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By Greg Lapin, N9GL
Chairman, ARRL RF Safety Committee
November 18, 2000
Radio frequency interference has been an issue between hams and their neighbors for as long as I can remember. As the expert on the subject, ARRL Lab Supervisor Ed Hare, W1RFI, can tell you, virtually all RFI problems can be solved with a little patience and some good engineering. Now, however, a new wrinkle has surfaced in this age-old problem. With the advent of the FCC RF Safety regulations, a savvy neighbor has another, less tangible weapon to use.
A friend of mine was having RFI problems with his neighbor. The neighbor was a nasty kind of guy and wasn't interested in working it out; he just wanted my friend banned from the airwaves. When my friend used his amplifier (500 W) on 10 or 20 meters, he would almost always set off the neighbor's burglar alarm (but not his own). The neighbor complained to everyone that he could. He got no satisfaction from the FCC, which realizes that most RFI is a problem with inadequate shielding or design.
The local village government told him they could do nothing and that this was the purview of the FCC. He did find a sympathetic ear in the village manager. This poorly informed bureaucrat realized that power levels were governed by the FCC, but he suggested to the neighbor that an ordinance could be passed limiting maximum antenna height to decrease the hazard.
Fortunately, this statement was quoted in the local newspaper, and the local ham population quickly mobilized to have the issue killed by the Village Board members. The neighbor even tried making a nuisance complaint to the local police--who treated it as a domestic dispute and asked both parties to play nicely and stop bothering them.
Somehow, the neighbor learned about the RF Safety regulations and tried something different. He complained to the EPA that he felt his health was at risk from my friend's radio transmissions. The EPA contacted the FCC and someone from the FCC RF Safety office in Washington, DC, called my friend and discussed the problem with him.
First they made sure that he had completed his RF Safety evaluation. They requested a copy of the completed evaluation and then had the local FCC field office arrange to make on-site measurements. They worked out a convenient time and sent a field engineer out. The FCC engineer made measurements at the property line as my friend transmitted with his amplifier on 10 meters, which represented the most likely hazard. The measurement showed less than half of the MPE at the property line.
Suddenly the police and the fire department showed up, sirens blaring and lights flashing. It seems that the alarm system had gone off, and the neighbor wasn't home to call them off. The FCC engineer talked to the local public safety officials and explained what was happening. Even though the police and fire personnel were none-too-pleased about the false alarm, they didn't direct their anger at my friend--thanks in part to an explanation from a federal official at the scene.
Someone must have called the neighbor, and he came flying home, very hot under the collar. The FCC engineer intervened and explained about the RF Safety tests that they had been performing. He asked permission to make measurements in the house. After disabling the alarm system, the neighbor led the FCC engineer into the master bedroom. My friend was instructed to transmit and there was no indication at all on the field strength meter.
Several weeks later, a letter was sent from the district director of the local FCC field office to the neighbor, with a copy to my friend. The first paragraph explained that all safety exposure requirements had been met--and even exceeded--by my friend. The subsequent two paragraphs explained that my friend was doing everything correctly, and the entire problem rested with the neighbor's equipment. He was encouraged to contact the alarm system manufacturer and get them to fix the problem.
This is a story with a happy ending. The FCC came through and protected truth over fear and innuendo. Without the protection of the FCC, hams across the country would be much more vulnerable to their neighbors' complaints. Look at it from a neighbor's point of view. Which is easier? Actually fixing an RFI problem and spending the time to educate yourself about RF safety, or getting rid of the RF source?
Many aspects of dealing with your neighbor are the same whether you are dealing with RFP, RFI, trimming trees that hang over the property line, or repainting your house chartreuse. The ARRL Technical Information Service has some excellent suggestions about how to deal with your neighbor when he or she comes over to complain about RFI. The same advice applies to RFP issues. Take a look at http://www.arrl.org/tis/info/rfigen.html#overview. Good public relations are especially important when it comes to RF Safety. There is a lot of unfounded fear out there that is hard to counteract. Consider all that is going on with cellular telephones these days. Sometimes, just being right is not enough.
My friend was lucky. There is an FCC Field Office close to his QTH. That is increasingly rare these days, and most people in the United States are not that fortunate. The FCC is not staffed to personally handle every complaint from the public. Virtually all RFI complaints are answered with a form letter. Since RFP is a newer concept, the FCC is more likely to get involved with adjudicating a complaint, but don't expect that to last very long. It is unlikely that the form letter they send to most neighbors will make them feel better. Do whatever you can to help the FCC keep us on the air.
It is the least that we can do to follow the FCC's regulations to the letter, and even beyond. Perform an RF Safety evaluation for your station, whether you are officially exempted or not. It's not hard to do and may be an educational experience for you. Learn the truth about RF Safety. Get familiar with what is dangerous about RF and what is not. Know what the mechanisms of tissue damage from RF are, and how to prevent them. With that information in hand, you will be better poised to deal with your neighbor's fears and may be able to nip potential problems in the bud.
Editor's note: Greg Lapin, N9GL, started working in the RF safety world after spending many years first studying cardiac function imaging and then brain tumor kinetics. He serves as chairman of the ARRL RF safety Committee and as a member of the IEEE Committee on Man and Radiation. A former professor of Biomedical Engineering and Neurology at Northwestern University, Lapin now works as a consulting professional engineer in the electronics industry. He was first licensed while a teenager in 1969 and continues to be fascinated by virtually all aspects of Amateur Radio. One of his many interests is electronic design, and he is the author of Chapter 8, "Analog Signal Theory and Components" in The ARRL Handbook for Radio Amateurs. His non-ham interests include making things grow in his garden and serving as commissioner of the local children's softball league. At other times--when he is not working or helping his kids with their homework--you might find him with the local emergency services agency, climbing his tower, building a new QRP rig, playing with his APRS setup, responding to QSL cards, going off on a DXpedition, or trying to get that "new one." You can reach him by email at g.lapin@ieee.org.
