A friend just built a 1kw EME Amp using the freescale and he has a
whopper of a air cooled heatsink. The device is soldered directly to
the copper spreader.
Even so, he says that the top of the device branded the end of his finger
when he did an unscientific test after a lengthy transmission. He is
planning to cool the top of the device with some sort of clamped
heatsink like a cpu cooler.
I think he needs to be careful about uneven expansion and contraction
of the device.
His next heat sink is a water cooled block of copper and a small
aquarium pump.
There are several drilled passages right under the die location.
If there were no long term effects of dropping the whole circuit down
into a tank of water or 50/50 glycol, I think there would be
additional cooling benefits for the whole pc board. His Amp uses
teflon coax for matching, so the coax would need to be waterproofed,
or replaced with L and C which might be a problem on 144 and 432.
Not so much for a 160-6 meter amp, maybe.
Don W4DNR
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