[time-nuts] Lightning arrestors for GPSDO antenna

[Dave M]

I'm looking for effective coaxial lightning arrestors for my GPSDO antennas.
I've seen several types; those completely enclosed in a one-piece metal 
enclosure (no replaceable components) and those having a replaceable gas 
discharge tube seem to predominate the list.
I'm looking closely at the gas discharge tube types, and am curious as to 
their effectiveness and durability.  I'd like to know stuff like; are they 
effective in dissipating a static charge, how do I know when the gas tube 
needs to be replaced, are the gas tubes of a special type, are replacement 
gas tube easily available, etc.

I'm interested in opinions and experiences with arrestors and 
recommendations for which type is most effective.

Thanks for comments,
Dave M