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Radio Re-Volt: Broadcasting For The Common Man
An anonymous reader writes "Well, almost for the common man. This Wired article describes a project of the Walker Art Museum in Minneapolis to teach people about the power of radio through the use of cheap low-power FM transmitters. Although each transmitter is limited to a range of about a block, they're cheap enough that I could see them being spread out across a city to cover it with a signal. It'd be interesting to do something like that and feed these inexpensive networks via a netcast. You could use something like this to air programming that commercial stations won't broadcast because it's not commercially viable or because it doesn't fit in with the interests of big media. You can read the above article or go directly to the Radio Re-Volt Web site."
RHZ radio is already up and running and streaming content on the internet so that remote stations can rebroadcast it. Very cool stuff!
Signatures are a waste of bandwi (buffering...)
The relevant documentation can be found here
There's a product along these lines I've been interested in checking out.
It's called the "MP-308 Car USB / FM Transmitter", Here's a review of it.
Strangely enough, it seems to be the only Car MP3 player out there that takes a USB card - the discontinued "EMPEG" used to have such an input, but it's hard to get now. I've been wanting to use a nice cheap USB stick instead of CDs for the sheer convenience of popping it into the car and listening with an interface that's much more casual than CDs. Instead of plugging into the car's existing audio system, it works by sending out a short-range FM signal across the 87.7-88.7 dial (you select which subrange). That makes setup easy (so long as you have a good radio in the car), but I can't help but wonder how many radio markets have that FM signal open at that range, and what interference this would have with nearby cars. Fortunately, the device is fairly cheap to experiment with - you can find it for around $50 on pricewatch.
Ryan Fenton
CB radio consists of 40 different channels anyone can use.
Let me tell those of you who have not used a CB radio before, they are incredibly handy to have. I have a good setup on my car (although my transceiver just took a dive, will be upgrading that unit this next week!), and on the open highway in open country, you can send and receive a good distance.
A CB radio is the best "radar detector" money can buy. Truckers are always on the lookout for speed traps, and will continually call out the position of law enforcement officials, whether they're stationary or on the move.
Having a CB radio when you're traveling to places you've never been is also a godsend if there's some kind of detour, and you don't know your way around the area. Call out for directions, and a local driver will usually help you out.
CB radios are also nice in an emergency. There are decent people out there who will help someone when they're on the side of the road, and need help. At the very least, someone will be able to relay the message to law enforcement, or a tow truck or garage in the area.
Probably the best thing CBs are good for is helping one stay awake while on a long drive. It's always nice to be able to chat with someone to help you stay awake. Usually there's someone else looking for exactly the same thing.
CBs are a lot of fun, but keep in mind they are public channels. There are a lot of individuals who use incredibly foul language, and some truckers despise people in "four-wheelers", so you won't always get an answer to your questions. Be polite, though, and you'll find someone willing to chat or help out.
At best, your gear will be seized. If you're feeding your station with a computer, it will be seized, too. You may also face fines.
If your broadcasts cause interference to a licensed service and results in injury or loss, you could be held liable.
Using a transmitter kit mentioned by some of the other posters is also risky, even if they claim to be "legal" devices. I am not aware of any type-accepted hobby transmitters, and you will be personally liable if they do not conform to FCC rules.
I think the FCC should create a hobby service for low-power, non-commercial use. But that's not currently the case. Beware if you get involved in this movement.
http://pittsburgh.indymedia.org/news/2004/10/15699 .phpn dex.ph p/ 115 95/index.phph ive_by_id.php? id=1407&category_id=12
:
http://www.tnimc.org/feature/display/2762/i
http://santacruz.indymedia.org/feature/display
http://www.indybay.org/archives/arc
From http://pittsburgh.indymedia.org
" Two community radio stations, one in Knoxville, TN and the second in Santa Cruz, CA have been raided in the last 2 weeks by armed US Marshalls (and/or FBI) and the FCC. Last October, San Francisco Police and the FCC raided a popular Bay Area radio station. Despite the federal government's war on community media, radio activists across the US are operating community stations in open defiance of FCC regulations. The FCC strives to squelch community radio so that the airwaves remain free for media conglomerates like right-wing ClearChannel Communications, which owns 1,250 radio stations (six in Pittsburgh), and Viacom-owned Infinty Broadcasting, which owns 180 stations (four in Pittsburgh).
Also, in Pittsburgh, two broadcasters were shut down in the past week due to FCC intimidation. South Side Radio broadcasting at very low power on 102.9FM, and "WCSA Radio" in Plum, PA (Allegheny County, east of Pittsburgh near Oakmont). Indymedia Rustbelt Radio, our biweekly news program on (licensed) WRCT 88.3FM, will feature reports on these actions in Pittsburgh and around the US this week on Tuesday, October 5th at 6pm.
Next week the National Association of Broadcasters, a powerful lobby group, will meet in San Diego. In opposition to their corporate agenda, independent media activists will be holding a four day convergence of workshops, speakers, and actions to tell the NAB "We Want Our Airwaves Back!"."
Sugapablo
One could use icecast and reach globally - given one has the bandwidth to do so. On a normal DSL connection, however, you're limited to < 1MBit upstream. So, you could have (at most) about 8 people worldwide listening to your broadcast. THEN you have to worry about licensing fees if you're really thinking about setting anything viable up. I help operate at a 13-watt radio station at the University I work at. We are pretty popular in the radius of a few miles that we reach. Last year we added a Shoutcast stream that has proven pretty popular, but we had to limit the quality to 24k and the number of listeners so we wouldn't saturate the University's outgoing pipe. Bandwidth alone, we pay about $800/yr in licensing to ASCAP, BMI, SESAC, and SoundExchange for over-the-air and streaming rights. We're lucky, as an University, our streaming is often including in our over-the-air license and we don't have to pay per song played either. My point. Streaming is great, but there are still a number of hurdles to jump.
This isn't something that can be made into a "cluster." Either you have to put them far enough apart there are holes in the signal or you end up with overlapping transmitters just a few hz apart - essentially "stepping on" your own signal. Either that, or you'd have to ask your listener to retune every 500 feet to another channel so you got no overlap.
Actually, what you really do is tune them to the same frequency - as long as you're using FM. FM has the wierd property that if you have two FM stations transmitting on the same frequency, the stronger station is what's received with little to no interference. This phenomenon (the Capture Effect) results in you only hearing one station on your receiver.
Thus, all you really need is to keep all the transmitters on the same frequency, and the receiver will seamlessly switch among the microtransmitters. If there are slight errors, as long as they're within the error range acceptable to a receiver, the receiver will cooperate. Might as well exploit all potential advantages. Imagine a city-wide radio transmission using microtransmitters. Quite useful. The only problem is how to distribute the signal to the transmitters...
Section 15.23 of the FCC rules states that an individual may construct and operate up to 5 (five) such transmitters for personal use.
There's much better stuff out there than the Ramsey crap. Broadcast Warehouse, NRG, ...
And again, it's 100mW for AM. For FM, it's 250 microvolts/meter at 3 meters, and I'll bet you don't have a field strength meter to measure that.
There is a problem with using an internet technology for delivery, and that is licensing. Radio stations pay license fees to ASCAP/BMI, and the rates for noncommercial stations are very low. Also, broadcast stations are exempt from certain license fees due to an age-old agreement that views radio as helping to increase record sales. Well, internet-based media doesn't get those same deals.
There are certain parts of the bandwidth which are "off limits" to everyone, public or private.
Take a look here for some of the frequencies.
The idea is that, if we want to take clear radio-frequency "images" of distant images, it makes sense to avoid polluting the sections of the bandwidth where those images are to be found. No, I don't think any of these lower-power trasmitters will be broadcasting directly in these ranges. Unfortunately, most transmitters also transmit harmonics of their main frequency, at lower power. Consequently, everyone gives these frequencies, AND their lower harmonics, a pretty wide berth.
... by the Dew of Mountains the thoughts acquire speed, the hands acquire shakes, the shakes become a warning