This is anecdotal as I have no solid proof of what I think is happening.
It also may not closely resemble your situation, since my tower is shunt
fed.
I have a 100 foot tower with significant top loading that is shunt fed
as a 160m transmitting antenna. I have four two wire reversible
Beverages. The N-S Beverage starts about 50 feet west of the tower;
NE-SW starts about 50 feet west of the tower; E-W starts about 100 feet
southeast of the tower; SE-NW has its midpoint about 80 feet southwest
of the tower.
All of the Beverages show directivity and have allowed me to hear and
work many stations I could not hear without them. However I think they
probably pick up (re-)radiated signals from the tower to some degree.
During heavy rain I often get very strong precipitation static on the
tower. I also hear it on the Beverages. Though much weaker compared to
the tower it is still a few tens of dB above my noise floor on the
Beverages. The Beverages all use insulated wire. I discovered that if I
disconnect the capacitor for the shunt tuning or otherwise modify the
tuning of the tower, the level of precipitation static on all 8 Beverage
directions decreases by at least several dB. This leads me to believe at
least some of the precipitation static I hear on the Beverages is
radiated by the tower.
Note: I have tried "proper" de-tuning or de-resonating methods on this
tower several times through the years, but I don't feel I ever had the
expected level of success getting the tower to stop re-radiating.
73,
Paul N1BUG
On 7/29/21 3:15 AM, RVZ via TowerTalk wrote:
Hi Guys,
I realize "the farther the better", but please advise the minimum recommended distance for a 460'
Beverage mounted 7' above ground from a 130' high self-supporting steel Tower with a 2-element 40m. Yagi top
mounted? Note: the Beverage won't be facing towards the tower. Is the Beverage likely to receive
noise from the Tower with a separation of 100'? Thanks & 73, Dick- K9OMRLVZ@aol.com
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