[Elecraft] KPA500 Faulting on high SWR on power rise

[Don Wilhelm]

While all the "facts" about the voltage ratings of the gas discharge 
protectors are correct - that is only true if those devices are new and 
have not 'squashed' a number of events.

Please consider that this ham's problem with the Alpha-Delta protector 
may be simply that the gas-discharge device in the protector has 
absorbed enough energy (both from lightning and from RF) that its rating 
is no longer the same as a new one.

Those devices do degrade after a number of "events"-
That is the reason why Alpha-Delta gas discharge devices are replaceable 
- they do not last forever.  Some other protection devices do not have 
parts that are as easily replaceable, and you have to replace the entire 
protector.

73,
Don W3FPR

On 2/25/2018 6:42 PM, john at kk9a.com wrote:
> Your 5KW example is RMS voltage and peak would be 707v. I am not sure how
> much moderate SWR effect this value but clearly the 1000v Alpha Delta
> discharge tube should be adequate for an Elecraft KPA-500 unless the SWR is
> horrible.