[Amps] 2nd grid resistor blow Ameritron AMP 811H

[Steve Thompson]

R. Measures wrote:

>
> On Aug 15, 2005, at 2:04 PM, Steve Thompson wrote:
>
>>
>>> -   I have observed that serious parasites in 811s can put so much EMF
>>> on the filament, that it shatters into pieces and falls to the bottom
>>> of the glass envelope.
>>>
>>>
>> Even with the amp in standby?
>
>
> I was not there when it happened, I saw the 3 casualties after a Ham 
> brought the AL-811 over for a post mortem.  As I recall, he said he 
> heard a pop after concluding the power measurement, and the three 
> filaments stopped glowing.  .

The original post described resistor damage when the amp was in standby 
and with no rf applied. In that situation parasitic, or any other, 
oscillation seems highly unlikely.

Steve