Getting a nosiy signal to test a FIR filter

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?

Hi there,

Are your op amps able to handle the noise frequency?
Do you require any special kind of noise, or would white noise be good enough?

Just noise

MrAl said:

Hi there,

Are your op amps able to handle the noise frequency?
Do you require any special kind of noise, or would white noise be good enough?

Click to expand...

For what I need it seems they can.

I just want noise of any flavor as long it can be mixed with my clean signal.

Goo results

Good results - GOOD

My problem was one pin making no contact at all in the breadboard.

Results, here you have them. The .asc file is just a drawing for posting here.

Gracias again.

atferrari said:

Good results - GOOD

My problem was one pin making no contact at all in the breadboard.

Results, here you have them. The .asc file is just a drawing for posting here.

Gracias again.

Click to expand...

De nada

Looks good, so i guess you are all set then.