Topband: Covered /bare antennn wire

[Gary Smith]

I used to have an ICE model 303 lightning protector which I believe 
was a gas discharge tube with a toroidal choke in parallel to ground. 

I recall the toroidal choke was to continually bleed the electrons 
from the antenna so there would not be a buildup sufficient to cause 
damage and to not create a focus for a lightning strike. I may still 
have it in one of my boxes of Ham Gear still back in the midwest.

I also remember my father running a not too terribly long wire 
outside with a Rf ammeter in series indoors & watching the movement 
increase as a storm approached.

Gary
KA1J

> 
> On 2012-11-15, at 3:42 PM, Bruce wrote:
> 
> > Dry blowing snow or high wind can cause quite some voltage build up
> > on a antenna, especially a long one. It is possible to draw quite an
> > arc to ground. There have been reports of high voltage
> > electrocutions from antenna static build up in Short Wave Broadcast
> > stations. A short stick was mandatory for maintenance periods. And
> > yes, I did work at a shortwave station with 500 KW transmitter
> > output.
> > 
> > So receiving antenna wire insulation could have some benefit if the
> > voltage on a bare wire is leaking to a tree limb or across an
> > insulator. Beyond some point all insulators can fail.
> > 
> > Indoor antennas do hear static, but I have never seen any evidence
> > of voltage build up. ( The building may provide adequate
> > insulation.)  
> > 
> > 
> > Out of curiosity, has anyone ever really done testing of voltage
> > buildup on a insulated antenna wire, VS a non-insulated wire ?
> > Indoor antennas VS outdoor antennas of equal size?
> > 
> 
> 
> Hi Bruce,
> 
> I am not so sure that the notion of insulated vs. uninsulated wire
> holds true in long wire spans...
> 
> Case in point: years ago when I first erected my 1500' long Beverage
> antenna here, I was specific in using insulated wire though its entire
> course because it runs through a grove of trees at one point. Well,
> one day, in the advance of an approaching storm front, I decided to
> ground the end of the Beverage in my shack. I could feel a "tingling"
> sensation as I man-handled the wire, negotiating my way to the common
> ground pipe that I have running the length of the back of my operating
> table...imagine my complete & utter shock as I neared the wire to this
> same pipe, and managed to induce 1/8" long blue arcs from the pipe to
> the wire!
> 
> Since that time---FWIW---I have always had a rugged 2.5 mh. RF choke
> clipped between the wire's end where it attaches to the matching
> transformer, and ground. In theory this acts as a static drain, I
> guess, but does not induce signals to ground. I've heard that a
> multi-megohm resistor will do the same thing at this point...
> 
> ~73~ de Eddy VE3CUI - VE3XZ
> 
> _______________________________________________
> Topband reflector - topband at contesting.com
>