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[TowerTalk] Need help identifying an old tri-bander

To: Tower Talk <>
Subject: [TowerTalk] Need help identifying an old tri-bander
From: N6FD <>
Date: Sun, 16 Jan 2011 20:05:15 -0800
List-post: <">>
I bought a tri-bander used from a silent key's estate.  His wife did not 
have any documentation for the antenna.  Given the state of the antenna 
and the tower that I got with it, it was probably put up some time in 
the 70's or 80's.  No markings have survived on the antenna. The 
following are the details of the antenna.  I don't have the original 
spacing between the elements.

Boom length:  278 inches, in three sections
Reflector: 382 inches with one set of traps
Driven element:  317 inches with two sets of traps, center insulated, 
fed with balun
Director 1:  209 inches, no traps
Director 2:  293 inches with two sets of traps

Elements are mounted on rectangular aluminum plates, these are attached 
to the boom with U-bolts.  Element sections taper out from the boom.  
Each section is attached by slit tubing and a clamp.  The clamps are 
galvanized steel sheet metal with the clamp nut secured by a small tab 
of the clamp.  The clamp screws are perpendicular to the element.

The traps have covers that appear to be fiberglass with plastic end caps 
(disintegrating in the environment).  The trap cover has a small weep 
hole in it.  The trap coil is bare aluminum wire secured to the 
fiberglass insulator at each end with a screw.  The wire is covered and 
held in place with a thick black paint.  The 10M trap is 10 turns space 
wound 1 wire diameter apart.  The 15M trap is 16 turns.  The reflector 
has only the 15M trap.

The driven element is a dipole with a phenolic center insulator.  This 
is clamped to the boom adaptor plate with a couple of U-bolts.  I have 
not had a chance to check the performance of the balun yet.

If anybody knows what this antenna might be, and where to get a manual, 
please let me know.  I will try to get some pictures up tomorrow to help 

73, Erich


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