[BC] How would you build it?

[robertm]

If cost were no object then you would want a relatively large number of low power LDMOS amplifiers. First they would spread out the heat so convection cooling was feasible and they would facilitate PSM. Designing a combiner to absorb a large mismatch is not really a big deal. A modern 1 KW transmitter only has the waste heat slightly greater than a 100 watt light bulb. 

> On Jul 30, 2014, at 8:51 PM, "Ira Wilner" <bdcst at vermontel.net> wrote:
> 
> I'd start out with LDMOS devices.  And with digital RF & envelop generation
> you may very well be able to get away with convection cooling if you don't
> make the box to darn small.  I hate those wind tunnel high speed muffin fan
> transmitters required for the small surface area heat-sinks squeezed into 2