I would think the on-concrete mount would work but you'll have to guy the
4x4.
Losing 4' of the height is not too big a deal for the theoretical
performance gain or loss you will experience. Putting the 4x4 in the ground
and in concrete should make a nice strong support.
Since you're trying to get every foot of height you can, you might want to
consider the old ARRL Handbook (or was it ARRL Antenna Book?) style of
support, where you add to the 4x4 in the ground a pair of 4x4s bolted
outside it, then another one bolted inside those two to get a lot more
height. And, if done right, maybe even using a boat winch, you can tilt it
over. With that sort of system and your fiberglass mast you could get up
pretty high.
73 - Rich, KE3Q
----- Original Message -----
From: "Derek Cohn/WB0TUA" <vibroplex@mindspring.com>
To: <towertalk@contesting.com>
Sent: Wednesday, October 27, 2004 12:45 AM
Subject: [TowerTalk] Mounting a 4x4 in concrete
Dear All,
I'm trying to elevate my very low dipole that is fed with balanced line.
I'm trying to go with a non-metallic support so the balanced line does not
interact. My dipole is currently 18' in the air.
I recently purchased a 22' fiberglass mast from The Mast Co. This is their
heavy duty windsock pole. I'm planning on mounting it to a 20' redwood 4x4
with the Kwik-Block mounting blocks they also sold me. I plan to set the 4
x4 in concrete.
I checked around and one of the local deck builders says I need to put about
4' of the redwood 4x4 into the concrete. That would reduce my effective
height of the 4x4 to 16'. If I overlap the fiberglass mast a foot or two, I
have 16' + 20' = 36' which is roughly double the height I have now.
What do you guys think about the 4' of 4x4 into the ground. Too much, too
little, just right? I noticed that you can put l-bolts into the concrete
footer and mount a u-shaped bracket on top of the footer that will accept
the 4x4. This is advertised for deck applications and I think it wouldn't
support 20 feet of 4x4. However, it would give me four more feet of height
if it could be made to work. Has anyone tried this?
73,
Derek Cohn
Morse Telegraph Club - Alton Chapter
Telegraph Office UD, sine DJ
Amateur Radio Station - WB0TUA
1969 M274A5 Mechanical Mule
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.
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_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
_______________________________________________
TowerTalk mailing list
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