Sure, there are _op-amps_ that have cascode input stages. There are
bootstrapped cascode input stages used in feedback amplifiers that
have extremely low input capacitance and very low distortion when
driven from high source impedances. One of the FM tuner manufacturers
long ago used a cascode input stage. With transistor amps, you can
run the input transistor at low voltage and therefore low dissipation,
and have the output transistor capable of large swings, and thus get
good dynamic range. I don't know that there's any particular noise
advantage, per se. But it does let you pick the best transistor for
each part. Another variation with transistors is a "folded cascode"
where the input transistor is one polarity (e.g. NPN) and the output
one is the opposite polarity (PNP).

Cheers,
Tom

oUsama (Yuri Blanarovich) wrote in message ...
Back from good old tube days, cascoded triode RF preamps were good for high
gain, stability and low noise.

Anything out there in transistorised version, or there is there better stuff
available? Looking mainly for preamps on HF to be used with low gain antennas,
like small loops or beverages.

Yuri, K3BU.us