[Amps] Ameritron Amps

[Steve Thompson]

R L Measures wrote:
> 
> On Jul 30, 2006, at 12:10 PM, Steve Thompson wrote:
> 
>>
>>
>> R L Measures wrote:
>>
>>> On Jul 30, 2006, at 8:18 AM, Tom W8JI wrote:
>>
>>
>>>> When the Chinese were making 3-500Z tubes with regular glass
>>>> and holes were sucking in the sides, Rich concluded it was a
>>>> VHF parasitic that couldn't be seen or measured. This VHF
>>>> oscillation supposedly caused dielectric heating of glass at
>>>> VHF.
>>>
>>>
>>>
>>> Correct.  Rus Healy at QST was the first who told me of this
>>> phenomenon.  However, it took Eimac a while to come up with a glass
>>> recipe that would not melt at VHF, so I was not surprised that the
>>> Chinese initially encountered the same difficulty.
>>
>> Do you know when this was? I'd like to know which date codes to avoid.
> 
> Early 1991.
Sorry, I think I didn't make myself clear. When did Eimac change their 
recipe?

Thanks,

Steve