>
>I once worked with a tech who spent man;y years in the employ of Eimac.
>Needless to say he had lots of tubes. This was in the days of the 250th
>and 450th. He swore that tube filament voltage should be adjusted for
>rated current rather than set to specified voltage.
An interesting idea, Dan. When new, the (more resistive) tungsten
di-carbide layer is thicker , so the filament has a bit more resistance.
By measuring decrease in filament current during recarburization, the
tube rebuilder can tell when to stop the flow of acetylene.
>
later.
>
>plantin@att.net wrote:
>
>> Hi all,
>> I just put filament voltage to my new 8169 tube for a
>> little burn in time.
>> To my surprise, the filament appears to drawing about 48
>> or 49 amps instead of the data sheet 42 amps with 9.00
>> volts at the socket.
>> Should I be concerned? Could this be the norm for a new
>> tube, then after a few hours, it will drop back to the
>> 42 amps?
>> Any informed insight would be greatly appreciated.
>> --
>> Regards,
>> Bruce W3BP
>>
>>
>> --
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>
>
>
>
>--
>FAQ on WWW: http://www.contesting.com/ampsfaq.html
>Submissions: amps@contesting.com
>Administrative requests: amps-REQUEST@contesting.com
>Problems: owner-amps@contesting.com
>Search: http://www.contesting.com/km9p/search.htm
>
>
--
FAQ on WWW: http://www.contesting.com/ampsfaq.html
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
Search: http://www.contesting.com/km9p/search.htm
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