[Antennas] Fold Over Pole

[Jim Hill]

Rick: I queried the group about vertical antennas earlier this year, and 
one of those responding had an interesting web site telling how to use a 
gin pole to raise a 90' vertical. While it is a much more ambitious setup, 
there's good info there. See http://www.n6rk.com/irrigation.html
73's Jim

At 04:14 PM 6/9/2002 -0400, you wrote:
>At 01:49 PM 6/9/2002 -0500, Richard Biddle wrote:
>>Once upon a time I had some plans for a good reliable fold over antenna
>>pole.  I want to put up a small set of VHF/UHF beams and a CD44 rotator at
>>40 foot or so.   I have access to free pipe and a gentleman who welds for a
>>living.  I can't find my plans ...
>
>Richard:
>
>I've had a foldover of my design planted for several years now.  It is 
>quite a simple project actually.  Not quite the 40' you've stated, but 
>close; my 22 element 2M and 40 element 70cm antennas, with a Yaesu az/el 
>rotator have stood the test of time in stormy SW FL.
>
>I built the entire tower on the ground, dug the hole, and had several hams 
>wrestle the 300 pound monster into the ground, where it was cribbed with 
>2x4s and stakes, while 600 bs of concrete cured for a week.
>
>The tower is comprised of 3 4x4s around 22' in length.  Two of them are 
>planted in the ground 3 feet, while the third pivots from near the top of 
>the stationary posts, on a stout stainless bolt, washers, and double 
>nuts.  A similar "pin" is pounded through all three and washer and nut 
>placed to hold the tower from folding.
>
>A 20' length of 2" schedule 80 galvanized pipe is mounted to the center 
>timber and gives additional height.  A large eye bolt is fastened through 
>the bottom of the center timber to hold a counterweight used when the 
>tower is lowered.  I bent some rerod into a loop and put it in a 5 gallon 
>bucked sprayed with Pam.  When the concrete set, it pulled out of the 
>bucket with ease.
>
>So standing in front of the tower, it looks like this:
>
>         Two 4x4s set 3 feet into the ground, standing 19 feet high.  A 
> middle timber is pinned between the 2 stationary timber at about the 3" 
> level, and again at the 17" level as the foldover pivot..  The middle 
> timber sticks above the 2 stationary ones by about  6 feet, putting it at 
> around 25'.
>
>         The 2" pipe is fastened to the middle timber with 3 large 
> stainless bolts, washers, nuts, 90 degrees to the pivot.  The pipe sticks 
> up about 10 feet above the middle timber, to about 35'.
>
>         A large eye bold is fastened through one of the stationary 
> timbers to thread a rope for lowering the tower.
>
>To lower the antennas/rotator, I fasten the counterweight with a short 
>piece of rope to the eye bolt on the movable timber.  I fasten a long 
>stout rope around the 2 stationary timbers, through the stationary eye 
>bolt and to the same eye bolt as the counterweight is attached.
>
>I remove the lower pin by removing the nut and washer, and pounding it 
>through with a similar bolt.  You definitely want a snug fit on this pin 
>and the pivot bolt.  I pay out the line while watching the antennas and 
>having someone inside manipulate the rotor control.
>
>It works great, but if I ever build another one, I will substitute one of 
>those reconditioned Rohn push up poles you see at the hamfests for the 
>entire center timber/pipe assembly, and let it pivot between the 
>stationary 4x4s.
>
>One of the hardest things I've found is finding the position on my 
>horizontal mast that equates to the antennas being level, once I hoist 
>them back into the air.
>
>I used to use a come-along to hoist the tower back into position.  This 
>took at least half an hour and caused me to go through several tiresome 
>machinations.  I now fasten the rope to my trailer hitch and "drive" the 
>tower back to the vertical.
>
>I hope this is of some help.  I make no warranty as to the suitability of 
>this design for your application, but has helped me to work over 100 
>countries, as well as MIR with my Oscar station.
>
>73, Mike kf4fdj
>
>- - -
>Your moderator for this list is:
>Larry Wilson KE1HZ antennas-owner@mailman.qth.net
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