[TowerTalk] telephone pole as tower

[Ken Hirschberg]

Hello all-
Yes, a phone pole is quite feasible and has advantages and disadvantages
compared with a tower as follows:

Advantages:  1.)  Cost: A class 2, 70 ft pole will run about $2500
installed. It requires no guy wire.  A self supporting 60 ft. tower costs
about $8000 installed. This is for a premium tower, which is still not quite
the support that a pole is in my opinion.  A properly installed, treated
pole will, in most cases, outlive the installer.   2.)  Appearance:  It's
just another pole among many in the area.  City planners that I talked to
before installing a pole preferred the pole over a tower.  Properly
installed, there are no hanging wires, etc., giving a most uncluttered,
non-glare appearance.

Disadvantages:  1.)  In general, a pole requires access to within about 40
ft. or less, by a large crane for installation.  Lifting a pole over a house
is not a problem if the crane is tall enough.  2.)   Special attention has
to be paid to lightning protection; however, this can and should be combined
with downlead protection, and is somthing that is also useful for shunt
loading, slopers, etc..   Example:  Copper pipe or metal conduit, bonded to
both the top rotor assy. and to a  ground plate that is put into the bottom
of the hole for the pole. (this in addition to other, conventional
grounding)  3.)  A pole requires a bolt-on rotor mounting assembly to tie
the top of the pole to the antennas.  Mine, made for a large, single-boom
beam, was a 7 foot long piece of very heavy aluminum channel, with a large
reinforced shelf for the  rotor and two smaller shelves for each of two
thrust bearings. As on my current antenna, you can get away with two thrust
bearings if the rotator is not rigidly mounted.  Mine is on a plate that is
in turn mounted on another plate using 6 auto engine mounts.  The channel
was mounted to the pole with mounting plates, gain plates, and other
pole-line hardware(the real stuff, NOT the hardware-store stuff)
Additionally,  two sets of sway braces stabilized the rotor assy.  Expect a
cost of about $600 for the rotor mount assy..  4.)  A pole does require a
rather deep hole.  In most places, a bobcat can do this in a short time, or
you can dig it by hand as I did. (good excersise!)  Trimming shovels and
spoon shovels with 12 ft. handles are available.  I used a 12' trimming
shovel and an 8" dia. post hole auger with extensions.

I would recommend a class 2 or larger pole;  the EPRI gudeline for pole hole
depth is as follows:
10% of the pole length plus 2 ft.  This is for average soil strength.  My 70
foot pole was  10 ft. down, set on and in pea gravel in a 20" diameter hole.

My current tower is guyed Rohn 55G,  which I like very much, but which is a
TOY compared to my dear old pole;  I'd have a pole today if I didn't live on
solid rock!  There is much more to tell about poles, but it would be
excessive bandwidth to say it all here.

Regards, Ken Hirschberg,  K6HPX


Fields, Bryan wrote:

> Hi all!!
>
> Could I have you opinions as to using a telephone pole for a tower.
>
> The height or the pole is 50', with another 10 ' in the ground and, it
> is approximately 3 to 4 feet wide at the bottom.  It will be supporting
> a rotor, 22 element 70 cm beam, 15 element 2m beam, and a 2m 70 cm
> vertical.
>
> Does anyone have any idea if this is feasible and if so does more of the
> pole need to be in the ground.
>
> Thank you
>
> Bryan Fields, KB9MCI
>
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