I just concluded 3 days of observing the final testing of a new tetrode in the
French Thales (former Thomson) factory. I can say with first hand experience
that tubes will be around for a long time, at least at the power levels that
make sense. I'm not talking about broadcast or even communication levels, but
for industrial and scientific sources. On Monday the TH628 ran 600 kW key down.
That's with plate power of 12.2 kV Ep at 85 amps! This was up at 200 MHz. In an
amplifier smaller than the Citroen I drove this week. I'd love to know of any
other technology capable of this at comparable size, cost and efficiency. The
perfection of the art and skill of making thermionic devices is evident here.
Awesome is all I can say.
Yesterday same amp ran up to 3 MW pulsed with 26 kV at 175 amps plate current
very linearly, 66% efficient and > 14 db gain in grounded grid(s)
configuration.
It gets shipped to us in USA next week for further testing in our PA in the
southwest. There will be 2 more like this in coming months to test and install.
I'm ready to be home but have to say that time in a big tube factory dispels
any notions that I continuously hear on this forum and other places
(broadcasters and scientists) that tubes are gone, going, a dead end now. I
challenge the same pundits to come up with a superior way to generate RF power!
Sorry that this isn't directly applicable to our ham discussions here but as
amplifier builders it is more than of "academic interest", being real hardware.
73 K5PRO
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|