"Tim Wescott" wrote in message
...
John Fields wrote:
On Fri, 27 Aug 2004 15:42:53 -0700, Tim Wescott
wrote:

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Presumably you could make a REALLY EFFICIENT setup with transistors by
operating the RF final in class E, but you get that pesky capacitance
problem back...

You are only scratching the surface. Check out the Harris DX series of high
power AM transmitters. It will blow your mind away. Basically, the
instantanous RF output power is synthesized by turning on 0 to 64 fairly low
power (~KW) modules. I don't know what the sampling frequency is, but
probably 20 KHz.. All modules are driven by a square wave signal at the
carrier frequency. There is no modulator.

Tam


* So I understand, I'm just a tube wannabe.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com