I've probably posted this here before, but I once had a 160m Inverted-V at 70 feet that didn't have a DC ground. As a thunderstorm approached (but was still several miles away) I reached down to short the coax end in the shack and drew a heavy blue 2 inch long arc that traveled from the end of the coax into my left arm and out my right arm to the concrete floor. My biceps were sore for three days.
The breakdown inception voltage of 2 inches of dry air is generally considered to be over 150,000 volts.
73, Dave AB7E On 9/27/2019 1:59 PM, K8TE wrote:
For those with insulated verticals, the potential gradient is about 100 V/meter. That varies with humidity and altitude. But, you get the picture. In dry climates like here in NM, this is a big deal for commercial broadcast AM antennas. Even with the transmitter shut down, unless there is a "DC ground" on the antenna, one shorts the tower to ground first prior to climbing on or off the tower. This was a big deal when the local power company rescued three folks from our 770 tower after it "captured" their hot air balloon! Bleeding off static electricity is a big deal. Wind blowing dust, snow, or rain can generate thousands of Volts that can provide a mean shock to us humans and hurt our radio gear. I am leaving for the race track to play with my Miata this weekend. I will disconnect my antennas, just in case. 73, Bill, K8TE
______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
