If memory serves me right there is a ICM band between 10 and 11 meters that would be a logical place for an welder. Assuming they are using a power oscillator the signal could be quite broad band and unstable just like a microwave oven. It also sounds like a foreign design. I think a call to the FCC is in order.
Fred, AE6QL -----Original Message----- >From: Dan Maase AC6DM via Elecraft <[email protected]> >Sent: Oct 14, 2014 8:06 PM >To: [email protected] >Subject: Re: [Elecraft] HF noise.....10 M > >These "weeblies" are all over the 10 meter band here in northern Calif >Monday through Saturday; gone on Sunday. Best I can find is that they are >radiated emissions from HF ultrasonic welders (used to seal plastic >packaging, emboss car mats, etc.) They sound like they are a high power >oscillator which changes frequency during the welding operation; starting >high and decreasing in frequency as the weld is accomplished. Such welders >are not supposed to operate in the ten meter band in the US, so I suspect >they are "rogue", operating international. >Dan >AC6DM > > >Anyone have any idea what those "weeblies" are on ten meters? They >typically start high in frequency and flitter past the receiver then stop >abruptly. They sound like a very unstable oscillator, > > > >-- >View this message in context: >http://elecraft.365791.n2.nabble.com/HF-noise-30m-tp7593789p7593884.html >Sent from the Elecraft mailing list archive at Nabble.com. >______________________________________________________________ >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 >Message delivered to [email protected] ______________________________________________________________ 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 Message delivered to [email protected]
