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I hope this is the right place on Tribe to post this. Apologies in advance if it is not.
I know very little about radio technology other than what I remember from college and what I know from working with computer-related technology.
That said, I've for a while fancied the idea of a free-roaming, guerilla radio dance party:
1. The site is chose because it's deserted at the moment (a vacant lot, the beach, the financial district at midnight);
2. someone has a music source (DJ deck, laptop, ipod, whatever) and a transmitter.
3 Everyone is wearing radio headsets (like this: www.radioshack.com/sm-am-fm...049.html)
Otherwise it's like a dance club, except there's a lot more room and (hopefully) much fewer drunk people. The radio/headset setup allows everyone to enjoy the loud music without annoying the neighbors. If you want to talk to someone, they don't have to shout :-)
Why would I want to do this? I still like to go dancing, but the only places available are dirty, NOISY, crowded bars and I cannot deal with it anymore. Also I just think it's a cool idea.
I figure the broadcast area should be small, so it wouldn't need that much power. The receiver end is taken care of . And of course the having-a-party-in-a-public-space-without-a-permit is its own issue. I just need help with the broadcast part. And I wanted to know what you think.
I know very little about radio technology other than what I remember from college and what I know from working with computer-related technology.
That said, I've for a while fancied the idea of a free-roaming, guerilla radio dance party:
1. The site is chose because it's deserted at the moment (a vacant lot, the beach, the financial district at midnight);
2. someone has a music source (DJ deck, laptop, ipod, whatever) and a transmitter.
3 Everyone is wearing radio headsets (like this: www.radioshack.com/sm-am-fm...049.html)
Otherwise it's like a dance club, except there's a lot more room and (hopefully) much fewer drunk people. The radio/headset setup allows everyone to enjoy the loud music without annoying the neighbors. If you want to talk to someone, they don't have to shout :-)
Why would I want to do this? I still like to go dancing, but the only places available are dirty, NOISY, crowded bars and I cannot deal with it anymore. Also I just think it's a cool idea.
I figure the broadcast area should be small, so it wouldn't need that much power. The receiver end is taken care of . And of course the having-a-party-in-a-public-space-without-a-permit is its own issue. I just need help with the broadcast part. And I wanted to know what you think.
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SF Bay Area
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Re: Please advise me on this radio idea
Fri, September 14, 2007 - 6:37 PMHi Amy...
It's a cool idea, so long as you keep your transmitter power VERY low... like less than 100mW (1/10 of a watt), but likely lower.
The drawback? It just won't cover very far. You'll most likely be able to be heard by everyone within a couple hundred feet of your transmitter, but that's it.
Here's the official FCC ruling on this sort of thing...
from: www.fcc.gov/mb/audio/low...ml#UNLICENSED
PART 15 DEVICES
Unlicensed operation on the AM and FM radio broadcast bands is permitted for some extremely low powered devices covered under Part 15 of the FCC's rules. On FM frequencies, these devices are limited to an effective service range of approximately 200 feet (61 meters). See 47 CFR (Code of Federal Regulations) Section 15.239, and the July 24, 1991 Public Notice. On the AM broadcast band, these devices are limited to an effective service range of approximately 200 feet (61 meters). See 47 CFR Sections 15.207, 15.209, 15.219, and 15.221. These devices must accept any interference caused by any other operation, which may further limit the effective service range. For more information on Part 15 devices, please see OET Bulletin No. 63 ("Understanding the FCC Regulations for Low-Power, Non-Licensed Transmitters"). Questions not answered by this Bulletin can be directed to the FCC's Office of Engineering and Technology, Customer Service Branch, at the Columbia, Maryland office, phone (301) - 362 - 3000, e-mail LabHelp@fcc.gov.
I know, it sounds like a bunch of jargon, but basically you have to keep your output power extremely low to avoid any intentional interference.
Ramsey Electronics has a few good low-cost kits for this sort of thing, complete with literature outlining the FCC rules. Here's one of the kits...
www.ramseyelectronics.com/cgi-b...ce.exe
It would be a good idea to ignore the ramblings of the pirate FM operators in the bay area (and elsewhere) who will quickly say "fuck it" and tell you to just buy something higher-powered and ignore the FCC rules. Despite my political views and feelings about the FCC (I really don't agree with the FCC and side with "community radio" activists in most cases), getting caught isn't worthwhile, and can severely hurt your chances at getting a radio license should you ever decide to become a ham operator or (you never know) start your own legit radio station.
LPFM (Low Power FM) was created several years ago as a legal, low-cost way for community groups (churches, social clubs etc) to launch radio stations that were limited by 100 watts of power @ 100 feet in height for the transmitter antenna. Thousands of groups across the US launched their own radio stations when the rules and 'service' were put into motion by the FCC, and I even have a friend operating one of these in Scottsdale, AZ who has become very successful and has a huge listening audience. The stations would cover far enough to service a small city or rural area covering about 30-100 square miles depending on terrain and obstructions. Unfortunately, due to the overcrowded FM broadcast band in the SF bay area (according to the FCC), there just isn't any room for LPFM stations to be brought on the air within the band. Though I think the FCC's assessment that the band is overcrowded (it really isn't, another sore point I have with them), there isn't any legal way around this policy.
Ok... that's probably more than enough information. Keep in mind that your transmitter will only work as well as the antenna you use with it, and you DO need an antenna to make this little ensemble work well. The built-in antenna on the Ramsey kit is poor at best, but might be ok for the purposes of your project. If you want to know more about antennas and / or how to make a decent one, drop me another line and I'll do my best to help you out.
Good luck!
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Re: Please advise me on this radio idea
Mon, September 17, 2007 - 12:50 PMA hundred feet is half a city block, right? That shouldn't be too much of a problem. My vision for the party is fairly small. If it gets any bigger than that, I'd want to add another dj/broadcaster. -
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Re: Please advise me on this radio idea
Mon, September 17, 2007 - 10:38 PMThat's pretty subjective, but you've got the right idea! If you need to add additional transmitters, two things to keep in mind...
1. Having them on the same frequency (channel, etc) will make it easy for someone moving from one end of your party to another / in and out of one transmitter's range to the other. Be prepared for there to be a dead-spot or have instances of the transmitters interfering with one-another. This will happen when the coverage areas are overlapping, so you could end up with severely distorted audio being heard by those going between transmitters.
2. Having them on different frequencies will prevent them from interfering with one another. The drawback with that is it's annoying to change frequencies just because you walked 100 feet or so.
Remember, if you upgrade from the mediocre antenna that's supplied with the unit to something better (you can build a high-quality antenna for less than $30-40 in parts) you can easily double or triple your range without increasing your output power into the illegal range. For larger areas where you use multiple transmitters, it might be preferable to have a bit of a dead-spot between transmitters. You could have different styles of music on the same frequency that way.
Of course, there are other factors. With such low power output, the signal could be attenuated (drowned-out) by all the obstructions created by the people at the party. Regardless, just start w/ the kit transmitter and see how far you get. Honestly, if you're getting close to a full city block out of it, don't worry too much about the legality of it (in my opinion). I seriously doubt anyone would come after you, and since it's a temporary gathering, there most likely wouldn't be any opportunity for someone to complain. The nice thing is the FCC doesn't even act unless they get complaints about something from the public.
As always, feel free to ask away w/ more questions!
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Re: Please advise me on this radio idea
Thu, October 11, 2007 - 5:24 PMHAMs know a lot about radios & could help you, but what you are talking about is known as pirate radio there are tons of web site on the subject. -
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Re: Please advise me on this radio idea
Thu, October 11, 2007 - 11:53 PMi already touched on that aspect of this project in the thread. i've given her the information she needs to keep this legal and still make it work quite well. i advised her against going the pirate route as it's only trouble in the long run.
i've been down the pirate route already, and the trouble it causes you is more trouble than it's worth.
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