"Richard Harrison" wrote in message
...
Richard Clark, KB7QHC wrote:
"(don`t fall for the monster under the bed stories of gazillion volts at
a bajillion amps)."

Good point! It`s akin to: "You can`t protect against a direct hit!"

Oh yeah? How about 10,000 medium-wave broadcast stations struck by
nearly every charged cloud passing overhead? Sometimes several times a
minute for a long time period. The listener is often unaware of the
instantaneous carrier drops to extinguish the arcs initiated by the
lightning strikes. And, one of the most important lightning opponents is
a large coil of large wire in each tower lighting wire at the base of
the tower. It keeps lightning as well as R-F out of the electrical
service to the station.

If tower lighting chokes stepped up the lightning, they would all be
replaced with Austin transformers or some other technique such as shunt
feed of the radio towers to eliminate the base insulator. Truth is,
lighting chokes are very effective at keeping lightning out of the power
supply.

Best regards, Richard Harrison, KB5WZI


Hi Richard, really glad to see you chime in. Even ignoring the few examples
I found that argue against the choke concept, what was more relevant to me
was that in poring over hundreds of documents lately, I can find no modern
specification for coiling the coax at any point, high or low. Not in the NEC
or NFPA, not in the descriptions and specs to nationwide antenna tower
systems, and not in National Lightning Safety Institute, University of
Florida or other acedemia writings of such protection systems. So what seems
to remain, is its record of use, perhaps prominently at one time, without
evidence that the design was ever effective. Remember that for 230 years
science seemed to support the pointed lightning rod without really testing
it against other attachment points. Now it is fairly well agreed that
blunt-tip rods were sceintifically tested to do a much better job of
attracting the leader that was headed for a given area anyway. Perhaps the
colied coax chokes are just fading away due to no real evidence that they
work, and some theory and maybe even feeble arguments that they could do
harm. From an EMI standpoint, it's hard to argue the concerns. And from
direct attachment, only a massive winding of very heavy conductor could slow
down lightning (providing there was an arc-gap for it to take as an
alternate to that slowdown). Might be why the modern lighter cabling of
todays proliferant towers find little usefulness for the concept - just as a
possibility.

Best regards,

Jack Painter
Virginia Beach VA