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-boun...@contesting.com> On Behalf Of GEORGE WALLNER Sent: Monday, October 7, 2019 9:10 AM To: Jeff Blaine <keepwalking...@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 <keepwalking...@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> > > > _________________ > Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _________________ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _________________ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector