[Elecraft] Tracking down S9+ noise on 40M

[Bill Hammond]

My biggie was the dishwasher...documented here: http://www.flickr.com/photos/ak5x/6595335923/in/photostream
Electronic motor control seems to be the latest QRN maker, or would Plasma TV's win that award?...My noise was from DC to Daylight all bands S9.  The P3 was very handy in tracking this down.  

With a AM radio the buzz will get louder the closer you are to the offending device.  BC radios usually have some null points off the end of the ferrite BC antennas giving you some directivity.    There are some tips in the ARRL RFI 3rd edition that are helpful, as well as the AC Power Interference Handbook by Loftness, KB7KK.  These are good reference books to have. A quick glance at "The Handbook" index did not show RFI as a covered subject, but I may of missed it. 

Powering down the house is helpful but not if the offending device is on batteries :)


On Jan 18, 2012, at 9:41 PM, David Dietrich wrote:

> Hi All,
> 
> Could someone please explain the proper way to track down RF noise in and around my house?  More often than not, I always have S9+ noise on 40 Meters, making anything but really strong signals (S9+) audible above the noise.  I have only had a few instances where the noise was below S9 on 40.  I know I have to power down the house and then bring it up one circuit at a time with my radio on battery power.  I also know I am supposed to use a handheld AM radio to listen as I walk around the house.  I don't know what I should be listening for, or where to tune on AM to hear what I am supposed to hear.  Now that I am getting back into operating more regularly, I would really like to see where some of this noise is coming from; and reduce or eliminate it if at all possible even if it means shutting something off while I am on the air.
> 
> 73,
> 
> David, KC9EHQ
> K1-4 s/n 2051
> K2/10 s/n 7164
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft at mailman.qth.net
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html

Bill Hammond
wham727 at aol.com
Bill Hammond-AK5X
ak5x at mac.com
ak5x at sbcglobal.net
K3 #69
P3 #817
KPA500 # 149
K2/100 #4637
K1 #2033
KX1 #1023
T1