{"id":49367,"date":"2020-09-21T23:21:31","date_gmt":"2020-09-22T06:21:31","guid":{"rendered":"https:\/\/www.radiosurvivor.com\/?p=49367"},"modified":"2020-11-28T13:58:23","modified_gmt":"2020-11-28T21:58:23","slug":"social-distancing-sparks-interest-in-part-15-unlicensed-broadcasting-but-caveat-emptor","status":"publish","type":"post","link":"https:\/\/www.radiosurvivor.com\/2020\/09\/social-distancing-sparks-interest-in-part-15-unlicensed-broadcasting-but-caveat-emptor\/","title":{"rendered":"Social Distancing Sparks Interest in Part 15 Unlicensed Broadcasting, but Caveat Emptor"},"content":{"rendered":"\n


It seems that social distancing has made unlicensed Part 15 radio a bit more popular. \u201cPart 15\u201d refers to the part of the US broadcast regulations that cover unintended transmissions and radio frequency interference. Essentially, this means tiny radio signals whose transmission can\u2019t be avoided or are negligible. It also covers tiny radio transmitters, like the kind that fit into your cars 12-volt socket to broadcast your smartphone into your dashboard FM receiver, or, less commonly, AM transmitters used by real estate agents to create \u201ctalking houses\u201d for drivers by. <\/p>\n\n\n\n

With restrictions and good sense preventing many churches from holding in-person services, many apparently have looked to Part 15 broadcasting to transmit sermons to parishioners parked in their car. With a broadcast range of several hundred feet on the AM dial, it\u2019s a way to bring people together for a shared experience while keeping them safely apart. All without requiring attendees to have smartphones or use up their mobile bandwidth (assuming a church is somewhere with reliable wireless coverage).<\/p>\n\n\n\n

While a variety of Part 15 AM transmitters have been on the market for years, a new system actually calling itself \u201cParking Lot Radio<\/a>\u201d is in development right now. Suggesting uses for the system, the project\u2019s website says,<\/p>\n\n\n\n

In the current climate of Covid\u201319, the Parking Lot Radio allows churches to hold \u201cdrive-in\u201d services. Other organizations can hold lectures, film screenings and other events, while maintaining social distancing.<\/p><\/blockquote>\n\n\n\n

While a few hundred feet or broadcast range is probably sufficient for a large percentage of worship houses, I can imagine it\u2019s still not enough for some larger mega-churches, which might want to reach hundreds of cars in acres of parking lots.<\/p>\n\n\n\n

It\u2019s possible this limitation is behind a letter from Tennessee Rep. Mark Green, who wrote to FCC Chairman Ajit Pai asking for temporary waivers<\/a> be issued to houses of worship for \u201clong-range FM transmitters.\u201d He specifically asked for the ability to \u201coperate FM transmitters with an effective range greater than 200 feet.\u201d<\/p>\n\n\n\n

Careful with that FM Transmitter, Pastor<\/h3>\n\n\n\n

It\u2019s notable that Rep. Green\u2019s request was for FM transmitters, which are far more limited under Part 15. While the regulations for the AM dial put significant limits on transmitter power and antenna length, there\u2019s no explicit limit on the signal distance. Clever and careful engineering can wring out a little more reach, and distances closer to a half-mile or more can be achieved.<\/p>\n\n\n\n

But the FM band is regulated by a tight signal strength limit (250 uV\/m) at 3 meters from the antenna, causing one engineer writing in Radio World<\/a> to summarize the situation as, \u201c[b]asically if you can hear them more than 250\u2013300 feet from the site they\u2019re not legal.\u201d<\/p>\n\n\n\n

Yet, a simple search for \u201cFM Transmitter\u201d on Amazon quickly turns up a product advertised as \u201cTransmitter for Church, Dual Mode Long Range Stereo Broadcast with Antenna,\u201d that promises, \u201c[t]ransmission distance more than 300 meters (In the line of sight, field, open land).\u201d It even promises, \u201cFCC certified,\u201d leading the average shopper to think they\u2019d be ready to broadcast legally more than 900 feet away.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

Don\u2019t hit that \u201cBuy Now\u201d button yet. <\/p>\n\n\n\n

Digging deeper into the product description we see the transmitter clearly listed as delivering \u201c0.5W\u201d which very like means a half-watt of power. Though it doesn\u2019t sound like much compared to even LPFM\u2019s 100 watt power limit, that\u2019s still way too much. <\/p>\n\n\n\n

Compare this to a truly legal and FCC certified Part 15 FM transmitter<\/a> from the radio company C.Crane. The company states in the product\u2019s FAQ that,<\/p>\n\n\n\n

Most of our customers achieve 40 – 60 feet depending on their situation. The signal will travel up to 70\u2019 under good conditions. <\/p><\/blockquote>\n\n\n\n

That\u2019s less than a tenth the distance the Amazon until promises.<\/p>\n\n\n\n

C.Crane doesn\u2019t list their transmitter\u2019s output, only specifying that it measures at \u201cthe maximum allowed by the FCC.\u201d Though if we just look at the power consumption of 22.3mA and the fact that it runs on two AA batteries that provide three volts, then we can safely estimate it consumes less than a tenth of a watt. It most certainly transmits only a fraction of that.<\/p>\n\n\n\n

What this means is that there is no way the Amazon half-watt transmitter is legal to use under Part 15 regulations, and the likelihood that it\u2019s actually FCC certified is about a snowball\u2019s chance in Hell. However, the fact that transmitters like these sell for about $100 and have the patina of legality probably means there are dozens, if not hundreds of churches and other well-meaning organizations using them all over the country. I wouldn\u2019t be surprised if even just one of Rep. Green\u2019s constituents has fired one up on Sundays, and maybe got tipped off that they could run afoul of the FCC.<\/p>\n\n\n\n

The Challenge of Expanding FM Part 15<\/h3>\n\n\n\n

It\u2019s not surprising that Chairman Pai recently denied Rep. Green\u2019s request<\/a>. In effect, he writes that the existing regulations are there for a reason, and that applications for licenses require proof that the proposed station would not interfere with existing ones. <\/p>\n\n\n\n

I certainly would love to see a more robust legal unlicensed radio regime in US. Ideally it would be like New Zealand\u2019s<\/a>, which reserves a few frequencies for transmissions up to a one watt of power. I\u2019d even settle for something tinier.<\/p>\n\n\n\n

That said, I can actually empathize with the FCC on this one. The Part 15 rules are set under law; any changes would be difficult and slow. An attempt to provide waivers would result in howls of protest from the broadcast lobby, who are already in a tizzy about the rampant pirate operators in places like Brooklyn, Boston and South Florida. <\/p>\n\n\n\n

I can also imagine the waivers would be challenging to enforce. Without a license to revoke, how would the FCC ever verify that anyone is keeping to the new limit, without basically further stepping up overtaxed field enforcement operations? Moreover, there aren\u2019t commercially available FCC certified transmitters that would fit the bill. I doubt the Commission would want to tacitly authorize the currently-illicit transmitters that are all over online marketplaces.<\/p>\n\n\n\n

Of course, a Sunday morning half-watt broadcast on an otherwise empty frequency in a small Tennessee town is unlikely to generate much harm, nor much attention. There are relatively few FCC field agents, and it\u2019s hard to guess how many would enjoy spending their Sunday mornings cruising around looking for churches to bust. That doesn\u2019t make it any more legal, and I\u2019m not advising any law-abiding house of worship do this. I\u2019m merely assessing the real-world risks. <\/p>\n\n\n\n

Yet I would also agree that there\u2019s a slippery slope from the well-meaning, conscientious and non-interfering broadcaster to the also well-meaning, but more loosey-goosey operator who decides to go for even more power, or to try squeezing their station onto a frequency that really isn\u2019t that clear. On top of that, I understand that a lot of the transmitters you can get online put out a pretty dirty signal that cause additional interference by \u201csplattering\u201d onto adjacent frequencies. Using one responsibly is difficult or \u2013 as some would argue \u2013 impossible.<\/p>\n\n\n\n

It takes knowledge, research and skill \u2013 and proper equipment \u2013 to broadcast cleanly above Part 15 limits without causing problems. So, caveat emptor.<\/p>\n\n\n\n

Ultimately, this is why the Part 15 rules exist, even if some might argue that they\u2019re too conservative and stringent.<\/p>\n\n\n\n

Legal Unlicensed Part 15 Options Abound<\/h3>\n\n\n\n

That doesn\u2019t mean churches, theaters or other organizations can\u2019t leverage Part 15 broadcasting. As I mentioned earlier, there is a whole industry around manufacturing well-engineered and reliable transmitters, particularly for the AM band, where the achievable distances are greater. Despite the AM band\u2019s diminished reputation, you can still get very good sound for voice and many kinds of music. Plus, the vast majority of cars still have AM receivers built in, which are also well optimized for the band.<\/p>\n\n\n\n

Hobby Broadcaster<\/a> should be the very first place you visit, where proprietor Bill DeFelice has done the hard work of testing and reviewing transmitters and writing guides for broadcasting legally and effectively without a license. We talked with Bill on episode #120 of our podcast<\/a>, and I humbly suggest it\u2019s a must-listen if you\u2019re thinking at all of getting into Part 15 broadcasting. <\/p>\n\n\n\n

Radio World also published a series of editorials and letters on Part 15<\/a> this summer, which might be of interest to the more technically minded. <\/p>\n\n\n\n

Admittedly, the better FCC certified Part 15 AM transmitters are quite a bit more pricey than the sketchy FM ones on Amazon. You can expect to pay anywhere from $700 to $1000 for something like a Hamilton Rangemaster<\/a> or ChezRadio Procaster<\/a>.<\/p>\n\n\n\n

But I\u2019m also happy to report that the venerable Talking House transmitter<\/a> \u2013 originally designed for real estate agents \u2013 can be had new for around $130. I own one of these that I use for my own tiny Part 15 broadcasts, transmitting experimental radio sounds to the surrounding neighborhood and passing cars. Using the stock antenna and very little optimization I can get the signal about a block away on a portable radio (that\u2019s just 200 feet here in Portland, Oregon<\/a>). In a car I\u2019ve heard it faintly as much as four blocks away when the wind is blowing just right. That performance meets my expectations, and it sounds just fine for what I\u2019m doing. <\/p>\n\n\n\n

We at Radio Survivor love a tiny radio station. We\u2019ve written and podcasted about the topic many, many times. If your interest is piqued, dig into the world of Part 15 with us:<\/p>\n\n\n\n