[Amps] Amp output power

[Steve Thompson]

If you check at
http://www.g8wrb.org/triodes/

there's several data sheets. I came across a copy of the one with 
1370W output spec. and copied it to David to host. I believe there 
was a spell where FCC applied rules relating to output power spec. 
of the devices in a transmitter, hence the 750W rating appearing 
so a pair was valid for a 1500W amplifier.

I think the same applied in the case of Svetlana 4CX800A data.

Steve

> ------------ ORIGINAL MESSAGE ------------(may be snipped)
>
> 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