Need help from some radio experts....

[Darkhawk32]

Need to know how and if it's possible to set up a series of low-power FM radio transmissions (all using same frequency of course) to cover a town of 100,000.

I plan on running free-to-use, permission-granted liberal radio programs or speeches to help get out our message.

This is definitely a thought in progress. I know that low-power FM transmissions do NOT require a FCC license. Let me know what you think.

[bonzotex]

1. possible, but maybe expensive

You'd need a lot of transmitters and antennas. At least one per square mile ...more or less depending on topography and signal wattage. Also where does the main feed come from? Either each transmitter has a set content to broadcast simultaneously or you use the transmitters as repeaters to pass on the signal from a base station or perhaps from a cable/Internet feed , Definitely doable, but you need a network of committed people, separated over the city geographically who are willing and able to host the T/Rs and antennas.

[Darkhawk32]

4. Aye, it would definitely be a collective effort.

I know there are computer-based FM transmitters that may be workable. It was just a thought, not sure if it'd be worth it.

[rawtribe]

2. From the FCC

http://www.fcc.gov/mb/audio/lpfm/

This page contains information about the Low Power FM (LPFM) radio service, which was created by the Commission in January 2000. These stations are authorized for noncommercial educational broadcasting only (no commercial operation) and operate with an effective radiated power (ERP) of 100 watts (0.1 kilowatts) or less, with maximum facilities of 100 watts ERP at 30 meters (100 feet) antenna height above average terrain (HAAT). The approximate service range of a 100 watt LPFM station is 5.6 kilometers (3.5 miles radius). LPFM stations are not protected from interference that may be received from other classes of FM stations. A construction permit is required before a LPFM station can be constructed or operated.

LPFM stations are available to noncommercial educational entities and public safety and transportation organizations, but are not available to individuals or for commercial operations. Current broadcast licensees with interests in other media (broadcast or newspapers) are not eligible to obtain LPFM stations.

<snip>

In general, LPFM applicants may only apply for a single station. However, on reconsideration, the Commission clarified that government public safety and transportation organizations may apply for multiple LPFM stations for disseminating traffic, safety, and other information where the additional applications are not subject to competing applications. Similarly, where there are no conflicting applications, LPFM applications will be accepted for university student-run LPFM stations from universities holding LPFM licenses that are not student-run. Separate college campuses within a university system, or individual high schools under a single school board, could each individually apply for LPFM construction permits. ITFS (Instructional Television Fixed Service) stations run by universities and colleges that only transmit educational programming are not considered a "broadcast service" under the FCC ownership rules.

[rawtribe]

3. Delete

[REACTIVATED IN CT]

5. The Nation May 23rd Edition had a story on LPFM

If you can't see the article on-line, try googling The Prometheus Radio Project. According to this article, they are "a clearinghouse for technical, organizational regulatory and financial information".
Pete Tridish "gives advice to the scores of community groups that applied for LPFM licenses in 2000 and 2001 but whose application are still stuck in the FCC bureaucracy".
The article does not list a website or contact info - unless I am missing something

[stevedeshazer]

6. Low power FM stations DO require an approved construction permit

What you're talking about is pirate radio.

It can be done, but not legally.

[benburch]

7. Less than 100 Milliwatts is BRC, Below Regulatory Concern.

I have a 100 Milliwatt FM rig; It gets to the corner.

You would need one in every block at least. More in cities where buildings would interfere. And if you wanted to have them all on the same frequency, you would need a fairly expensive crystal controlled rig with a "crystal oven" to ensure that each rig was close enough together that you could cross the boundary between transmitters without re-tuning a PLL receiver. And you would have immense problems with multi-pathing, I *think* but I'm not sure about that.

Good idea, but licensed LPCR is an even better one.

[Darkhawk32]

8. Yes, I think LPCR is the way to go.

I was getting LPCR and BRC confused.