New to Part 15 Radio, can someone help!?

Hi Brendan.. You should get a lot of responses and help here but I'll start. Part 15 refers to the rules for unlicensed radiators (transmitters) for legal low power operation. These transmitters come in many frequencies and types from car key systems to home portable phones and toy remote controlled cars. The part of part 15 we are interested in is refering (for the most part) to the am and fm broadcasting bands. Part 15 operation is NOT pirate operation. I don't know what movie you saw but Illegal operation carries a $10,000 dollar per day fine and potential for jail time. It seems like pirate operation is a good freedom type of activity but it is actually very anti social and selfish behavior and most of us here try to avoid that and comply with the rules. Please note that I'm not defending the mess that commercial broadcasting has become but if the rules and the operation of licensed operation needs changing that is provided for in our political system. Anyway I don't mean to rant but there are many good reasons for regulating transmitters including interference to other users and the limited number of frequencies available.
Now all of the for-going being said, much of the discussion here is about how to bump right up against the rules or interperate them because the broadcasting hobby is very limited in range by part 15. You should find and read the part 15 rules and then search these forum discussions for information about what is going on in legal operation.
My opinion is that the best way to start is not by immediatly figuring on "saving the world" and putting a bunch of transmitters on the air and bringing the community together etc. etc (hundreds have tried and failed), but instead read a lot here and elsewhere and maybe build a transmitter like the SStran (see the left sidebar) and pay your year or two dues getting your station running to learn what you need to know. If you think you wish to actually become a real broadcaster find a job at a radio station or earn the big bucks somewhere to buy one. Good Luck! Dave

Welcome Brendan,

There are many variables. Please state your goal. Until then ... very basically ...

1) Check the very front page of this site for a brief description of Part 15 radio.

2) FCC PDF located here:
http://www.fcc.gov/Bureaus/Engineering_Technology/Documents/bulletins/oet63/oet63rev.pdf

3) Simplest system: Part 15-compliant transmitter/antenna system and an audio source. It can be home-brew, kit, or pre-built and even certified system. The rest depends entirely on what type of broadcasting you want to do. It can be just sending music in and/or around your house, or maybe your immediate neighborhood, apartment building, school campus, etc. ... up to multi-unit synchronized system.

4) For AM broadcast band, range is dependent on a number of variables ... things like output power (always less than final stage input power ... max 100 mw), type of antenna (max length=3 m or 10 ft including antenna, transmission line, and ground lead), antenna tuning, ground resistance (highly variable), proximity to conductive surfaces, height, etc. I'm afraid there is really no such thing as "typical" broadcast range. Therefore no one can predict what your range will be at your location with your system ... could be just to your back yard or to perhaps a mile or so.

AM BCB has better range but is prone to RFI, basically travels on the ground during the day and can have skywave at night (which is why commercial licensed AM radio stations have to reduce power dramatically at night to avoid interference between stations on the same frequency).

FM typically has considerably less range, but is not as prone to interference, is line-of-sight, has better audio frequency response capability. Part 15.209 for broadcast band FM has hard limit field strength (emission peak) rules.

Part 15 transmissions cannot interfere with transmissions of licensed stations. Means that if you want to broadcast Part 15 radio, you need to find an open frequency in your area.

Cost is also wildly variable. You can scratch-build from circuit plans or sometimes find a Talking House unit on ebay for about $30-50, buy a very nice kit like the SSTRAN (see the ad on the left side of your screen), or a prebuilt low-end TX unit for less than $100 ... and up to an all-in-one certified system for $800-900, like the Hamilton Rangemaster 1000 (lower right side of your screen).

5) Depends what you mean by "ready for use". An AM transmitter might have a wire antenna included (or not), an FM transmitter might have a wire or a telescopic antenna. A complete certified AM system typically has a loaded CB-type whip antenna. Whatever it is, if it's certified, although you can tune it (every location is a little different for a given frequency), you can't otherwise alter it without losing its certification.

6) Part 15 radio in our case means FCC Title 47 Part 15 regulations. Of course it's legal as long as you operate to the best of your ability within those rules. You need to know what they are. But unfortunately some portions of Part 15 rules are a bit ambiguous, which leaves compliance in the hands of FCC field agent policies and judgement calls. They have detection gear which is priced out of the financial range of most Part 15 operators.

IOW, if you are going to be in the public eye, then make friends with your local field agent(s).

NOTE: The FCC, like the FAA and virtually all other Federal agencies, is run by un-elected officials. Policies can change with the current leaders, rules themselves can change with legislative actions. E.g., the Low Power FM Community Radio Act of 2009, House version passed and Senate version ready to pass, opens the doors for more licensing.

That's a good thing. Both versions are well-written bills.

But LPFM Community Radio stations are limited to two sets of ops, 10 watt max and 100 watt max, cannot be owned by an individual, cannot operate commercially, i.e., must be owned by an NPO, and cannot cause radio interference with commercially licensed stations.

On the good side for Part 15, with the exception of the last item, unlicensed Part 15 radio doesn't have the other restrictions ... because the extreme propagation restrictions are considered to be enough to keep it from having an impact on commercial or even LPFM station revenues.

For the group: If there flaws and/or omissions, please speak up. I'm kinda new myself, although I probably have several hundred hours of research, am writing a business plan, opening an internet radio station next week, and am preparing to get a General Class ham radio license.

I just saw no replies to Brendan's queries, so I thought I'd stick my $0.02 worth in hopes of getting him off on the right track ... if it's what he wants to do.

Good Grief, Charlie Brown! ... All that and then I blew the Subject line. No idea how that happened ... it should of course be: "RE: New to Part 15 Radio, can someone help!?"

Sorry :/

Pirate radio is the when a person or group of people operate a radio station that is using way too much power.

On part 15 we are allowed :
100 mW on A.M. 530 - 1700 khz
A bit less on FM 88 - 108 mhz
(if you choose fm, then try to use a certified transmitter)
See post http://part15.us/node/2006

As long as we stay within that power level we can operate legally as a part 15 operator. no license required.

Pirate stations operate with power levels of 5, 10, 25 even 1000 watts of power without a license which is illegal in most countries.
Some even cause interference with public safety services
(fire, rescue and aircraft communications).
I say some because there are some pirates that operate a clean station despite the fact that they are indeed breaking the law.

FM and AM is are not the only modes we can use under part 15 rules but they are the most popular. Other modes are shortwave, longwave, 46-49 mhz and many others.

The FCC rules can be a bit confusing if you are new to the hobby but never fear, this is a great place to start asking questions and learning about this fascinating hobby.

As mentioned in this thread, the SSTRAN, Hamilton Rangemaster and Procaster are the top notch transmitters for use in the AM broadcast bands. For FM there are many options but again, if you use FM at least try to use a unit that is certified.

Am is your best bet. Range is much greater than it's Fm counterpart.
As always if you need more help feel free to ask here or browse previous post on this forum and blogs.