Had to take antenna down because of landlord.
37 foot Telescoping Mast originally designed to support a 10-80 meter
inverted-V, but could be used to support a small rotor and beam
(28mhz up to vhf/uhf).
Material used is schedule 80 PVC Tubing, in 4 sections, with O.D's:
3.50", 2.75", 2.25", and 1.75". The sections are held in place by a
u-clamp and thru center eye-bolt arrangement. Each u-clamp has 2
outer eye-bolts, along with the thru center eye-bolt, which are used
as guy points.
The bottom 3 sections use PVC sched 80 reduction union joints (very
beefy) which I reamed out to allow upper sections to slide thru
freely. The three over-lapping sections are over lapped by 12, 16,
and 18 inches, from smallest to largest dia., respectively. Each
upper section has 2 sets of 3 spacer bearings that take up the
excess play inside each over-lapping section.
As you may well have gathered, I have an Engineering background
and took some time designing this Telescoping Mast. It wasn't
something I just threw together.
The last 2 years in San Jose, CA, has brought storms with winds as
high as 75 mph. This Mast barely moved during these storms. Also, I
use three sets of guys which are marine-type nylon rope that is UV
resistant.
Mast is more durable and can withstand higher wind speeds than
a steel mast, when guyed properly. Also, Mast doesn't interact
with antenna like a steel mast would.
73,
-gary
ke6byu