The Conejo Valley Amateur Radio Club is a not-for-profit international organization of amateur radio enthusiasts. We provide education forums, publications and peer interaction opportunities that enhance the knowledge, skill and professional growth of our members.
Andy Ludlum – K6AGL
Roger Johnson is a retired Coast Guard officer in Maine. He was afraid his HF radio had turned into a boat anchor. Every time he turned it on, he’d hear harsh, grating static, like something generated by a lightning strike, except it never stopped.
Johnson drove up and down the streets of his neighborhood with a spectrum analyzer hooked up to his laptop, determined to locate the source of the buzz.
He found it less than a mile away at the home of a licensed marijuana grower. Cultivation of recreational marijuana is now legal in Maine, along with Colorado, Massachusetts, Oregon, Alaska, Washington, the District of Columbia and of course, here in California.
The problem comes from the electrical ballasts regulating the indoor lamps used to grow pot. Grow lamps are distinctive because they power on and off for 12 hours at a time. According to the ARRL, they can be powerful enough to produce the same amount of radio interference as a 1,000-watt AM radio station. Some of these cheap ballasts have phony FCC-compliance stickers. One inexpensive ballast sold by big-box retailers produced 640 times the level of interference of a legal unit.
In fact, even if none of your neighbors are growing pot, it’s unlikely you can find anyone on your block who is not radiating RF and adding to the noise floor.
But what our neighbors do is only part of the problem. It’s too easy for hams to unknowingly create noise sources in their own homes. Many people have converted recessed lighting (pot-lights of another kind!) from incandescent lamps to LED types, which radiate RF. You might have a couple dozen recessed LED lamps in your house, not to mention security lights and even night-lights. To convert from household power to low voltage, LED lamps use noisy, built-in, switching power supplies. It’s not just LED lamps. Many people are adding “smart” digital thermostats, stoves and washing machines. And that is by no means a comprehensive list.
Individual problems, such as the non-compliant ballasts, have been solved by employing a filtering device that almost eliminates the static. But, the ARRL wants the FCC to take a stronger stand against devices that give off more interference than federal law allows in homes. There are hopes President Donald Trump's new FCC chairman, Ajit Varadaraj Pai will be sympathetic to hams. He has praised pending federal legislation aimed at helping amateur radio operators with their special problems.
The switch to energy efficient, but noisy, digital appliances appears to be happening at a pace our regulators just can’t keep up with. Amateur radio operators need to be educated in order to become focused and effective lobbyists. Otherwise, one day you’ll turn on your radio and hear nothing but static.
We’re going to spend time this month discussing the problem of the rising noise floor. This month’s guest speaker, Richard Rudman-W6TIA, will explain noise from a broadcast engineer’s perspective.