On Sun, 29 Aug 2004 02:44:25 -0500, "Tim Williams" wrote:
"Gary Coffman" wrote in message
.. .
Back in the day, the 4-125A worked at 200 MHz when transistors
were straining to do milliwatts at 1 MHz. Of course that's all changed
now. About the only place for tubes today is when you *have* to
deal with very high voltages. Otherwise, transistors are preferred.

They still find a niche in FM and TV transmitters, although I don't know
what kind of proportions are used right now. Also still popular with HAMs.

There hasn't been a new FM or VHF TV transmitter built using tubes in
the last 10 years. Those markets are all solid state today.

UHF TV transmitters mainly still use depressed collector klystrons or
klystrodes, though transistors are starting to invade that market too.

Hams do use tube amps, though more and more are switching to solid
state amps.

Certainly, with the transformer I have, I need tubes... unless someone can
dig up a 2.5kV FET.

Yep.

Gary