Good treadmiils use a DC motor in the 2 HP Range. If they govern the speed by driving the motor with a variable width pulse it might explain why they are so RF noisy. Given all the unshielded wiring between the controller board, the motor, and the display console it is no small wonder they radiate RF. Trying to tame the beast could be tough.
David K0LUM At 10:51 AM -0800 1/19/10, Phil Hystad wrote: >We have a treadmill and it DEFINITELY radiates noise. It produces a >20/9 signal on my Icom 706 truck when I am sitting in the driveway >and my wife is on the treadmill. As I drive away, I can still hear >the noise as it decreases in strength until about 1 mile away where >it disappears into the background noise. > >Our treadmill is NordicTrack APEX 6100. Noisy little beasts. If I >remember, they are about 20/9 peaks separated every roughly 20 KHz >across all bands. They are strongest in the 10 to 20 MHz range >though. > >You though have one advantage over your neighbor. You are licensed >to transmit RF and he isn't (I presume that he isn't licensed). > >73, phil, K7PEH > > >On Jan 19, 2010, at 10:12 AM, Bill Hammond wrote: > > > Thank you Elecraft reflector members for all of the great >suggestions on this QRN problem.. With your help I was able to >locate the problem. I would of not found it without your help. >> >> Now, I have no idea what to do about the issue, perhaps nothing. >>I now know the source. >> > > It's my neighbors treadmill. We share a power transformer >(underground utilities). Although I bet the noise is from a motor >arching and most likely is radiating at the motor as opposed to >being carried on the power line. I have hope as he is not a ultra >marathon runner and his runs rarely cause a QRT of over an hour. > > > 73, >> Bill > > AK5X ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
