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Technical Topics => Equipment => Topic started by: Zoidberg on June 06, 2008, 0642 UTC

Title: Electrostatic discharge protection tips?
Post by: Zoidberg on June 06, 2008, 0642 UTC

Hot dry winds this week have been kicking up some fierce static.  I'm wondering whether to be concerned about static damage.  My Palstar R30C has what appears to be a neon ESD bulb inline with the antenna input, but I don't want to take chances.

Right now my antenna is 25' or so of magnet wire up a tree fed via a bit of TV coax.  I tested a spare TV balun, the cannister type shaped like a small tube, the usual socket on the 50 Ohm end, a pair of leads with spade lugs on the Hi-Z end.  A quick check with the meter shows no electrical continuity across the ends. I put it between the coax and magnet wire.  I'm not using this as an impedance transformer for shortwave purposes since the core probably isn't the correct type, but does it seem logical that the lack of electrical continuity between the magnet wire antenna and TV coax feedline would help protect against ESD?

Title: Re: Electrostatic discharge protection tips?
Post by: SW-J on January 02, 2009, 0242 UTC

A couple of 1/4 watt carbon film resistors anything over 1K to ground should work to 'bleed off' any charge that may develop ... tribolectic effects (sand, air rubbing, impacting your wire antenna) and even charge induction (from overhead storms) can be reduced by providing even this simple kind of resistive 'loading'.

If there is already a DC path to ground then the resistors wouldn't be necessary; I lost the front-end transistor in a piece of gear long ago where I failed to have any sort of bleed path from an over head dipole fed with twin-lead. One day, I even drews small arcs to a water pipe from this the lead in as a charged storm cloud was in the vicinity! THATS what the resistors would before on an otherwise insulated and non-DC grounded antenna.

Title: Re: Electrostatic discharge protection tips?
Post by: . on May 18, 2010, 1735 UTC

I use an Alpha Delta Transi-Trap. Very well made.. so far so good..

http://www.alphadeltacom.com/tt3g50.html

http://www.eham.net/reviews/detail/4678

Title: Re: Electrostatic discharge protection tips?
Post by: syfr on May 20, 2010, 2325 UTC

100K resistor from antenna to ground. Works great, no degredation in signal, Twenty cents....

Title: Re: Electrostatic discharge protection tips?
Post by: W7LPN on May 27, 2010, 2055 UTC

http://www.w8ji.com/lightning.htm     ;D  check this out....good reading.