Filter design advice

Hi all,
I made a voice transmitter and receiver with 900MHZ linx modules, and it works great accept for the hisssss that overpowers small noises. I'm just using a regular ol' LM386 as my amplifier.

I want to make a 3khz low-pass filter. I just need some advice on what kind of filter would be the best? active, passive? LC, RC? I simply don't know where to begin with this :?

A simple R-C filter should be all you need. Try 10K and 4.7nF If that is not enuf attenuation of the Hiss, put another section in cascade.

Zach,
If that is not adequate, send me a PM and I'll design a simple LC filter for you.

All you need is one L and two C for a n=3 Butterworth filter.

Or, two L and 3 C for a n=5 (steeper slope)