[RFI] Nineteen Hour Noise

[Ron, K6KYJ]

Tonight (Sunday evening 03.10.2013) I am now on Pacific Daylight Savings Time (PDST). At 1825 local, the street lights in my neighborhood did not come on as has happened in the past. My assumption is that this was a function of the change to PDST. At 1925 local, as expected, the lights did come on throughout the neighborhood.

At 1825 local, there was NO RFI noise heard at 6.990 mHz.  Nor was there any noise at 1925 local when the street lights came on.

This yields a simple preliminary conclusion: the street lights are NOT the source of my RFI noise.

Early celebration would have been inappropriate but I did start looking for DX on the low bands.  After passes through 160 and 80, I began tuning up through 40 meters. Buzz..zzzzz. The noise was back, starting at about 2025 local. Note that this is TWO hours later than the previous observed starting time.

My suspicion then narrowed to the previously discussed possibility of grow lights or some other EMI source operated by timer. (It would appear that the timer was reset by two hours.)

I hooked up a Sangean 803A portable receiver to a rooftop antenna on my SUV and dialed in 7.000 mHz and began driving around my neighborhood.  I very quickly developed some nulls in the signal and with 15 minutes I was able to localize the signal source to an area of about 100 square yards or less.  I have three suspect structures at this time, all residential (one residence has a large enclosed barn...hmmmm). I continued the grid search using a portable antenna and then switched to the Sangean's internal ferrite antenna.

My next step is to confirm the time the signal ceases in early afternoon. After that, I'll try to do some snooping without getting shot. Actually, in our part of the woods, most of the large indoor pot operations are in empty homes owned by Asian drug cartels based in the San Francisco area.

I will keep the reflector updated as I develop concrete information or obtain a resolution.  It would have been nice to have the extra two hours operating time last week when TX5K was still on!