And don't forget ELECTRIC BLANKETS! I just found the source of a loud noise which appeared to be emanating from a neighbor's house. The noise source turned out to be an electric blanket with independent control boxes and control units (rotary controls). Each box was causing either a loud click every second or a loud AC buzzzzzz when the electric blanket's control was set to call for more heat. I took a portable Sony AM/FM/SW radio with me to the neighbor's house and walked around the inside the house with him. At the far end of the house the signal was moderately loud with the antenna collapsed while listening on 10 Meters. When we got to the master bedroom, the signal got noticeably louder. Unplugging the AC from one box stopped one of the clicks/buzzes. Unplugging the second box produced silence. In the bedroom, the noises could also be heard on broadcast band frequencies, but were not very strongly in the AM BC band outside the house.
The frequencies with the strongest signal from a noise source is often related to the length of the wires attached to it. In this case, the signals seemed to peak on higher frequencies in the 6M and 10M bands. In the case of a noisy power line, where the wires are attached to arcing hardware are physically longer, you can expect to have stronger signals on the lower frequencies. But even with power lines, in addition to using an AM BC radio, it is often helpful to use a portable radio that can tune in the 108-130 MHz AM aircraft band to find noise sources on power line poles. In your case, if you can hear the noise on a portable AM radio at the breaker panel, try killing power to one breaker at a time to see which one kills the noise. Good luck in playing noise detective! 73, Rich - K1HTV = = = From: [email protected] [mailto:[email protected]] Sent: Wednesday, January 18, 2012 22:49 PM To: [email protected] Cc: [email protected] Subject: Re: [Elecraft] Tracking down S9+ noise on 40M light dimmers touch on off lamps plasma tv sets bob k3djc On Wed, 18 Jan 2012 19:41:33 -0800 (PST) David Dietrich <[email protected]> writes: > Hi All, > > Could someone please explain the proper way to track down RF noise in > and around my house? ..... > > 73, > > David, KC9EHQ ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
