[Amps] switching power supply for tube amplifier

[Alex Malyava]

Hi,

After reading discussions of "light and powerful PA for expeditions" at
Russian website (cqham.ru) I got this crazy idea of using switching power
supply in it.

What options we usually have - it is either 20-30 ponds of transformer or we
do AC rectification along with voltage multiplying. That might be good in EU
or some location with 220V, but here, in 120V-land we end up with way too
many stages of voltage doubling...
That made me thinking about switching power supply. We do have 200W PS in
our radios or next to it working just fine. So, why not to make 1000V 1A PS,
or something like that?
Assuming that the amp is for expedition, and suppose to be small and light,
I think it can be something like 500W out based on one (or two small)
tube... If making 1500-2000 plate voltage is scary we can look for
low-voltage tubes if there are any.
I am pretty sure that regardless how bright your idea is it was already
invented by somebody else, tried and buried :)
It might be long time ago and current technology gives us some powerful
switching FETs we didn't have 10 years ago...

Am I totally wrong and don't know what I am talking about?

Alex K2BB