Ham Radio operators can assist police in catching indoor marijuana growers who are causing radio frequency interference. Operators can help by taking a radio and portable antenna into their neighborhood and using the radio to find the location of the often illegal plant being grown.
This RFI can produce many different sounds. “It can be pops, it can be a buzzing sound, whistles — just all kinds of different noises that we’ll hear,” a ham radio operator said.
Indoor marijuana “growers” only need lighting (fluorescent or LEDs), and either high pressure sodium or metal halide to produce the product. Chinese manufacturers are rapidly producing their product, thus causing large amounts of RFI between the lighting systems and nearby electronics.
Because many of the lamps and lighting systems being used do not have FCC stickers on them, compliance testing has not been done on these products, resulting in such large amounts of RFI.
Reports of interference in ham radios have been flooding into the National Association for Amateur Radio, especially areas like California and Colorado, where marijuana has been either decriminalized or legalized.
An incident took place next to the CalFire station in King City, California. RFI from the grower caused continuous humming over the fire agency’s callbox speaker and interfered with receiving radio broadcasts and calls.
While assisting with locating the, one local radio operator discovered five Marijuana grows near his house due to RFI alone.
“One industrious ham operator went to his local grow shop and borrowed several lights and ballasts to test for RFI. He found that one light and ballast set up would cause interference up to 700 meters. From our experience, we know that most indoor grows have more than one light and ballast, which would amplify the RFI,” according to researchers.
“If I can track this down, anybody can track this down. If I listen long enough, I can tell when they turn the lights off… You can tell exactly when the harvest is,” Tom Thompson, a ham radio operator, told a Colorado newspaper.
Narcotics officers use this information to their advantage to help find illegal drug operations. A narcotics offer from the San Francisco Bay Area in California has found seven indoor “grows” due to his police car radio’s interference.