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A Middle Ground Between Unlicensed Micropower & LPFM?

Michael Gaines contacted us after doing some research about the potential for very low power FM radio–something under 100 watts, but higher than the milliwatts permissible for unlicensed Part 15 transmissions. After an email exchange on the topic–which revealed we both worked at the same college radio station in New Jersey–I encouraged Michael to share his thoughts with Radio Survivor readers in this post. -Paul Riismandel


by Michael Gaines

Radio can be magical. Growing up in the 70s and 80s with New York radio both on AM and FM, the radio was filled with so much amazing programming: music, comedy, radio dramas, and sports. In the days of only a handful of channels on TV, radio filled in the gaps. I loved radio so much that when I got to college, I became a DJ at my college radio station WTSR at The College of New Jersey (then, Trenton State College). Being a DJ was an amazing experience, one that I’ve never been able to duplicate, even after ten years of podcasting.

After the shift to the digital realm, I found my interest in radio waned for a long time. I would listen to it every day in the car, but that was the extent of it. There’s so much entertainment on the internet that I had forgotten about radio. A few years ago, the DJ bug started to bite again and I started looking into what it would take to put together an internet radio station. After a time I wondered if it was even possible to create a low-power station in town. Radio seemed to be owned by the big corporations, but could a town have its own voice?

I started with FM simply because the audio quality is undeniably better and the band is much more popular than AM. Starting a station from scratch was close to impossible for me, but I found LPFM which is a class of service which is designed to bring radio to communities by using low power. I thought this was great for what I wanted to do, but I learned that the application window closed, and probably won’t reopen anytime soon.

If the window were to open again, I’d definitely apply, but I’d request enough power to cover a small distance – maybe a mile or two. LPFM allows stations to go up to 100 watts, but that’s more than I’d want, both in distance and responsibility at this point.

Jumping into an LPFM station may be intimidating for some people and may be too much to handle when you’re first getting started. There should be a way to serve a town without having to wait many years for the application window to open again.

My town isn’t very large, about a mile across and a mile and a half long. Optimally, I’m looking at setting something up with a 4000–4500 foot broadcast radius, but how do you do that legally? And with the LPFM application window closed, how do you do that before 10–15 years have passed?

My research brought me to the FCC’s Part 15 rules, which are designed for unlicensed, short-range transmissions. The rules are strict about how far a Part 15 FM signal can go–a maximum of 250uV measured at 3 meters from the transmitter. (Note that Part 15 rules for FM do not specify transmitter power, only signal strength as received at three meters. However, meeting this limit typically means using less than .1 watt of power. -ed.)

It’s rumored that a Part 15 FM signal can only go a few hundred feet, but I prefer testing things out myself instead of listening to rumors. (According to the FCC Part 15 permits “an effective service range of approximately 200 feet” on FM. -ed.) I bought a Whole House 3.0 FM transmitter which seemed like the best device to do my testing with. Using the transmitter in its default low-power US mode, I was able to get a decent signal between 600 and 800 feet in my car, with the transmitter sitting on the window sill on the second floor.

I’m sure it would cover more ground if I were able to raise it higher. So many factors decide how far a signal can go: obstructions, receiver sensitivity, the antenna, weather, and line of sight. Still, even if I did put the transmitter on the roof, this device wasn’t going to cover the 4500 foot radius I needed to get the signal out to the majority of my town.

Being I have a background in math and physics, I started working on numbers. Many people tell you how far Part 15 FM should go, but nobody talks about what you need to hit a certain distance. So I had to figure it out myself. Would transmitting with several times the maximum unlicensed Part 15 power limit that show that a new class of stations can be created and not cause serious disruptions to licensed stations? I found that by the numbers, it seems possible.

In Canada, their equivalent of Part 15 rules (BETS) is a maximum of 1000 uV received at 3 meters from the transmitter, and there haven’t been reports of any serious problems there. I determined that under optimal conditions, a small town like mine could be covered with a transmitter that put out a signal that measures about 1600 uV at three meters. However, that wouldn’t fit under the original design of Part 15 FM transmissions which are not intended to go far.

Asking the FCC to extend unlicensed Part 15 FM limits to either my suggested 1600 uV standard or even the Canadian 1000uV standard may work, but you don’t want the airwaves cluttered because of so many unregulated devices spewing FM signals that can go ¾ of a mile. After some thought, I decided that extending the range of Part 15 might not be solution. Instead I think it would be better to create a class which will allow a station to cover an area large enough for a small town, like a mile or two.

My idea is to have a new class which I call Community Low Power FM (CLPFM). The intent is to be between LPFM–which may be too powerful and for which new applications are not being accepted–and Part 15 FM, with coverage that is far too short to be of any use.

Since its purpose is to serve a community, the station would have to be non-profit, and have a worthy amount of local coverage. The station would have to be licensed so that the organization running the station would make sure that they don’t run too much power, don’t bleed into adjacent stations, and that they’re held accountable for their community programming. If the station were to be unlicensed, one town could see several people competing for space on the dial, and that would just get too chaotic.

Kids and adults could use the station to learn how a station works and spin records that the big stations never play, exposing more people to different forms of music easier than any internet service. It’s also a far more personal experience. Who wouldn’t love to hear their friends and family on a local radio station? It could bring a community together far better than something you’d find on the internet because you know these people personally. They’re not strangers.

I realize that in this day and age a town can run their own web site and stream their own content, but people still listen to the airwaves, and there’s a serious gap in the airwaves for the voice of a town. I think it’s time that towns get that voice on the air.

Michael Gaines runs the D20 Podcast Network.

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