Colin has a good point- I was in someones shack (many years ago) and saw
his COAX sitting in a fruit-jar. HIs explanation was that it contained the
spark when the winter wind blew hard. He routinely disconnected his antenna
when not in use.
After I moved to the country, on relatively high ground- while in the
process of putting together a modest station, I had put up a Windom, but
had not connected it-. The PL259 was just hanging there, behind the desk.
One night, I kept hearing this 'SNAP' sound- After I had turned out the
light, I could see the source- the antenna was sparking accross the end,
every few seconds.
I got a jar, put it on the desk so I could see it, while I ran a ground
line and put a shorted 239 on the end. THe gap in a 259 , from pin to
shell, is quite large, but it was arcing regularly.- I cannot remember if
the shield was grounded ( potential from antenna to ground) or if it was
free (potential from antenna end- to end).
Interesting?
Bill- W4BSG
At 07:38 PM 03/09/2000 -0800, you wrote:
>
>Lightning has been mentioned as a possible cause of arcs - yet almost
>immediately discounted. I would like to raise the question of whether the
>dismissal should be quite so quick..
>
>I understand little about discharge from the atmosphere - but I have felt
>large enough voltage to shock me by simply touching a 30 foot wire antenna
>with no more than a dark cloud passing over.
SNIP
>Could this be one of the causes of the arcs?
>
>73, Colin K7FM
>
-
Bill Aycock --- Persimmon Hill
Woodville, Alabama, US 35776
(in the N.E. corner of the State)
W4BSG -- Grid EM64vr
baycock@HiWAAY.net
w4bsg@arrl.net
--
FAQ on WWW: http://www.contesting.com/ampsfaq.html
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|