Topband: Base Insulator for Rohn-25

Dick and Adele Bingham binghamstehekin at
Sun Sep 10 02:55:23 EDT 2006

Regarding ===>
Message: 2
Date: Fri, 8 Sep 2006 18:39:54 -0700 (PDT)
From: Michael Rauh <mikerauh at>
Subject: Topband:  Base Insulators for Verticals


  I have been checking out insulators for Rohn 25G.  Here is what I have

  1.  Array Solutions - Delrin insulators.  $1145 for a set of three.  The
$250 solution is no longer on the website.

  2.  K0XG - Insulator Adapters.  $115 each, insulator included.  According
to Rich, they are rated to 150 feet of 25G tower.  Rich also says he has an
insulator that mounts under the base plate.

  3. WB0W - A set of three for $399.  I have ordered a set.  They should
arrive by the end of the month.  I have one of Gaylen's gin poles, it is
built like a tank.  If his insulators are up to the same standard, they
should be bullet-proof.  I don't think these parts are on his website yet.
Send him an email.

  Good luck with your antenna project.

  Mike, W8GT

I insulated my stack of Rohn 25G by drilling three holes in a BP-25 hinged

The holes were in a triangular pattern - two were located near the corners
on one side and half-way between the corners on the opposite side of the
BP. Each hole was about 3/4" in diameter.

I machined three "shoulder-washers" from some phenolic stock that were
later inserted into the holes drilled into the BP-25. Next, I stacked
several pieces of PVC sheet stock (~1/4" thick) together - side dimensions
were slightly larger than the BP-25 sides - and drilled three holes thru
the PVC plates using the washer/BP-25 combination as drill guide.

Next, I assembled onto three J-bolts one nut and one flat-washer. Each
J-bolt was then pushed from the bottom side of the PVC insulator stack thru
the holes
in the BP-25 and then followed by the phenolic washer, another flat-washer
and finally a lock-washer and nut.

This assembly, when pressed into fresh concrete and leveled becomes the
tower base. Once the concrete has cured the tower can be erected. I
operated this system at 1KW (SB-220 amp) and never had a failure of any


Dick - w7wkr  CN98pi

I choose Polesoft Lockspam to fight spam, and you?

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