[Amps] Need Svetlana 3CX2500F3 Info

[R.Measures]

>Building up a RF deck around a hamfest purchased  Svetlana 3CX2500F3
>tube. Would like to determine which one  of the  factory bonded  HD
>filament cables is  internally attached to the cathode. 

**  Hello, Ron - - Both are the cathode since it is a directly-heated 
filament-type electron tube -- i.e., thoriated tungsten filament/cathode. 
 Is the ... F3 going to used as a linear amplifier?.  

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