PaoloC wrote:
Hi,
I feel a little lazy today, and Mr. Google didn't return anything useful
to my searches.

Can anyone point me to a circuit diagram of an HF amplifier that uses a
PNP transistor instead of NPN?

I know that they behave the opposite, but unfortunately I haven't been
designing BJT amplifiers in the past years and I'm now a bit lost.

I have some spare PNP power transistors with a decent GBW (or ft), and
I'd like to see what happens if I use them as the PA stage of my
homebrew CW transmitters.

Thanks,
Paolo IK1ZYW
PNP transistors were more common in the days when germanium was
the semicoductor material of choice, with silicon NPN is the more
common type. The material used just happens to 'work better' with
one polarity than the other. Even so, there are some good HF pnp
power transistors, but as you go higher in power and frequency
they become rarer and more expensive. For QRP hf the 2N2905/7
is a good PNP output transistor (1-5w), and you can use
2-4 in pp/p.