> > ... work, but thousands are in use. I have always added
>> Rich's grid fuse resistor scheme when repairing SB-1000's.
>> No tube failures to date that I know of.
>You'd be far better off to use a HV glitch resistor, and leave the grid
// Tom professed that using a directly-grounded grid increases the grid
resonant frequency, and therefore increases VHF stability. I checked
this out with a dipmeter. There is virtually no difference in res, freq.
Also, our retrofit kits include a glitch resistor.
>Resistors in grid leads are bad news unless there is
>good reason to add them,
// Such as one does not have a free supply of new tubes,
> because they let the grid rise to anode
>voltage if there is a fault.
// Does this make sence? The breakdown potential in a 3-500Z is
>If the grid rises to anode voltage, the grid naturally no longer
>shields the filament from the HV surge. That means the filament is
>many times more likely to rise to B+ rail.
// This statement causeth me to rail.
>Better to simply put a proper surge resistor in the HV lead, and let
>the arc pull the anode low through a series resistance!!!
- R. L. Measures, 805.386.3734,AG6K, www.vcnet.com/measures.
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