Jim Barber N7CXI wrote:
> This discussion of "super semis" makes me wonder if anyone is still
> engaged in vacuum tube research these days. Could any of the basic tube
> wear points be improved on with modern technology? Could filaments be
> made to emit twice as long without degradation?
I think only emissive materials that are more efficient at lower
temperatures remain to be
exhausted on this area.
> I just looked at the CPI Eimac site and I can't see where they're
> motivated or have the resources to innovate at the basic level. They
> list "Amateur Service" as a product category, which can't bode well for
> volume sales... Assuming MOSFET technology passes tubes by at high power
> levels, will they just go quietly into the night?
> I hope not - there's no second chances with current solid state devices.
> Generally speaking, they do not degrade gracefully... ;-)
I do not think developing 30 kW of RF across 6 MHz (ATSC) can be developed
with 30, 1.0 kW
devices anywhere as cheaply or efficiently as one IOT tube.
When you combine a bank of semiconductors with an bank of semiconductors and
combine those with
another gaggle of amplifiers the combining losses (from each amplifier having
different gain)
eventually eats up so much power, you loose too much efficiency to compete with
one huge device.
--
Ron KA4INM - I've been carving my initials on trees and furniture all my
life
'course I didn't use my own initials, I'm not stupid ... Earl
Pitts 4-2-9
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