Topband: [bevantennas] Ground screen under beverage....

[David Olean]

Frank,

That is one of the best e mails about beverages I have seen!! Thanks.  I 
have been toying with making a long Europe beverage along my rocky 
ridgeline. It is solid rock with no way to apply a conventional ground. 
My towers up there have no grounding at the base but utilize multiple #6 
copper wires that extend out about 100-150 ft downhill until they get 
into some dirt. Then they are grounded.  Now to stock up on chicken wire!!

The ground mat under the sloping wire reminds me of G-line that was used 
at L band.

73

Dave K1WHS

On 10/2/2020 1:53 AM, donovanf at erols.com wrote:
> Many years ago I was involved -- peripherally -- with very large phased arrays
> of Beverage antennas installed over very poorly conducting soil (almost
> solid rock) in which ground rods were completely impractical and
> ineffective. The design of these arrays predated the availability of
> general purpose computer-based antenna modelling; however, the designers
> did develop custom method-of-moments software models of the array.
> Importantly their design also involved extensive measurements of
> individual Beverage antenna patterns and Beverage array patterns
> by use of sophisticated airborne sensors.
>
>
> Both ends of every Beverage in the array used fifty foot sloping wires over
> conductive ground mats. Each mat consisted of chicken wire fencing
> material about sixty feet long and ten feet wide. The mats extended about
> ten feet beyond the feed point and termination connections to the mats.
> The mats did NOT extend under the horizontal portion (the antenna portion)
> of each Beverage antenna.
>
>
> The entire array was installed in a secure fenced area with no possibility of
> human or wildlife intrusion. Among other things that allowed antenna
> height of only four feet which resulted in improved front to back ratio and
> reduced sidelobes especially at higher frequencies.
>
>
> The engineer who lead development, testing and evaluation of the array
> explained that the ground mats served two purposes:
>
>
> - substituted for ground rods that couldn't be used in mostly solid rock
>
>
> - almost completely suppressed signals received by the sloping ends of the
> Beverages by making them into efficient transmission lines with very low
> spurious signal leakage compared to a sloping wires over poorly conducting
> soil or vertical wires at each end of a Beverage.
>
>
> 73
> Frank
> W3LPL
>
>
>
>
> ----- Original Message -----
>
> From: "Jim Brown" <jim at audiosystemsgroup.com>
> To: topband at contesting.com
> Sent: Friday, October 2, 2020 3:46:56 AM
> Subject: Re: Topband: [bevantennas] Ground screen under beverage....
>
> On 10/1/2020 5:03 PM, Grant Saviers wrote:
>> Worse than "not the best" or "not a good idea" from prior experimentation.
> And a clear indicator that whoever proposed it failed to learn how
> Beverages work! It all goes back to Mr. Beverage's original patent more
> than a century ago.
>
> Beverages DEPEND on lossy earth beneath them, and DXpeditioners who have
> tried them over high conductivity ground near the sea quickly learned
> that they don't work.
>
> 73, Jim K9YC
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