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Ham Radio: Some Unique Concerns

This month, Geoff, N1GY, writes about Radio Frequency Interference and what to do about it.

There are some problems that are unique to amateur radio. For instance, a week or so ago I purchased a new "High Visibility" keyboard for my computer. Wonderful, I thought, now I will be able to easily see the keys, even when operating late at night. Even the price was right.

A few days later, however, I began hearing from other hams that my signal, which is normally clear and "full quieting" had a strange hum on my transmissions. When I realized the the new keyboard was the only addition to the radio room in recent times, I swapped it out for the old keyboard. Of course, the noise went away at once. The keyboard was still working just fine for anyone else, just not for me.

A ham radio operator's needs are unique to their situation. We have a lot of high powered transmitters and receivers in close proximity to computers and other electronics and sometimes they do not play well together.

In this case, the keyboard, which has quite a bit of electronics in itself, was causing a form of interference (RFI) to the microphone lead of my radio. No radios, no interference. The keyboard that would work fine for a non ham was useless to me because it was not sufficiently shielded to keep the signal from the electronics in the keyboard from getting into the other gear in the radio room.

This is a more common problem than the general public realizes. Virtually all amateur radio gear sold these days has sufficient shielding so the the ham radio does not interfere with television, phones or other consumer electronics. Unfortunately, the reverse is not so clean. With more and more consumer devices being poorly designed and cheaply made, interference from those consumer devices is becoming a major problem for those of us in the amateur radio hobby.

What most people do not understand is that such interference is actually illegal and punishable by heavy fines from the FCC. A quick look at the label on almost any consumer device that contains electronics (such as your coffee pot, TV or nursery monitor) will show that it falls under Part 15 of the FCC rules. Those rules state that it has no protection from outside signals and that it must not cause interference to licensed equipment in other services.

The part that trips most people up is that they fail to understand just what is going on inside their consumer gear. All of them have devices that emit RFI (radio Frequency Interference) In gear that is properly constructed, shielding is in place to make sure that RFI stays inside the equipment and doesn't affect anything outside. In equipment that is poorly designed and cheaply made, that protection does not exist or is woefully inadequate. The effect can be a problem out to several hundred yards or more. An electric "invisible fence" to keep a pet inside one's property can affect radio gear up to a half a mile away if it is not shielded well enough.

Amateur radio operators have always been in the forefront of attempts to resolve these problems. They are always more than willing to assist anyone who is getting interference from amateur radio operations. Unfortunately, when the shoe is on the other foot, and the operator is getting interference from someone else's consumer appliance or cordless telephone, the same level of assistance is often not there.

Sometimes it becomes necessary for the FCC to step in and order the offender to correct the problem. Sadly, if the owner of the malfunctioning device had cooperated with the amateur operator in the first place, the role of the FCC would be totally unnecessary. In most cases, a simple filter or electronic choke is enough to solve the problem. An affected operator is usually more than happy to advise the homeowner on what inexpensive cure for the RFI is needed.

As the old chestnut reminds us all, you get more with honey than with vinegar. A little cooperation will result in good feelings all around.

This post is contributed by a community member. The views expressed in this blog are those of the author and do not necessarily reflect those of Patch Media Corporation. Everyone is welcome to submit a post to Patch. If you'd like to post a blog, go here to get started.

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