[Elecraft] Shack equipment noise

["Carl, WCØV"]

What isn't mentioned is the fact that MOVs are rated by the TOTAL energy 
in Joules that they will absorb in their lifetime before they fail. The 
energy absorbed from spikes is cumulative and when the rating is 
exceeded, boom.
They are also responsible for nasty noise generated by the crowbar 
action on the spikes in making them square waves - the sum of all 
possible harmonics. I
  used to have to deal with these things when customers would use them 
in front of servoamplifiers. The noise from the square waves drove us 
crazy until we found the MOVs and removed them.

-- 
73.14159, Carl WCØV