Hello Ron:
I have a base insulated 120 foot tower that acts as the driven element in my
3 element vertical Yagi antenna (switchable in 4 directions). See the ON4UN
Low band book for details (last 3 editions). AA1K, VE3EJ and others have
this antenna too. My tower is a solid leg tower so I used JetLube SS30 at
each tower junction and the there is a welded solid #2 wire going between
each leg junction (all 3 legs) at each section junction. This is what is
done in AM broadcast installations. You may not be able to weld (I used
Cadweld) to the small pipe (hollow) legs on Rohn 25. I would consult with
Rohn and a professional welder.
I do not like having just a thimble that the preform sits in going to the
guy bracket. It is a good mechanical connection however it may cause noise
as it is not firmly bonded and there is 3 feet of preform on this. I use the
bent pin shackle with a D504 insulator - then the Phillystran preform.
Operation here has been flawless.
Be safe
73
Tim K3LR
-----Original Message-----
From: Topband [mailto:topband-bounces+k3lr=k3lr.com@contesting.com] On
Behalf Of Ron WV4P
Sent: Tuesday, August 18, 2020 2:06 PM
To: 160
Subject: Topband: Rohn 25 Vertical questions.
Howdy All,
I'm getting ready to put up a Rohn 25 Insulated Base ~1/4 wave vertical.
(115') and I'd like to get some advice if possible.
I'm using guy brackets. Any reason to use Insulators between the Big Grips
/ Phillystran and the brackets like is recommended on higher bands ?
Any preferred goo or concoction to put on the tower sections before joining
them ? Or nothing ?
Any other advice on the tower / radiator itself from folks that have BTDT ?
My plan is 115' and I'm using a Rocket Top at the top. Without any mast I
will have my 115' but I plan to insert a mast into the rocket top (8') and
have it Inside the tower, not extended above the top. I figure if it
resonates too high I have 8' to play with up top.
Thanks, Ron, WV4P
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