[Hallicrafters] antenna voltage build up and spark discharge

[Gerry Steffens]

AS recently as 1958 when I put up my first long-wire antenna with a kit
ordered from Burstein Applebee and 2 by 2 masts constructed from the Radio
Amateur's Handbook plans as I remember, the kit included a "lightning
arrestor".  The instructions that came with the kit explained that during
storms with wind, rain, snow (and maybe even dirt, I don't remember) blowing
by the antenna, a charge build up on the antenna was produced similar to
rubbing the hard rubber rod with a silk rag (do I have the right rod here?)
just like in 9th grade science.  The arrestor was no more for lightning than
a number 22 gauge ground wire.  The arrestor was in fact two conducting rods
(about 5/16 inch in diameter) with a very small gap between them.  One side
was connected to the antenna, the other to ground.  The width of the gap was
small to allow that spark to discharge at the lowest voltage possible,
through the arrestor minimizing the potential your receiver input circuit
sees, thus "protecting" it.

The porcelain "Lightning" arrestor even had the word lightning molded into
it.

Gerry


Collecting & Restoring since 1959
Gerald Steffens P.E.
Oronoco, MN


-----Original Message-----
From: hallicrafters-bounces at mailman.qth.net
[mailto:hallicrafters-bounces at mailman.qth.net] On Behalf Of edben
Sent: Monday, January 24, 2005 9:19 PM
To: Bill Gerhold; 'Philip Atchley'; 'Mark Bell';
hallicrafters at mailman.qth.net
Subject: Re: Fw: [Hallicrafters] SX-110A question (Antenna "sparking")

The old World War II Liberty Ship Radio Operator has to answer this one!

Believe me, this is no fairy tale!  Our shipboard antennas connected by a 
plug, with a long well-insulated handle.  It wasn't necessarily during an 
"electric storm", but much more likely during a "drizzle", that the antennas

would start building up a charge.  When that happened, your radio would roar

with a volume that would cover up any radio signal on the air.  I never had 
the chance to check it, but there's no doubt in my mind that at night, your 
antenna, and more likely, all the grounded "points" of the ship would be lit

up with "St Elmo's Fire," caused by such a high voltage build up that they 
are actually arcing into the air.

When this static condition occurred, one could "pull the plug" from its 
receptacle, and easily draw an eight inch or longer spark from it!  Now, if 
you doubt that a short antenna would do this, I can report, first hand, 
hearing this same "over-everything type static," when I was driving my car 
in a drizzle in central Illinois prairie country, probably about 1955.  It 
lasted for several minutes before the effect disappeared and the radio 
returned to normal.  Had I not been aware, because of my frequent shipboard 
experience with this static build up, I would never have guessed what was 
happening with my car radio and it's very short antenna.  I'm sure that if 
it had been a black-of-night, lights out, experience, one could have seen 
the glow on the tip of the car antenna.  And; incidently, I'm sure that's 
why your car antenna still has a round knob on it.  That will lessen the 
chance that this so-called "point discharge" will happen while you're trying

to hear a good program!

I have never, except for that one experience, heard that effect since my 
World War II years at sea, but be assured, it is real!

Ed Benjamin

----- Original Message ----- 
From: "Bill Gerhold" <k2wh at optonline.net>
To: "'Philip Atchley'" <beaconeer at sbcglobal.net>; "'Mark Bell'" 
<bell at blazenet.net>; <hallicrafters at mailman.qth.net>
Sent: Monday, January 24, 2005 8:49 PM
Subject: RE: Fw: [Hallicrafters] SX-110A question


> For the life of me I have never, ever seen the sparking across any
> connectors connected to any antenna I have ever had.  I know others have
> said they have seen this but I have never, even with a full size 160 meter
> dipole!  I have even put an NE-2 across a PL-259 lying free during an
> approaching lightning storm and nothing.

______________________________________________________________
Hallicrafters mailing list
Home: http://mailman.qth.net/mailman/listinfo/hallicrafters
Help: http://mailman.qth.net/mmfaq.html
Post: mailto:Hallicrafters at mailman.qth.net
----
List Administrator: Duane Fischer, W8DBF **for assistance**
dfischer at usol.com
----
Hallicrafters Collectors International: http://www.w9wze.org