Amps
[Top] [All Lists]

[AMPS] Filament current

To: <amps@contesting.com>
Subject: [AMPS] Filament current
From: 2@vc.net (measures)
Date: Mon, 21 Feb 2000 23:28:24 -0700
>
>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? tungCould this be the norm for a new 
>tube, then after a few hours, it will drop back to the 
>42 amps?

The opposite is the case.  As a tube ages, the tungsten carbide layer is 
slowly replaced by (less-resistive) pure tungsten and fil. R decreases 
slowly - thereby causing filament current to slowly increase.  .    If 
you are sure that this tube has low hours, perhaps the filament is 
somewhat atypical.  

cheers, Bruce

--
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


<Prev in Thread] Current Thread [Next in Thread>