[AMPS] 3-500Z Grid Current Rating

[Rich Measures]

>
>I have a single 3-500Z amplifier. When I run it at 2.4kV EHT at the rated 
>400mA of anode current, I get 450W out with 130mA grid current and 60W drive. 
This
>is on 50MHZ. The problem with this is the low efficiency and subsequent 570W
>anode dissipation.
>
>I can make the amplifier more efficient my letting the grid current 
>increase - I have
>a low EHT after all, but at 175mA Grid current and 350mA anode current I 
>get the same
>power out - 50% efficient and within ratings at 450W anode dissipation.
>
>How can I calculate the grid dissipation ? Is 175mA Ig really too much?

A close enough method:  Measure peak cathode potential with an 
oscilloscope and probe.  (typ value is 115v) Calculate the RMS value by 
multiplying by 0.707.  Multiply by the indicated grid current.  .//  
175mA is well within the 20w rating.  
>
>.....
-  cheers, Mike
>
>
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Rich...

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


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