[Amps] Grid fuses (was: Life and gain of 3-500Z)

[R L Measures]

On Jul 20, 2006, at 10:13 AM, Tom W8JI wrote:

>>> If the tube is not gassy, and the grid is floating, the
>>> electron
>>> stream from the cathode probably raises the grid-cathode
>>> (fil-CT)
>>> potential to a few volts negative.
>
>> I have observed this phenomenon in small receiving tubes
>> with the grid
>> floating. No doubt it applies to their big brothers as
>> well.
>
> Not quite Bill.
>
> The very reason a tube flashes over in the first place is
> the anode has a conductive path to the closest element
> inside the tube, the grid.

Now we've got a tube flashover?
> ...

R L MEASURES, AG6K. 805-386-3734
r at somis.org