I think that I have located all of the sources of RFI in my house. Some are easy to solve, others are not. Here they are:
1 There is a touch lamp in one of the bedrooms that is generating broadband noise. It is easily solved by getting rid of the lamp.
2 There is a television in the living room that is causing noise that extends from 3.4 mHz all the way up to 9.8 mHz.
3 The most vexing is the fact that I have a service called “whole house DVR” that allows us to watch recorded shows in any room of the house. It does this by using a system called “multimedia over coax,” abbreviated as MoCA. Since there are three of these cable boxes in the house, any time two of the three boxes are powered up, they begin to communicate over the house’s cable lines. This is why it was so hard to track down. I am going to have to call the tech support for the cable company and see if they can help me out with calming down this noise.

Categories: Uncategorized


SiGraybeard · June 24, 2013 at 1:10 am

Touch lamps are notorious. Sometimes they can be fixed with capacitors on the AC line, but if you can live without it – do so.

TVs are not unusual sources of RFI, especially plasma HD sets. These are harder to clean up. You might find some model-specific information with web searches, or contact the ARRL RFI help guys. ARRL RFI page. A local ham club may have an EMI expert who knows the ropes on that sort of interference.

A helpful way of thinking of RFI issues is you have a transmitter (the interferer), a receiver (you, in this case) and a path. If fix any one of the three you're done. Sometimes the answer is simply separation or reorientation. Plug the TV into a good RFI filter; not just a surge suppressor. Plugging it into a different outlet has helped sometimes.

Mark/GreyLocke · June 27, 2013 at 3:39 am

Would a choke work on the coax? I'm a Tech No Code and not to electrically inclined, but would a ferrite choke or putting 3 turns in the coax cut that down?

Comments are closed.