On 1/23/2012 8:35 PM, RogerN wrote:
About a year ago we (the family) built a digital TV antenna from
instructions on the internet. We put it in the window and it work pretty
good, but the favorite channels are weak, fading/freezing... So with the
money I save getting free TV reception I would like to put up an antenna
tower.
Problem is I don't want to climb a tower or anything like that, at least not
to the part on top trying to wrestle an antenna on a mast. So, with some
inspiration from the army rigging publications on Iggy's website, I thought
perhaps I can make a hinged base for the tower and then stand it up with
rigging techniques. Maybe if I use 4 guy wires instead of 3, 2 could be in
line with the hinge axis, the rear one would be set the calculated length to
tighten up when the tower is somewhat vertical, and the 4th guy wire would
be left long to pull the tower up. Perhaps something to level the load and
pull the tower up straight, trying to prevent bending loads.
Another possibility inspired by the rigging manual would be to construct a
long (maybe 50 feet), light duty (wooden?) boom, pull the boom up, steady
with guy wires, and use it like a crane with block and tackle to lift the
antenna tower. This would eliminate the need for the hinged tower as the
boom would be able to lift the tower and I could lower it onto the base.
An offshoot of this idea would be to set up a sturdy timber that could be
used with block and tackle, hoist, or similar that would be able to lift all
the load I would want in my Ford Ranger truck. A pole is tempting since one
pole with guy wires would be able to handle most of my machinery. An
alternate idea is to construct an A-Frame, possibly wood, that I can use
with a hoist to lift anything I would want in or out of my truck.
Looking for info on Homemade cranes I came across this one that looked neat
for what it is:
http://www.youtube.com/watch?v=bq4H1y9MOpQ
The rigging manual ideas can be adapted to rig some handy shop cranes for
lifting our heavy toys. Might even be able to make a pickup truck crane
with a wooden boom, a hoist to control the angle of the boom, and a winch to
lift. Harbor freight already sells something like this, It could probably
have more lifting capacity at the extended positions with a come-a-long
taking some of the load off the end. Could come in handy at auctions... I
guess Iggy can just trailer his forklift to the auctions, but for the rest
of us poor folk....
RogerN
You are trying too hard to get the antenna up higher. What leads you to
believe the reception will be better with the antenna up there? Digital
and analog use the same UHF frequencies so why a "digital" antenna?
If you are sure you want higher, use a 40 or 50ft push up mast. each
section being 10 ft, only 1 foot is overlapping.
Set up the fully nested masts with guying at the 10 ft level, using 3
guy wires and good ground anchors. Adjust until the set is exactly
vertical. Then attach the antenna to the top of the top mast, and/or
attach the antenna rotator. Then attach three guy wires to each of the
remaining sections guy rings while the set is still nested. Use a step
ladder to reach the mast tops.
Then climb up the step ladder so you can pull up the innermost/top
section and lock in place with a cross pin in the matching hole of the
next larger section.
Then do the same with the next larger section, and then again with the
next one. If the very first section is properly guyed and is exactly
vertical, the whole thing will stand by itself.
Then begin attaching each of the guy wires to the same ground anchors,
or other anchors, if you wish. Adjust each set so the mast remains vertical.
In about an hour, you can have the whole thing all set up. Next time you
can do it an half the time.
Paul