My TH7 is not as old, 1989 vintage. I haven't tried to get the element
segments apart since I took it down this spring. I never had any trouble
with it, but about 5 years ago I discovered that the boom guy cable,
clamps, and boom to mast bolts were rusting. I had to take the boom off
the mast, but I was able to reach the clamps without taking the antenna
down. Replacing two of the mast clamp bolts would have required
disassembling the transmission line, which I didn't want to do on top of
the tower. It's sitting on sawhorses now, with those rusty bolts still
trapped in there. Should have checked all the hardware with a magnet!
73,
Scott K9MA
On 7/20/2019 21:27, Don wrote:
Interesting. Got my TH7DX in late '82, maybe early '83. Instructions
required the damping rope ONLY in the untrapped elements. I missed
this part when I assembled mine, finally discarded the rope. The
antenna has been up, down, disassembled, up, down, moved, reassembled
and I've never used dampening rope. Do use the end caps except for 2
that were lost a few years back. Always windy here on the coast and
big sustained winds in the winter but have never had an element
failure. The sole issue I've had (besides the really crappy BN-86
balun which was replaced early on) was the use of the cheap plated
screws inside the traps at the coil ends which became a rust ball. I
did replacement with SS and the appropriate conductive grease on the
DE 15M traps (my problem last summer). I need to do the other traps
this summer.
_I am still looking for advice on how to put the antenna element
tubing pieces apart._ I used the grey/silver tubing coating that was
originally supplied with the antenna back when and the tubing to
tubing points are frozen, solid. Have tried a few things but not heat.
Was hoping to pull everything apart last summer for a good overhaul,
but ran into the freeze problem and ran out of time. Fixing the traps
was easy. So someone must have a good suggestion for getting frozen
element tubing apart so it can be cleaned and reassembled.
Don W7WLL
Don W7WLL
On 7/20/2019 6:47 PM, K9MA wrote:
My TH7, assembled according to the manual with ropes and end caps,
was up for almost 30 years, with no failures. I do wish I had noticed
before I put it up that a few of the parts weren't stainless.
73,
Scott K9MA
On 7/20/2019 20:35, Richard Smith wrote:
I believe that the rope in the elements, specifically the element
tips, is particular to the Hy-Gain yagis, at least the 20, 15, and
10 meter designs. I have seen a Hy-Gain yagi, a 5 element 15 meter
yagi, with most of its element tips broken off by regularly
occurring, but not huge, winds. The yagi was built without the rope
in the element tips that is shown in the manual for the antenna.
I replaced the element tips in 1992, with the rope in the tips per
the instructions in the manual, and did not have any element tips
break off during the next 17 years of service at the same location.
Just sharing my experience.
73, Rich, N6KT
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Scott K9MA
k9ma@sdellington.us
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