[AMPS] Filament Voltage

[Rich Measures]

>
>
>
>When measuring filament voltage at socket terminals using a digital
>multimeter, is this value corrects as per the data sheet, or must this
>reading be converted to rms, or should you use an accurate fluke type
>RMS meter.
>
Igor
Non true rms DMMs are typically quite accurate provided that one is 
measuring  sinewaves.  True-rms meters are intended for measuring the 
heating value of strange waveforms.  //  For heater type cathodes, 
accurate heater potential measurements are needed.  However, for 
thoriated-tungsten filament-type tubes, one simply adjusts the fil. V 
downward until the PEP RF output just begins to decrease -- then 
increases the fil. V a bit.  Thus, a filament voltmeter is not essential. 
  
-  later


Rich...

R. L. Measures, 805-386-3734, AG6K, www.vcnet.com/measures  


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