> Whether or not the unused slopers act as a counterpoise or not depends
> on the switching arrangement. If they are 'floating free', then you
> are right; however, if the unused slopers are electrically grounded to
> the tower at their 'feedpoints', then they DO act as 'counterpoises'
> [in reality, they are part of the 'tower side' of the sloper system].
Actually it is very difficult to not couple the unused slopers to the
tower, because they are very close to the tower.
I certain agree they they MIGHT not have been coupled at all, but
the likelihood they are totally isolated is nearly zero.
> I used a 'sloper' system like this before they were called 'slopers'
> .. used the guywires for my tower, insulated at top and bottom, as a
> 4-wire array, with remote relay selection of any one or two of them as
> radiators. Using one gave me a 'sloper' system, with the other three
> 'grounded' to the tower, and using two of them gave me an 'inverted-V'
> configuration.
That's how I would do it. I sure wouldn't leave the unused wires
floating for lightning and other reasons!
I actually was planning a system like that for 160, but the gain
figures in modelling made me abandon the idea.
73, Tom W8JI
W8JI@contesting.com
________________________________________________________________________
This list is sponsored by the new eHam.net Store. When you buy products
like ICE filters, Array Solutions StackMatch, or M-Squared Antennas from
the eHam Store for the same price you pay direct, a portion of the sale
price goes to support this list. Check it out at http://www.eham.net.
-----
FAQ on WWW: http://www.contesting.com/FAQ/towertalk
Submissions: towertalk@contesting.com
Administrative requests: towertalk-REQUEST@contesting.com
Problems: owner-towertalk@contesting.com
|