[AMPS] parasitic suppressors

Ian White, G3SEK G3SEK@ifwtech.demon.co.uk
Thu, 11 Dec 1997 07:25:28 +0000


Rich Measures wrote:
>>The Big Bang will generate tremendous amounts of RF, at that instant, of
>>unknown frequencies. Zeners and the like do not handle that very well. 
>
>-   The current path from the alleged anode/grid vanishing-gas arc is not 
>through the bias zener.  However, with a parasitic oscillation, the fault 
>current path would be through the bias zener.  

Let's try to stay with detailed circuit analysis, and not fall back to
vague arguments based on "lots of RF around".

Rich is obviously correct in saying that the bias zener is not in the
path of a surge current loop that goes B+ - anode - grid - chassis - B-.
However, what happens if the grid is connected to the chassis by a choke
or resistor which then burns out? 

When the grid floats, wouldn't the electron stream then switch to the
cathode? That would blow the bias zener, unless something else such as a
fuse blows first. 


73 from Ian G3SEK          Editor, 'The VHF/UHF DX Book'
                          'In Practice' columnist for RadCom (RSGB)
                           http://www.ifwtech.demon.co.uk/g3sek

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