That FLIR sheet is from the 80's when the ghetto bird is hovering over your house.
Now they just use an RFI meter to look for the signature of the ballast and correlate power records to see exactly when the set up turns on and off by the spike in the power. They are using AM radios as well to find the ops by the EMI it will pick up as they near the grow op. See the equipment used is what is getting you picked off.
They have figured this out pretty much and can find all electronic ballast ops, not sure if magneto's fall in here. LED's and non-EMI/RFI equipment will require different methods.
Wanna try and see. make one of your cable TV connections loose put a ballast within 20 feet of it and watch outside over the next 2 weeks and see if a cable tech doesn't pop up talking about "Closed system ingress" or just puts a trap on your line and now PPV VOD etc won't work cause you are a one-way connection now because of the trap.
"While the FCC may not have jurisdiction in the enforcement of drug laws, an interference complaint to the FCC may result in an investigation. Grow lights can also produce a distinctive noise signature that may result in an unwelcome calling card, depending on the type of plants involved. Although marijuana may not be illegal under some state laws, it is still illegal under federal law. Should a field investigation uncover a grow light operation involving marijuana, we simply don't know what inter-agency agreements may exist between FCC and other law enforcement bodies. Many such growers might wish to cease operation of the offending device rather than risk a federal investigation of any kind.
Is It A Grow Light?
Grow lights tend to exhibit several unique and identifiable characteristics. So far, they typically produce a broadband noise, particularly across the 40m band. It propagates over much greater distances than one might expect from devices that meet the applicable FCC limits. Other clues include:
- Generally grow lights are set by a timer for 12 hours on and 12 hours off but this can vary.
- Once you have established the turn on time, listen to the noise as the lamp turns on. It’s generally noisier with less of a flat spectrum. This generally lasts about 5 minutes until the lamp is warm.
- The polarization is predominately vertical even though the lamp line may be horizontal.
- In the case of marijuana, the grow time is typically 6 to 8 weeks. At this time, the lights may be shut off for a few days while the plants are harvested and new ones made ready. "
Cites:
Personal experience with the EMI squad
http://www.edn.com/electronics-blogs/the-emc-blog/4438864/How-cops-are-finding--grow-ops--with-AM-radios
http://transition.fcc.gov/eb/AmateurActions/files/Grow_11_09_30_5275.pdf
http://www.arrl.org/grow-light-rfi
