Align by sight?
Ever hear of a level?
When I first got back on the air, I used a TH7 for about 2 years. When I put
that antenna back together (I had it stored in my garage), I bolted the boom to
my tower, about 3 feet off the ground. I used temporary ropes to hold up the
ends of the boom, and leveled the boom - with a level.
For the elements, I cut two 2 inch "thick" pieces of 2X4- exactly the same
thickness. Not 2 1/8". Not 2 1/16". Exactly the same. Tape each piece to
each end of the level. Now you can place the level across the boom / boom to
element clamp, and level each element.
IMO, the problem with the Hy-gain clamshell is the center bolt with the square
nut which is supposed to hold the elements level. With my TH7, after the
element was level I drilled a hole through the hole and through the boom and
used a stainless steel bolt with two flat washers (one on top and one on the
bottom), a lock washer and a nut. OMG, I did something most people here will
consider scandalous.
IMO, the "worst" element to boom mounting is the Cushcraft. Cheap U bolts,
thin aluminum tubing.
Tom, N2SR
On Wednesday, July 25, 2018, 10:17:32 PM EDT, Jim Thomson
<jim.thom@telus.net> wrote:
Date: Wed, 25 Jul 2018 14:59:30 -0400
From: rlvz@aol.com
To: towertalk@contesting.com
Subject: [TowerTalk] 5 Band Yagi with more than 2 elements per band
<But don't the JK antennas use muffler type clamps for attaching the elements
to the boom where the elements must be lined up by sight?? I hate fooling
around aligning elements by sight only to have them change when you tighten the
clamp.??Pre-<drilled element brackets are much nicer and my idea of a well
designed antenna.
<73,
<Dick- K9OM
## Nope, JK uses massive machined aluminum 2 piece wide clamps, with loads
of surface area. Muffler style clamps are history these days, good riddance...
they have virtually zero surface area.
But I know what you mean by the oem F12 boom to ele brackets, saves a bunch
of time. Flip side is... IF the yagi is needed to be re-tweaked, and ele
spacing adjusted, it’s a gong show with the F12 style brackets..esp aligning
them.
There is zero room for error. They must be drilled precisely.
## For a real horror show, the hy gain cast, clamshell style.. boom to ele
clamps, I found, were a bitch to align properly. One could spend a long time
aligning a TH-11. IMO, the worst designed boom to ele clamps bar none.
Jim VE7RF
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