I am getting very strong RF interference from something on my AC Mains coming into my house. I'm in the United States just so you know. Anyway the interference is affecting the reception of ham radio equipment. I have checked out everything that could possibly cause any RF interference in my house. I actually turned off the Main Power switch and removed AC to my entire home but still receiving this interference. It's a strong signal that is strongest around 26 - 27 Mhz. Makes a loud audio buzzing sound almost like I hearing some kind of digital data signal. If I remove power to my house and bring my receiver close to the power lines outside I still receive it. I fear it is a Carrier current device or equipment that is being used by a neighbor that shares the secondary of the transformer on the pole outside. I cannot confirm this. I called the electric power company and they came and checked out things the best they could but could not locate the cause of the noise.
I'm not too familar with carrier current devices on AC lines but recently started reading about it. Does anyone know how I can detect what freqency this carrier signal it being used? I think I maybe getting harmonics from some frequency that the device is transmitting at. I can't seem to see anything on my scope 100mhz bandwidth if I look at the AC coming into my home. I guess I need to some how find out if it is really a carrier current device but not sure how to detect it and the frequency thats being used. Does anyone have any experience in this? I'm pretty sure it is not a BPL(broadband over power lines) system. That is not suppose to be available in my area.
the frequency you mentioned 27Mhz is a global band for all radio amateur and radio ham applications and using this band especially doesn't require license at all in any area in the world and called the "Citizen Band". so most wireless applications that require no license would be mainly using it like kids woki toki , old versions of wireless phones , remote control systems especially the ones used in alarm systems ,wireless intercom systems , most of today's micro controllers that is used in rf apps support up to 40Mhz embedded transceiver inside the micro , etc you name the rest.
the main thing i want tell you about is
1-you should know how much this interference harms you.
2-with witch of your appliance and instruments this signal causes bad or unwanted results
3-if it mainly in the mains i suggest you use an emi filter "electro magnetic interference" filter and it's a simple series of coils with caps connected between the live and the neutral with a special values if you search google for emi filter design you will get thousands of sites telleng how to make their calculations and how you can DIY it. DIY="Do It Yourself" .