[TowerTalk] Open wire protection devices?

[Paul Christensen]

> I was looking at the AlphaDelta units which have their gas filled devices
> built into threaded plugs. Has anyone adapted these to OWL use?
>
> Alternative solutions welcomed.

Jim,

As an alternative, I open/close the line outside the house with a pair of 
75A/10KV vacuum relays.  The relays are controlled from inside the shack.

Although there's no guarantee that lightning cannot cross the vacuum path, a 
direct strike to gas devices is also sure to cause equipment damage.  Also, 
I do not ground either side of the open-feeder line when the relays are 
open.  In essence, the antenna and the open line just float in the air, 
unconnected.  Several folks have made comments about this method in the 
past, but nobody has provided me with conclusive proof that opening a 
balanced line, then grounding  one side is superior to simply opening the 
line and letting the antenna and line float in the air.  So, unless you're 
provided with proof about this, be careful when listening to "expert 
opinions."

Best of luck.

Paul, W9AC