Lightning at antenna farm

[TomZ]

Downward Positive Cloud-to-Ground Lightning Flash Triggers Upward Positive Leaders from Towers
by ZT Research PLUS 4 days 22 hours ago
A positive cloud-to-ground lightning flash triggers upward positive lightning leaders to form from three television towers in Rapid City, South Dakota. Filmed at 9,000 images per second, the video shows positive leaders descending from the thunderstorm with one connecting to ground. The resulting return stroke creates a fast electric field change which causes three tall television towers to initiate upward positive lightning leaders. Fast, short duration, bidirectional/bipolar recoil leaders form on positive leader branches that become cutoff from their main channel.

http://vimeo.com/45803576

 

[TomT]

Why you need good grounding at FM towers. Preferably something that resembles an AM system.

Those upward feeders need to pull electrons from somewhere, best if it is not through transmitters and other pricey equipment.

 

[BobOnTheJob]

Why you need good grounding at FM towers. Preferably something that resembles an AM system.

Those upward feeders need to pull electrons from somewhere, best if it is not through transmitters and other pricey equipment.

And that ground system needs to be bonded to the AC Power Panel ground...something very often overlooked. The difference in potential between the tower ground and the AC ground is sufficient to turn the equipment between the tower and the AC ground into a very expensive fuse. Very cheap to do, very expensive to recover from not doing.

 

[TomT]

Excellent point. Often the only ground for the incoming AC is a ground rod--which may not be all that deep if there's rock just a few feet down (common here in WV on the hill tops).

 

[chriscollins]

Thank you for posting that video. Amazing to see something like this.