A Builders Transit is the only tool that can properly plumb a vertical
structure. Any wind or slight convection will make a plumb bob useless.
My 100' Rohn 80 tower on sloping ground was plumbed as best possible
using a plumb bob, 8' level (while climbing up and down), the horizon,
and eyes, and we thought it was pretty good. The only clue that
something wasn't right was that the guys on one side sounded different,
duller, when tapped sharply with a wrench. This turned out to be the
down side.
When I brought a Transit home from the pawn shop, I was shocked to find
the tower over 2' out from vertical, necessitating two new big grips.
Luckily we had left the guy wire ends trimmed long to loop through the
turnbuckles.
Using a transit is easy. There are two bubble levels that must be
centered using adjusting screws, and then the crosshairs should ride
right up a tower leg or the center of a pole as you elevate the
telescope.
The only thing that makes adjusting guys with a transit time consuming
is having to move the transit between two locations. Two transits would
make it a very quick job.
I see used transits readily available now that surveyors and engineers
are using laser and gps equipment. Check your local rental or survey
equipment supplier for used gear.
Aloha,
Jonathan KH6X
kalepa@maui.net
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