Yes that is what I try to do in my application, a variable gain amplifier having the gain controlled by an attack-release like circuit.
At the beginning of the post I thought I could have a potentiometer at the RF input, but you gave me an idea with the variable gain amplifier.
The class-A broadband amplifier that I am using is attached. The gain ,I think, Can be adjusted by the 3K3 anf the 750 ohm resistors.
An LDR could be added there so that the gain can be adjusted using an attack-release circuit. So the potentiometer will not be at the RF path and also the input/output impedance remains the same.
how do you think of that?
I have to say, I am anaware if by changing the value of the bias resistor the circuit falls into class-AB...