This is very interesting stuff Patrick. Thanks for sharing.
73's
NJ0F
-----Original Message-----
From: Patrick Greenlee
Sent: Wednesday, December 16, 2015 8:12 AM
To: towertalk@contesting.com
Subject: Re: [TowerTalk] WTB Rohn 25G tower insulator
For those among us not initiated in oil field terminology... Sucker rods
are the vertical tension members connecting the Texas Grasshoppers
(Pumpjack) to the underground pump. These are fitted with threaded
terminations so that several can be placed in series. Steel is a typical
material but fiberglass is also used. This from Wikipedia ==> "Sucker
rods are also commonly available made of fiberglass in 37 1/2 foot
lengths and diameters of 3/4, 7/8, 1, and 1 1/4 inch. These are
terminated in metallic threaded ends, female at one end and male at the
other."
These fiberglass rods are very strong, available inexpensively on the
used market (in areas with oil fields such as OKC and Midland Texas),
and can be used for various antenna parts including insulators.
This will give the engineering specs ==>
http://www.fiberglasssuckerrods.com/technical-data.html
The threaded terminations make it easy to transition to steel should
that be desired or to connect rods in series, as when used for their
original purpose. One of these "pulltruded" fiberglass rods cut into
several shorter lengths could be used to insulate a tower. For example,
groups of these could be used for each tower leg.
The balun in my OCF dipole (90ft X 180ft) is supported by a vertical
fiberglass sucker rod and in turn supports the OCF dipole wires. I have
a 2 3/8 inch pipe 24 ft long vertical lashed to a small oak tree. the
sucker rod protrudes from the top of the pipe about another 18 ft. This
allows the vertical component of the OCF dipole (Carolina Windom) to not
run parallel to a conductor.
I can buy these 37.5 foot units 1 inch diameter in single lots at $20
and in volume they go for $8 but shipping is the sticking point for
large quantities out of the Midland Texas area (where my OKC source gets
theirs.)
These are cut into lengths and used as fence posts that never rust or
rot. These rods could be used for various applications where strong
non-conductive structure is needed.
Patrick NJ5G
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