I plan to carry a basic test of a FIR filter using an already available 400 Hz sinusoidal signal, contaminated with noise on purpose.
Had some success to generate noise with the base-emitter diode of a BC338 polarized as a zener.
My questions:
a) What should be the simplest way to amplify the noise with an opamp? AC amplifier? I am trying to use several CA3140 (single supply opamp).
b) To add noise to the signal, I tried to implement a summing amplifier but up to now all I get is the original signal quite clean. Or it is how it looks. (?)
c) Am I too off track here?