Re: 20 joules at 100 bps vs 4 joules at 500 bps

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Ed Phillips <evp@xxxxxxxxxxx>

"That's observed field at the ground before a lightning strike
(typical numbers are in the few kV/meter, but sometimes as high as
20kV/m).  Calculations of the overall field (i.e. the voltage
difference between cloud and ground divided by the height of the
cloud) can actually give lower numbers. (B&R say hundreds of V/m)"

	I had a demonstration once of field strength without a lightning
strike.  Had a two-meter ground plane antenna on the roof of the house,
maybe 30 feet above the ground.  During CB weather I always grounded all
long-wire antennas and disconnected the BNC coax connector from the
radio and tied it to a steam radiator for ground.  I came home one day
when there were very dark clouds passing low overhead and heard a
snapping sound which turned out to be pretty regular (one every second
or so) sparks jumping across the BNC plug.  Probably at least 1/16" long
and maybe more.  The voltage was developed between the ground plane to
which the outside of the cable was connected and the 18" high center
radiator rod.  No lightning associated with that particular cloud.
Don't know what the breakdown voltage was but it was probably at least a
few hundred volts.  Must have been over 1 kV/meter field.

Ed