Topband: 2 Parallel Beverages

[ZR]

----- Original Message ----- 
From: "Mike Waters" <mikewate at gmail.com>
To: "topband" <topband at contesting.com>
Sent: Wednesday, May 23, 2012 4:19 PM
Subject: Re: Topband: 2 Parallel Beverages


> There's just one possible issue about all this that is conspicuous by its
> absence, as they say. At least in some installations, having feedlines
> going to each end of the Beverage supports is going to require laying the
> coax on the ground under nearly the entire length of the Beverage.


It can be placed parallel but a few feet away also.


>
> And that's not the best situation, as it has been shown that we really 
> need
> lossy earth under our Beverages for optimum results. Just look at all the
> people who got disappointing results from following that bad advice 
> Misek's
> Beverage handbook about laying a wire on the ground underneath the
> Beverage.


Yeah,and Misek lives about 2 miles away but I never hear him on the air. 
Anyway that was the first Beverage book I bought and quickly discounted it 
when nothing worked very well....including the parallel wire.


OTOH a coax running under the antenna should have no to minimal effect IF:
1. A transformer configuration is used and not an autotransformer. Winding 
for minimum winding to winding C and high isolation is a given for best F/B.
2. The feed line ground is done about 20-30' away from the antenna ground 
AND decoupled by beads at the transformer and just after the ground and at 
the house plus another ground rod there if necessary. This holds even for 
feeds going off at right angles.
3. The feedline is 20-30' away from the antenna groundrod and all its 
radials.

Since the feed is not directly connected end to end to the 2 Beverage rods 
it should be invisible.



> Or the people who have unsuccessfully tried running a Beverage
> across a field of buried radials, or where --unknown to them-- there was a
> buried pipe, conductor, etc. under the antenna. It screws up the F/B ratio
> and pattern, to some extent.


Ive run them on the ground under elevated radials with no apparent harm. My 
SW/NE Beverage actually travels under those radials, is still as quiet as 
expected and shows excellent F/B.


>
> I am in favor of doing it all from one end; heck, all we need to do that 
> is
> just one more transformer. We have to build two anyway; why not just wind 
> a
> third one --the reflection transformer-- while we're at it?


Agreed. Its really the effort made to build a reliable system no matter how 
it is fed that counts. Hammy Hambone construction is the last thing wanted 
here because it WILL bite you when least wanted....Murphy's Second Law.

Carl
KM1H


> It's simply not difficult at all to build a bi-directional Beverage fed
> from one end. http://www.w0btu.com/Beverage_antennas.html clearly shows
> both ways of doing it, either with or without remote relays.
>
> 73, Mike
> www.w0btu.com
> _______________________________________________
> UR RST IS ... ... ..9 QSB QSB - hw? BK
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