[TowerTalk] Rain Induced Voltage

[Dennis OConnor]

This morning in Michigan we are having a mix of sleet and freezing rain... I was up early so I wandered out to the shack about 5AM to see if any Pacific DX was coming in on 80 or 160...  When I energized the antenna switch I was greeted by the sound of a frying/popping noise at about 4-5 cycles per second and an S-meter completely pinned to the right...  I know that sound quite well and instantly cut the power to the antenna switching box...  I unscrewed the coax to the one antenna that is not link coupled - meaning I have a DC connection to the actual antenna - a 160 meter dipole...  Using the tip of my pocket knife I can draw an arc between the shell and the center pin on the PL-259... The VOM reads from 5 to 7 volts DC across the connector continuous into a 1 megohm load...  There is no convective activity in the area, no thunder or lightning, and no thunder storms predicted...  The voltage appears to be induced by the rain drops dripping off the antenna wire removing
 electrons and leaving a static charge with the  ungrounded side of the antenna <coax center pin) left positively charged...
I know we have genteely discussed this before <called a scrum in some circles>, but since it is fresh in my mind, I thought I would bring it up again <also known as stirring the pot>...

denny / k8do

 
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