[Amps] Amp output power

Bill Turner dezrat at outlook.com
Mon Aug 24 06:21:29 EDT 2015


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On Sun, 23 Aug 2015 18:25:38 -0700, Jim wrote:

>
>The non-pulse rated 3cx800 max ratings are 2250V plate voltage, 0.6 
>plate amps. Typical operation at 2200V and 0.5A with 23W of drive will 
>get you 750W AB2 output.

REPLY:

That's interesting. At 2250 VDC and .6 amps, the DC input is only 1350
watts. At 60% efficiency, the RF output would be 810 watts and the
plate dissipation would be 540 watts. 

The tube's rated plate dissipation is 800 watts, yet in class AB with
max Vp and Ip, you come nowhere near that rating. Most tubes will put
out RF well in excess of their dissipation rating. For example, a
3-500Z with only 500 watts plate dissipation will put out 750 watts
and still be within ratings. 

The question is, why would a tube have such a high dissipation rating
if it is not capable of reaching that in normal class AB operation?
Perhaps it is intended for use in class A? 

Seems strange to me. Your thoughts?

73, Bill W6WRT


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