[TowerTalk] DO *NOT* WORK ON ANTENNAS During Rain

[Jim Jarvis]

Dear TT:

The voltage gradient in a broadcast antenna ground field,
in the event of a direct strike has been modelled, and
confirmed by measurement as 1,000v/m.  This was reported
in BroadcastEngineering, as long ago as 1970.

My instructions to engineering staff in event of a squall
while within the antenna field was to HOP, or maybe to run,
making certain that two feet never hit the ground at the same time.
They all laughed.

We had opportunity to test it.  The one guy who DID allow two feet
to hit the ground simultaneously was 190' out, at the edge of the
radial field, from a 190' tower.  He was treated for third degree
burns in both feet, which were maybe .7 meter apart.

Another time, while in college, I worked in local TV, and used to observe
lightning
hit a water tower, 1/4 mile from the studio building.  Hearing arcs on our
CB antenna feeder, I put a DVM across the coax.  1200V spikes were
recorded on an analog meter, coincident with each strike.  The one turn
transformer
effect should not be underestimated.  If you're the secondary, it could be
shocking.

Jim/N2EA