Just want to clear up what might be a slight misconception at least with regard to hobby broadcasting in the U.S. Hobby broadcasting is governed under FCC part 15 of the FCC rules and regs. These rules are summarized below. Thanks to the Ramsey Electronics Bulletin Board from which I copied this info.
Hello All, After you read my post, please do not respond with comments about "go for it", "relax and have fun", "you won't hurt anybody and won't get caught", or many of the other criticisms which have resulted when someone, such as I, explain the reality of the FCC rules regarding part 15 FM. My intent is not to tell anyone what to do or what not to do; it is to provide information so those who are interested can have a knowledge base from which they can decide on their own how to proceed. If I state technical or other inaccuracies, I will welcome and acknowledge corrections. The FCC rules for unlicensed operation in the FM band limit, among other things, the field strength to 250 microvolts per meter measured at 3 meters. This is not a limit on power, transmission lines, grounds, nor antennas. This limit actually includes the effects of all of these variables and focuses only on the outcome. To put this field strength in perspective, this field strength can be produced by about 11 nanowatts into a dipole antenna. One nanowatt is one one millionth of a milliwatt, so the information typically mentioned about 25 milliwatt transmitters is not only not presenting any meaningful information about compliance with the FCC rules, it is misleading people into believing that this power is the norm for legal hobby FM. A 25 milliwatt output delivered to a typical antenna will exceed the field strength limit by about 1400 times. Many have been cited and fined where the citations mention field strengths in the range of that which can easily be produced by 25 milliwatt transmitter output power. If you don't think this is something to consider, check these links (look for NOUO and NAL): http://www.fcc.gov/eb/FieldNotices/ http://www.fcc.gov/eb/Orders/Welcome.html You will see that there are many citations and fines for unlicensed operation on the FM band. You might think that the kit your built is OK but consider the information on the following links, especially with regard to the calculated "milliwatt" transmitter powers which resulted in FCC actions: http://part15.us/node/1375#comment-4249 http://www.part15.us/node/716#comment-1578 You might assume that because you bought a FM transmitter kit from a good source (such as Ramsey) that it is going to be legal to put it on the air. This is not true unless you can, by some means, assure that you comply with the rules. All of the FM transmitter kits of which I am aware are NOT FCC certified nor type accepted. It is legal to offer these for sale as kits, but the responsibility for legal use falls on the user. There is no assurance to be gained that you will not have a problem just because you bought and assembled a kit from a reputable manufacturer. It is up to you! I have a Ramsey FM transmitter and I have limited the range of this unit to less than 200 feet. Why? Because the FCC itself has published an information sheet which states that this is the approximate range to expect from a legal station. I have no other means to judge my compliance with the regulations, but this is probably close enough. You can achieve, with the kits available and simple antennas, much greater range but consider that you cannot do so legally in the US. A cavelier attitude on the part of those who operate FM transmitters built from kits and who intentionally or unintentionally violate the rules may result in, by a change in the rules, the complete elimination of FM transmitter kits from the market It is your choice regarding what you do. It is my hope, after you have read this, that you will do so knowing what is involved. Neil ----- Original Message ----- From: "Bob Seed" <[EMAIL PROTECTED]> To: "PC Audio Discussion List" <pc-audio@pc-audio.org> Sent: Wednesday, September 12, 2007 4:02 PM Subject: Re: Accessible FM transmitters > Oops, I wouldn't recommend going that route! There are very strict rules > governing FM broadcasting in the United States and Canada. Anything over 1 > watt requires a broadcast licence, and you have to ensure that the > frequency > that you are transmitting on is not being occupied by another broadcaster. > The FM transmitter that is being recommended on this site is more than > adequate to cover the average home. The seller of the unit is not > responsible for any modification done to the unit in order to broadcast > beyond the recommended coverage area. . > \ > From: "DJ DOCTOR P" <[EMAIL PROTECTED]> > To: "PC Audio Discussion List" <pc-audio@pc-audio.org> > Sent: Wednesday, September 12, 2007 12:42 AM > Subject: Re: Accessible FM transmitters > > >> Hello Russell,this is John. >> I have been doing some research on transmitters and amplifiers. >> You can take one of these transmitters that was designed for home use, >> and >> hook it up to a 1000 watt amplifier. >> This will allow you to broadcast all over town, that is, if you wanted >> to. >> Based on this, I will try to set up my own gospel radio station, and run >> it >> out of my house. >> But however, for starters, the $340 fm radio transmitter with a 1000 watt >> amplifier witch will cost around $500, will do the trick for me. >> The Bose and or any radio will pick up a signal this strong. >> The thing that you may have to do, is get an FCC license to broadcast. >> This is something that I'm still trying to figure out how to go about >> obtaining. >> Just as soon as I find out how, I will post it here in pc audio. >> John Price. >> >> ----- Original Message ----- >> From: "russell Bourgoin" <[EMAIL PROTECTED]> >> To: "PC Audio Discussion List" <pc-audio@pc-audio.org> >> Sent: Tuesday, September 11, 2007 4:31 PM >> Subject: Re: Accessible FM transmitters >> >> >>> Hi Jonathan, >>> >>> I'm very interested in purchasing a unit as you describe in >>> your mail. When you say its priced on the high side, how high is >>> high? And, did they charge more for adding the features that you >>> requested? Is there a contact that you have to whom I could speak to >>> obtain a unit tricked out as is yours? >>> >>> I do some dejaying at fish and gun club functions. Often I >>> bring a few large bose accoustic waves and place them outside facing >>> the say, family day activities. The cooking crew is off at the >>> barbecue pit and are out of range of the bose radios that I bring, so >>> they park their trucks around the pit and tune radios >>> in. Unfortunately, they are out of reach of the c crane transmitter, >>> altered as it is. Hence my interest in the unit you describe. Any >>> info is surely appreciated. >>> >>> Rusty >>> > At 10:19 AM 9/11/2007, Bob Seed spake thusly:- >>>> couple of months ago, there was a great thread on this list about FM >>>>transmitters. A user recommended the transmitter found at >>>>http://www.wavemach.com. >>>> >>>>I purchased one of these and am thrilled. The range is huge, the >>>>construction solid, no nasty power hum, very good stereo separation, in >>>>short, no complaints whatsoever. I got him to add a level control that >>>>allows me to set the line in for the two RCA sockets, and he also added >>>>small buttons for setting the frequency. It has a standard antenna >>>>socket >>>>at >>>>the back and comes with a very solid little antenna, not just a wire. >>>> >>>>So if you're looking for an FM transmitter, this one is definitely worth >>>>a >>>>look, but it is on the high end of the price range. You definitely get >>>>what >>>>you pay for though. >>>> >>>>Jonathan >>>> >>>> >>>>----- Original Message ----- >>>>From: "Jason Boston" <[EMAIL PROTECTED]> >>>>To: "'PC Audio Discussion List'" <pc-audio@pc-audio.org> >>>>Sent: Monday, September 10, 2007 1:26 AM >>>>Subject: Accessible FM transmitters >>>> >>>> >>>> > Hi all, >>>> > I'm looking for a blind friendly FM transmitter that will work well >>>> > with >>>> > PC, stereo, mp3 player, etc. It also needs to be able to broadcast >>>> > 150+ >>>> > feet in a household environment. This is for use in the USA, so the >>>> > broadcasting frequencies need to end in odd numbers. >>>> > >>>> > I also would like the transmitter to have multiple power supply >>>> > options >>>> > like car adapter, AC adapter, batteries, even USB. >>>> > >>>> > I've seen one called MobileBlackBox v5000 fm transmitter, but it >>>> > seems >>>> > to be out of stock and I don't know how easy it is to use. Also, I >>>> > don't >>>> > know if it lives up to the range it claims. I know the one you can >>>> > buy >>>> > at Radio Shack for about $30 isn't worth 2 cents. >>>> > >>>> > Well, thanks in advance for your input and advise. >>>> > Jason >>>> > >>>> > No virus found in this outgoing message. >>>> > Checked by AVG Free Edition. >>>> > Version: 7.5.485 / Virus Database: 269.13.12/997 - Release Date: >>>> > 9/9/2007 10:17 AM >>>> > >>>> > >>>> > >>>> > >>>> > Audio List Help, Guidelines, Archives and more... >>>> > http://www.pc-audio.org >>>> > >>>> > To unsubscribe from this list, send a blank email to: >>>> > [EMAIL PROTECTED] >>>> > >>>> > >>>> > -- >>>> > Internal Virus Database is out-of-date. >>>> > Checked by AVG Free Edition. >>>> > Version: 7.5.484 / Virus Database: 269.13.2/983 - Release Date: >>>> > 01/09/2007 >>>> > 4:20 PM >>>> > >>>> > >>>> >>>> >>>> >>>>Audio List Help, Guidelines, Archives and more... >>>>http://www.pc-audio.org >>>> >>>>To unsubscribe from this list, send a blank email to: >>>>[EMAIL PROTECTED] >>>> >>>>__________ NOD32 2522 (20070911) Information __________ >>>> >>>>This message was checked by NOD32 antivirus system. >>>>http://www.eset.com >>>> >>>> >>>> >>>>__________ NOD32 2522 (20070911) Information __________ >>>> >>>>This message was checked by NOD32 antivirus system. >>>>http://www.eset.com >>> >>> "For everything that lives is holy, life delights in life." >>> (William >>> Blake) >>> >>> >>> >>> >>> Check out my site at: >>> http://www.thesoundzone.com >>> >>> >>> >>> Audio List Help, Guidelines, Archives and more... >>> http://www.pc-audio.org >>> >>> To unsubscribe from this list, send a blank email to: >>> [EMAIL PROTECTED] >>> >>> >>> -- >>> No virus found in this incoming message. >>> Checked by AVG Free Edition. >>> Version: 7.5.485 / Virus Database: 269.13.14/999 - Release Date: >>> 9/10/2007 >>> 5:43 PM >>> >>> >> >> >> >> Audio List Help, Guidelines, Archives and more... >> http://www.pc-audio.org >> >> To unsubscribe from this list, send a blank email to: >> [EMAIL PROTECTED] >> >> >> -- >> No virus found in this incoming message. >> Checked by AVG Free Edition. >> Version: 7.5.485 / Virus Database: 269.13.14/999 - Release Date: >> 10/09/2007 5:43 PM >> > > > > Audio List Help, Guidelines, Archives and more... > http://www.pc-audio.org > > To unsubscribe from this list, send a blank email to: > [EMAIL PROTECTED] > Audio List Help, Guidelines, Archives and more... http://www.pc-audio.org To unsubscribe from this list, send a blank email to: [EMAIL PROTECTED]
