> BUT -- if you happen to be loading your tower on 80 or 160, you may
> appreciate the additional top loading of elements bonded to the boom.
However, if that is the case, a short wire connected from the center of
the last director and reflector to the boom will provide the desired
connection for top loading on 80/160 without upsetting the element
lengths by introducing odd size sections (mounting plate and boom) in
the element on the beam's operating frequencies.
73,
... Joe, W4TV
On 2014-08-05 2:55 PM, Jim Brown wrote:
On 8/5/2014 11:42 AM, Stan Stockton wrote:
Dan/Hans,
I cannot imagine building another antenna with parasitic elements
mounted to an aluminum plate with the elements electrically connected
to the boom and haven't made one that was connected in over a decade.
FWIW, I don't think you will find an element on any antenna at W3LPL
or K3LR grounded to the boom.
The boom is NOT at ground potential, except at DC. A better way of
describing a connection to the boom is "bonded." Bonding to the boom is
also beneficial for lightning protection.
It is certainly easier to model the antennas if they are floating.
The difficulty in modeling is estimating the effective diameter of the
boom and the mounting plate.
BUT -- if you happen to be loading your tower on 80 or 160, you may
appreciate the additional top loading of elements bonded to the boom. :)
I'm confident that you know all this stuff, but others may not. :)
73, Jim K9YC
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|