[TowerTalk] Overhead Dipole = Lightning Protection?

doc kd4e at verizon.net
Wed Jul 7 23:19:37 EDT 2004


Considering the observations below we have yet another real
good justification for that dipole we'd like to sling over
the house or across the patio from tower to tree ... "But
Honey, it's a lightning protection device."

Seriously, I can see a doublet strung from the planned
location of my tower to a really tall pine tree on the
other side of the house.  The doublet would be about 10
feet West of the back of the house, the feedline could
droop back toward the tower (I know, not a pure right-
angle departure from the feedpoint), and then pass through
a remote tuner or balun and through Polyphaser device
mounted near the base of the well-grounded tower afterwards
following the rest of the cables to the entry panel and
then into the radio room.

Hmmm.  This could work!

73, doc kd4e

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http://www.lightningsafety.com/nlsi_lhm/InstallRods.html

4. OPTIONS FOR CONSIDERATION

According to local situations, the following alternatives to ordinary 
lightning rods may be useful:

     (a) The electric power industry has adopted designs of tall masts 
or overhead grounded shield wires located above the structure to be 
protected. This can be observed on most high voltage power lines and on 
most distribution and substations. Here, the idea is to collect the 
lightning ABOVE the structure, not directly on it.

(b) Following is from US Air Force AFI 32-1065, section 14.5, p. 10 
"Explosives Facilities …that do not use structural steel as air 
terminals must use either a mast system or an overhead wire system. 
Since these systems provide better protection, and maintenance is 
easier, consider using this type of protection for other kinds of 
facilities."


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