Here's a DIY article from Jeff Welton at Nautel:
http://support.nautel.com/tips-n-tricks/how-to-make-roll-your-own-carbon-ball-gaps/
The carbon spheres that Jeff mentions are made by Ross Engineering. Not sure
of the cost, but may be worth considering:
https://www.rossengineeringcorp.com/products/isolation/toroids-spheres-corona-nuts.html
Paul, W9AC
-----Original Message-----
From: Topband <topband-bounces@contesting.com> On Behalf Of GEORGE WALLNER
Sent: Monday, October 7, 2019 9:10 AM
To: Jeff Blaine <KeepWalking188@ac0c.com>; topband <topband@contesting.com>
Subject: Re: Topband: spark gap construction ideas for 160m tower
Jeff,
I use stainless steel acorn nuts on the ends of matching screws. Not a complete
ball, but the facing surfaces are rounded.
George,
AA7JV
On Sun, 6 Oct 2019 13:27:58 -0500
Jeff Blaine <KeepWalking188@ac0c.com> wrote:
> I need to add a spark gap of some sort onto my full-size 160m insulated-base
> tower. Looking for ideas.
>
> Making the spark gap is simple. What has me asking for ideas is the weather
> element - we have a lot of snow, ice, rain here and a spark gap needs to keep
> that stuff off. But put a little cover over it, right? Well, yes but if the
> cover is not fully enclosed, then you have wasps and spiders making nests
> there. If it's enclosed, then you have condensation and ants.
>
> I like the idea of W8JI's two balls close to each other - the surface area is
> large so accumulated pitting won't change the spacing and thus the BDV much.
> And the water will drain off away from the contact points. But what does a
> guy make that out of if he does not have a set of brass balls in his junkbox.
>
> 73/jeff/ac0c
> alpha-charlie-zero-charlie
> www.ac0c.com <http://www.ac0c.com>
>
>
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