Topband: Polyphaser IS-50UX-CO vs ICE Model 303?

[Tom W8JI]

> The polyphasers are good protectors but be aware that they rely on gas 
> tubes for protection and their failure mode is one that leaves you 
> unknowingly unprotected.  After so many ionizations the gas tube will fail 
> and won't clamp on the next strike.  For a time Polyphaser made a test set 
> to verify the function of the gas tube.  We use those at work to test 
> those in use once a year and every year we find a few that have failed. 
> Polyphaser quit selling the test set (FIST4) several years back so one 
> will need to find another way to test them....maybe a meggar.
>
>

They don't only fail high. They fail low too.

One of the more common damage failures in high power amplifiers is running 
them in systems with lightning protection gas tubes that fire at lower than 
planned voltage.

That can really tear things up if the lightning protection device is the 
right distance away to reflect the wrong impedance at the amplifier output 
port.

Such devices have limited value anyway. If they let a few kilowatts of 
energy out, they will let enough back in to tear things up.