----- Original Message -----
From: <wc6w@juno.com>
>
> Some further details are shown in the Proceedings of the IRE, Vol.
> 44, December 1956, pp 1706-1712. The curious may wish to recalculate
> the numbers in Appendix One with a 90% efficient RF power stage, in
> lieu the 80%, plus a 90% efficient Class D audio modulator instead of
> the (55% efficient) 1950's vintage Class B stage.
>
> An article describing a 90% efficient RF stage is posted on my
> webpage at:
>
> http://wc6w.50webs.com/wc6wamps/index.html?fr422.html
>
> Soooo...now, how much power does the plate have to dissipate, running
> 2KW peak, if it's 90% efficient? Don't forget that the average power
> of a (two-tone) SSB signal is only half the peak. The tube won't even
> glow.
>
>
There is an intersting article in QEX this month where the
author describes a 2KW PEP 80/40 meter output amplifier
using 4 TV sweeps tubes with a switchmode power supply
providing envelope restoration. Claimed 3rd IMD at 2KW
PEP is 35 dB below a single tone at 83% efficiency. Weight
(including power supply) is only 8 kilograms.
73, Mike W4EF................................
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