On 06/03/2015 09:32, gareth wrote:
wrote in message
...


An AGC range of only 20dB?

You could cascade 2 of them, that would give you 23dB ;-)

Don't know to what you are replying, but one such biscuit as the RF
amplifier and a series of them in the IF chain would provide the
desired AGC range.

A good RF amplifier would make a poor IF amplifier.
A good IF amplifier would make a poor RF amplifier.

I fear that you are incorrect in your calculation, for 2 in series
with gains variable from 0 to 20 dB will give a range of 0 to 40 dB

(Think about it the other way around with resistive attenuators, and
what you get with 2 off 20dB attenuators in series)

I think Brian was taking the pi$$
(We all know these are voltage amps, so he meant 26dB :-))

In message , Jeefaw K. Effkay
writes


A good RF amplifier would make a poor IF amplifier.
A good IF amplifier would make a poor RF amplifier.

I recall once reading something like:
"Most amplifiers oscillate,
Most oscillators wont".



--
Ian