Getting a nosiy signal to test a FIR filter

Thread Starter

atferrari

Joined Jan 6, 2004
4,764
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?
 

Thread Starter

atferrari

Joined Jan 6, 2004
4,764
You may be off to a rough start. A CA3140 is a dual supply only op amp.

There are methods of generating noise - http://sound.westhost.com/project11.htm

http://www.coolcircuit.com/circuit/pink_noise_generator/index.html
It can be used (did it yesterday) with single supply. (+ input to Vdd/2).

I was aware of both links.

Years ago I bought one MM5837 but couldn't find it so had to resort to an NPN transistor.

My problem is what comes AFTER that, thus my questions.

Gracias for replying.
 
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