[Amps] LDMOS PAs and high power low pass filters/diplexers

[Steve]

You can't have too much heatsink, only too little - same as with airflow 
for big valves. Even a large heatsink is useless if the thermal contact 
between it and the spreader is no good. Concentrate on flat and smooth.

Yes they are sensitive to spikes at the input, be it rf or bias. Make 
sure you know what's happening in your tx chain.

Run them at 60% output for reasonable linearity.

Steve

> I have been very fortunate and acquired a few nice 1kW class pallets
> for 6m, 2m and 70cms. They are fairly well known designs but as I
> have had absolutely no experience of these kinds of amplifiers I
> would like to do some reading. So are there any recommended papers
> application notes or books that I ought to be reading before I
> attempt to make these pallets into real world amplifiers?
>
>
> I have had a look at the Freescale and NXP websites and I have not
> seen anything that suggests suitable heatsinks beyond what is
> required for the heat spreader, this makes me very nervous. I'll
> probably end up using something far too big!