house. I feed
them with flooded (buryable) RG-6 Commscope CATV coax in lengths up to 600
feet. (I recently purchased a couple of 1000' rolls of that stuff very
inexpensively off eBay.) My Beverages are very, very quiet and hear very well
indeed.
If your house is like mine, it is a prolific generator of RFI: switching
wall-warts, computers and networking equipment, CFL lamps, etc. etc. A Beverage
like the one you describe I is going to pick up a lot of this man-made noise.
The 4th edition of John Devoldere's book "Low Band DXing" has some great info
on Beverages. I strongly recommend it!
It would be interesting to hear what happens if you terminate the Beverage.
73,
Mike Waters
W0BTU
http://picasaweb.google.com/katie65752/BeverageAntenna#
> From: K4SAV <RadioIR@charter.net>
> Subject: Re: Topband: Need to know more about beverages...
> To: topband@contesting.com
> Date: Sunday, January 31, 2010, 2:37 PM
> KA1J wrote:
> > ....
> > Beverage 1 runs from the house to the east and is 500'
> long. The wire
> > comes in through the window sill and is held up by
> branches & it
> > dips,. It has no termination resistor. The matching
> transformer is
> > next to the window. The ground is connected to the
> station ground
> > rod....
> >
> > .....I surely must be doing something wrong.
> >
>
> I wouldn't expect much performance from a Beverage built
> like that. A
> bi-directional Beverage will have a lot more noise than an
> single
> direction one, and connecting the ground to the station
> ground will
> allow all the station ground noise to appear in the
> signal. It could
> also destroy the pattern because of the signal picked up on
> the house
> wiring, which also gets into the output.
>
> Build it like everyone else does, separate ground rods at
> both ends not
> connected to anything else, add termination resistor, use
> transformer
> with good primary to secondary isolation or lots of chokes
> on the feedline.
>
> Jerry, K4SAV
>
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