Higher is better. The current elevation (18 feet) is probably sufficient
for operation on 20 meters. Moving up to 36 feet will improve operation on
40 meters significantly. I like to have a dipole up 1/2 wavelength above
ground.
Keith NM5G
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com] On Behalf Of Derek Cohn/WB0TUA
Sent: Tuesday, October 26, 2004 11:45 PM
To: towertalk@contesting.com
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.
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
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
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|