John K. Browne wrote: Thanks for the inquiry. It depends on the make-up of the "noise". These filters are mainly for Radio Frequency noise but they work over a very wide frequency range and have solved problems similar to yours in the past. Of course there is no guarantee that it will solve your noise problem.
Sincerely, John K. Browne

After reading your page about line noise, I started looking at the way I had everything hooked up:
I have 3 phone outlets, one of them was hooked up but not in use, I unplugged that one. Another one had a caller I.D. box, an answering machine and a cordless Sony phone hooked up to it. All of the wires including the power supply's extension cord, phone line..etc. were all shoved together in a big pile behind the couch! So I separated all the wires real good so that the power lines would'nt be next to the phone lines and also replaced a couple thin insulated phone lines with some thicker ones. I then checked my line noise and it's one hell of allot clearer! I also checked the line running to the computer and it already has some kind of small filter on it? But thanks for your response and willingness to work with me on it! It's not everyday that you can find someone who will give their time to help for free.! If I still have problems I'll e-mail you for the filter. Thanks, Rod

Thanks again for your letter. I finally got an RF engineer to look at the problem and after tightening some wires at the point of entry into my house, the RFI virtually disappeared! He thinks a loose connection was causing the signal to be rectified, (at least I think that is what he said.) Anyway, the problem is fixed and I can go back to work. I'll keep the information you sent me for future reference, in case other problems arise with new equipment that I purchase. The AM tower is still very close. Thanks again.
Best regards, Ed
Click on the picture for RFI filter construction.

RFI Related Links:
American Radio Relay League RFI
Ground Loop Problems
More RFI Links!