Limited Area Broadcasting

I’ve just spent a little chunk of time plowing through the archives of the Low Power Radio blog, which I found through my referrer logs. It promises insight on “how to set up and operate your own low power radio station.” By low power, the blogger Kev means:

Micro radio, micro power broadcasting, part 15 radio, community radio, neighborhood station, experimental broadcasting, hobby broadcasting – I love it all!

It’s primarily a pretty good compendium of annotated links that’s been going with a few posts a month since February. Indeed, I found info about many more part-15 low-power transmitters for both AM and FM than I knew were available. There’s been a community of so-called “legal” low-power broadcasters in the US for a very long time. Many enthusiasts and broadcasters have been congregating for years at a message board called “Community Radio USA”. One of the denizens of that board has his own site called HobbyBroadcasting.net HobbyBroadcaster.net, which I found while reading through the Low Power Radio Blog.

While here at the ‘geek the focus is often on unlicensed broadcasters operating with power above the part-15 limit (roughly 100 milliwatts or so), there’s much utility to be found with part-15 stations, especially in dense urban areas or similar circumstances. Since FM part-15 limits are based on field-strength it’s relatively difficult to build a station with much reach that remains truly legal — even if you pump only 10 milliwatts into a very efficient antenna several hundred feet off the ground you’ll likely be reaching further than part-15 regs allow.

However, AM limits are specified in antenna length and power (100 milliwatts), allowing much more room for creative engineering and getting more broadcast range without breaking the law. Kyle Drake’s excellent LPAM handbook is a great reference for anyone wanting to try out legal part-15 broadcasting on the AM dial.

Much of the info that the Low Power Radio blog has dug up is more historical in nature, culled from both internet and print sources, like this 1991 handbook for starting a station. While the references to equipment manufacturers and sellers may be outdated, there’s still some decent tech and historical info to glean. I’m glad that someone is compiling and sharing this stuff and I hope that the blog sticks around a while.