[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: High voltage leads from coax



Original poster: Ed Phillips <evp-at-pacbell-dot-net> 

A couple of things to consider:

1. Polyethylene insulation is flammable; be carereful!.  I remember
vividly seeing a movie of a big building-mounted radar system (FPS-85?)
on fire.  Had a large number of traveling wave tube amplifiers taking DC
from a giant power supply.  Somehow (no one could ever tell how) one of
the coax (must have been big stuff!) DC leads arced and caught fire,
setting the whole building full of coax on fire.  Once the outer braid
got hot enough the insulation just melted and dripped out and fed the
fire until it burned itself out.  As I recall this was at Eglin AFB and
for some reason the fire department couldn'g get to the building.  An
interesting point was that the movie accompanied a lecture on the FPS-85
(?).  When we walked into the meeting room the moving was playing along
in the background and no one paid any attention to it until the speaker
got up and pointed out what it was all about.

	Seems to me that the possibility of accidental arcing is greater in a
TC jury rig than it was in this very professional site.  While the total
quantity of inflammable material is vastly less it could still make a
nasty mess with lots of wicked sooty smoke.

2. RG58 is pretty small stuff.  Why not RG-8 (solid, not foam
dielectric) or  equivalent?

3. Even with the insulation on the wire I'd behave around it as if it
were uninsulated.

Ed