berkeman said:
If the fulcrum and ground supports can tolerate the extra weight of a counterweight at the bottom of the antenna mast, that would seem to be a big improvement in the forces required to raise (and lower) the mast...
The extra weight of counterweights would be more than compensated by a lower tension requirement in the winch wire, so the fulcrum and support stand must be built very strong in the first place, especially if it has no counterweights.
I'll describe a picture I have in my mind.
One pintle bar could be attached across the mast tube at the fulcrum, or there could be two pintles, welded externally either side of the outer tube.
A strong-back tension bar or rod, offset about 6” at the fulcrum, ends attached at the bottom of the mast and 5 feet above the fulcrum, would prevent the outer mast tube bending at the critical pintle weld while tilting.
Near the top of the stand would be two U-shaped journals to support the mast pintles.
The winch would first be used to raise the mast fulcrum, to place the pintles in the journals. That would need a temporary short jury pole at the top of the stand above the journals.
A bolt would pass through the top of each 'U' journal, above the pintle, to prevent a pintle lifting out of it's journal in a cross-wind, or during some unfortunate tilting upset.
Near the bottom of the mast, a horizontal round cross-bar could carry flat weights on each side to counter-balance the mast.
How will an inner tube be raised if it is inside the outer tube ?
Telescoping tubes always seem to have a problem with bending and corrosion. Is it possible to place the secondary extension tube external to the main mast ?
That might also make pintles, ballast weights and any external guys easier to attach.
