Jan Panteltje wrote:
I would expect some thermistor for temp compensation, he is so proud of,
do not see it.

The temperature compensation is accomplished with a bipolar transistor
mounted to the sink near the RF devices. You can see it in the photos.
Since this transistor is also silicon, it tracks almost perfectly with
the RF devices... and with a little extra circuitry (that is voltage
regulated)... can hold the bias very stable over a wide temperature
range.

www.telstar-electronics.com