Just make a small untuned or tuned loop if it is band specific. You can find details herehttp://www.w0qe.com/RF_Interference/tracking_down_rf_interference.html
I used small EMC loops. I have both professional and homebrew versions that work well. I like the small sniffer loops because you can pinpoint the exact spot of the RFI.
You really need to go around your own house first with a sniffer loop.http://www.millertechinc.com/pdf_files/MTI%20TN101%20Simplest%20EMC%20Magnetic%20Field%20Probe.htm
I small 2 or 3 inch homebrew loop is the most useful size for nailing the interference source.
A SDR radio can be an invaluable tool as a RFI spectrum analyzer. I use one with my lap top and small loops. I can find most RFI within in 30 minutes.
Most noise comes from those nasty wall warts and other switch mode power supplies. Anything that has LED's in them like LED lights that are made in Chine will cause problems. All the Chinese manufacturers
have fraudulent certification markings on their products. They being dumped all around the world and our governments are doing nothing about them. 99% of the EMC problems is from cheap Chinese junk
manufactured in China. The unfortunate thing is that big name companies like HP, Cisco, Nokia and even Apple are being fooled by these Chinese EMC fraudsters. When you have companies that will poison their own babies, EMC
fraud would not even register on the chinese manufacturers conscience!
I'm looking for solutions for identifying this RFI on 80 meters. I have link below to look at it. I did all the basic steps including opening the house main breaker, using my portable rig in my car- tuned to one of these harmonics. It is quite loud around my next door neighbor's house.
It is 24/7 constant, no rotational or intermittant nature. It smells like a switching supply, and is loud. It is around 5khz wide and spaced 50khz.
Can someone suggest a simple directional antenna for 80 meters that I could build that would be managable? I would like to try and pinpoint this-
It may be coming from our outside utility distribution, which is underground. I have allready asked my neighbor if he might give me a hand, offering to repair or replace whatever it is. No luck there yet...
Anyhow- much appreciate any info, I guess this is the price of living in the city.