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

[Will Matney]

Bill,

I could see this if the tube was operating and the electrons were flowing between the cathode and grid then back to the cathode via ground like it supposed to. Once the fuse/resistor opens, the grid could be less some electrons. Since the cathode is still emitting electrons that are being drawn to the anode across the grid, the grid would accept enough electrons to come into equilibrium. I can't see it though taking more charge after it's equalized, and just keep charging up to some higher potential which is what I was talking about earlier in other posts. That's just not possible, or I cant see it would be. Equilibrium yes, but other no.

Best,

Will

*********** REPLY SEPARATOR  ***********

On 7/20/06 at 9:53 PM R L Measures wrote:

>On Jul 20, 2006, at 9:10 AM, Bill Turner wrote:
>
>> ORIGINAL MESSAGE:
>>
>> On Thu, 20 Jul 2006 07:16:18 -0700, you 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.
>>
>> ------------ REPLY SEPARATOR ------------
>>
>> I have observed this phenomenon in small receiving tubes with the grid
>> floating. No doubt it applies to their big brothers as well.
>>
>> My understanding is the grid accumulates electrons from either the
>> space charge surrounding the cathode or the cathode-anode electron
>> stream and has no way of getting rid of them. Thus the grid becomes
>> negatively charged to a small extent. This negative charge repels
>> additional electrons from accumulating and a balance is achieved.
>>
>> Willing to stand corrected if necessary.
>>
>
>You got it right, Bill.
>> Bill, W6WRT
>>
>
>R L MEASURES, AG6K. 805-386-3734
>r at somis.org
>
>
>
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