On 05/03/2015 16:04, gareth wrote:

eg, an RF amplifier, 50 ohm in and out, 12V supply, agc input
to give a gain range from unity to 20dB, to be used as RF or IF
amplifiers.

An AGC range of only 20dB?

Now, it is possible that with the onset of SDR, that such an
approach would be obselescent

There's nothing wrong with that (apart from your spelling). This is
amateur radio; it doesn't need to be state of the art, as long as does
the job.

but SDR itself is already notorious

Where is it notorious?

for being an off-the-shelf Cheque Book (CB) approach both for
the hardware and also the software.