[TowerTalk] Polyphaser failure mode (Rick Stealey)

[James Wolf]

The failure mode of a gas discharge tube (GDT) is a short.  If it fires
during a strike, it will momentarily shunt to ground and either recover or
cause a permanent short.  This momentary firing of the tube in some cases
can cause build up on the porcelain which in turn can cause intermod in both
transmit and receive.

Jim - KR9U

>All that's inside a polyphaser is a series capacitor and a gas tube to
ground.
>At least for incidental (whatever they're called) strikes, doesn't the gas
tube just conduct for a few microseconds and go back to life as normal?  And
able to do this thousands of times?
>If Pete had a larger strike, and the element sustained more damage I'd be
very interested in knowing what happened inside the little box to leave it
in a shorted or a low resistance mode.

>A few years ago I made my own.  A bunch of SO239s on a panel with gas tubes
to ground (about $2 each) and a series cap, or 2 or 3 on the 160 meter
antenna.  So far so good.

>Rick  K2XT