Lo,
Pneumatic masts are also quite popular with the military, so it might be
worth checking surplus stores and similar sources. Most are designed only to
take a small UHF array, a couple of lamps or a wire dipole. Most types use
key collars to lock each section in place (so you can disconnect or switch
off the compressor while the mast is up).
GTE produce a 115VAC hydraulic "Magic Mast" for the US Army. Radiation
Systems Inc. in Sterling, Va., is one of the USAF's major suppliers.
Hilomast is probably the biggest supplier of civilian pneumatic masts in the
US. Their URL is:
http://www.aoa-gps.com/hilomast.htm
Clark Mast Teksam at Binstead IoW has the largest range of telescopic
tubular masts in Europe. Racal is another major supplier to the military.
Just as broadcasters tend to buy a "turnkey" OB/ENG truck fitted out to
their spec with the mast included, so the military buy their masts as part
of a specific antenna system (I think the Magic Masts go with the Patriot
anti-aircraft/bird-scarer system) so they tend to arrive surplus when a
system is being decommissioned.
73
Al, GM4BAP
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