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Posts
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Hi all,
After doing a lot of research over the last few months, I decided to put together something that we can use to start writing a formal proposal to the FCC. My goal in this is to allow people to broadcast to their community, but not too far past it. My town is about 1-1/4 miles across, so the power needed to broadcast from the center of town is not too much past Part 15 regulations, but still past Part 15 regulations. More on that below.
One common theme I’ve seen with hobby broadcasters is that most want to have what I call ‘serious fun’ on the dial, and some want to serve their community. It’s impossible to do with today’s Part 15 FM regulations, and AM is pretty dead (let’s face it, it really is). My friend bought a new car and his radio didn’t even have an AM tuner. If I felt AM was viable, I’d just get a Talking House and be done with it.
There’s a spot on the FM band that can be used as the basis for CLPFM: 87.9. However, how do you deal with multiple people in the same area that want to broadcast? My idea is very simple: allow people to request a CLPFM CP on a frequency in their town, and adjacent towns have to use something else. Maybe I use 87.9, someone in the town over has to use 88.1 if it’s available, or some other clear frequency.
I did some math trying to determine what strength I have to reach in order to hit the furthest point in town. It’s 1.1 miles away, but I don’t want to go any further. Unlike blatant pirates that want to broadcast as far as they can, I want my signal to be in the confines of my town. However, I’m not in the center of town, but that’s a different issue.
Using the formula E=(sqrt(30*P)/D), I solved for P and came up with P=( ( (sqrt(30) * E * D) / 30) ^ 2). The current legal field strength for Part 15 FM is 250uV/m @3m. Plugging 0.000250V for E and D=3, I get P=0.00000001875 watts. This next part is a bit questionable because I don’t know the sensitivity of a car stereo. I found that it’s supposed to be 5uV, but I don’t know if that’s true. Assuming it is, using 0.000005V for E, and D=1000 meters, the necessary power would be 0.0000008333 watts. Plug that back into the formula to solve for E, and we get that with that power, the field strength to reach 1000 meters would be 0.0016666 or 1666 uV @3m. Not so bad of an increase from the 250 uV limit. The problem arises with different towns. My town is small. A few towns over is a large one. Field strength can be strictly based on the size of the town. Maybe 1666 uV for me, 2000 for another town, 800 for another town.
Allow people to pay for an annual CLPFM license, and make sure they stick to the same rules that larger stations do: require stations logs. Applicants can be individuals or non-profits, but not large corporations. Allow individuals to use their station as a legit business like a newspaper or other media outlet.
This is a rough brain dump. There’s a lot more that needs to be taken care of. With all this talk about proposing something to the FCC, I thought I’d get the ball rolling. Let me know what you think.
Total posts : 45366Its a good start, but we need this CLPFM to be useable bo a rubber duck because not everyone can put up an outside antenna. I know @ ground floor @ 500mW you can get 1/4 mile on a Digital Car Radio and a little less on a Digital Boom Box. I propose 700mW to 800mW just under 1 Watt as I feel the FCC will see this is Oh its still less than a Watt. If 500 mW can reach 1/4 mile on a rubber duck @ ground floor I Shurely know that 1 Watt will get you a Mile on a Rubber Duck maybe a little more and that is fine for me to have serious fun. 2 Watts on a duck would go 2 miles. 3 Watts maybe 3 miles. But again you don’t want to go too much higher than 1-3 Watts because of the cheap clock radio’s and Radio’s that don’t have good filtering. If we can only get close to a Watt and see how that performs first as a study to the FCC I think we’re doing OK. Keep in mind that the “Secret High Power” mode of the Whole House FM Transmitter 3.0 is close to 1 Watt. So most of you won’t have to buy a new transmitter just flip the secret High Power mode on and your Rocking when its legal. I think there may have been proposals in secret that we don’t already know about and ours will only help to enhance this. Please lets think about getting close to the 1 Watt limit somehow we’ll have to figure that in a formula for a rubber duck and the field strength of 1 Watt for people like me who can’t put up an outside antenna.
Total posts : 45366I think that the initial proposal is a good start.
But the math and initial assumptions need a bit of reworking. Car radios have sensitivity in the 2-4 uv range (some even better) but home radios would be 15-25 uv or worse. I would imagine that you would want to reach home radios. And you need to take into account obstructions – even getting into people’s homes reduces the signal.
All that adds up to the 1600uv/m at 3 meters being too light. I know from experience that I was able to get 1km range to excellent car radios (probably about 1.5uv) line of sight. But that was a very weak signal, and any obstructions at all would cause the signal to drop out – luckily my intended audience was stationary cars in a ferry lineup (which minimized dropouts).
So my quick rough guess is that for a mile range, your’re going to need double the 1600 to get to car radios, maybe 5 times that again to get into homes, and a fudge factor for obstructions. So even not allowing for obstructions, the field strength needs to be 16,000uv/m at 3 meters (around 0.1 milliwatts). 1 milliwatt would probably do it, and whatever field strength that entails. You’re going to get more than a mile range to a car, but you’ll likely be able to hit most of the homes in your town. Of course, you’d need a good, elevated antenna.
There’s no way that the FCC is going to allow anything close to 1 watt, in my opinion. If you can get big range with a rubber duck antenna, you’re going to go miles and miles with a good one (and someone is going to use a good antenna whether they’re supposed to or not).
Total posts : 45366Unless the transmitters are matched for the Rubber Duck. The Rubber Duck could have a chip in it similar to car keys. If the code is not found the transmitter would drop to the -48DBm which is about what we have now. I think we need to think of folks who don’t or can’t put up an outside antenna. I don’t know how you get the 1mW formula cuz I know it took 500mW for a friend of mine who was experimenting in the country and he was inside a wood house and had the TX Next To A Window and done short bursts of of on air to see how far he could transmit on 1/2 Watt with only a rubber duck. Again to a car Radio he was reachable @ 1/4 mile. To a boombox less than that.
Something else to cinsider is technically its illegal to put your part 15 TX into anything other than its stock antenna (Not that I Care or world Narc) just for FYI. With that in mind yes I’m sure some could figure out how to connect an outside antenna to it, but again those folks would have to deal with the FCC if they were to come to their home. If you are gonna consider someone having an outside antenna then the limit should be in RF Power to the final of the TX and not the field strength in the first place. We’re trying to get a decent range of say a mile or 2 at most. Reason I say this is that its a reasonable shoot since the FRS Walkie Talkie’s and MURS Radio’s around 1 Watt travel that far on just the stock Rubber Duck. Its why I think if we can shoot for the same power/range on FM it could be reasonable as proof is already there for MURS. We should at the ALPB get a 1 Watt waiver to allow for this study to see how a 1 Watt or stages below will perform. However I think the 500mW to 700mW would still be allowed after the tests are said and done.
Total posts : 45366Several discussions are taking place right now based on a preference for FM sound quality and a strong interest in using 87.7 and 87.9 MHz because of the crowding on the rest of the FM band.
I just found a station in Smithfield, Rhode Island, licensed for 1.2 kW at 87.7 MHz. Even though the station appears on radio-locator.com, that same website claims that 87.7 is not a valid frequency if the search is done for that frequency.
KSFS in Mountain View, California, is licensed for 10 Watts on 87.9 MHz.
The whole FM land-rush is causing a lot of congestion and change.
Meanwhile I was listening to the Chicago Lyric Opera on AM radios located in every room of the house, and amazed how good it sounded, which reminded about NRSC Pre-Emphasis, a feature defined by the FCC to enable AM stations to compensate for the high-end roll-off caused by radio receivers, restoring FM-like audio quality to AM.
Our AMT5000 and AMT3000 all have NRSC Pre-emphasis as a built-in option by setting a jumper, and this discussion on the subject comes to mind:
http://www.part15.us/forum/part15-forums/brain-power-and-ss-trans-ex-antenna?page=1
Total posts : 45366Quote from Thelegacy: “Something else to cinsider is technically its illegal to put your part 15 TX into anything other than its stock antenna…”
Actually, it is not illegal. This requirement applies to certified equipment and will result in loss of certification if the supplied antenna is not used. Of course, illegal operation may result if the field strength limit is exceeded by doing this.
It is refreshing to see some science applied by macdev to attempt prediction of performance of FM Part15 transmitters. There are a lot of unknowns which affect this but this is a good start.
Regarding using a “Rubber Duck” antenna, these are lossy. The difference between this antenna and a reasonable gain antenna can be on the order of 12 dB of radiated power. Such a situation brings us back to specifying a field strength limit at a distance rather than power. I believe Thelegacy understands this because he has mentioned a specific antenna used with a specific transmitter which could be certified as a system to meet regulations.
The more we discuss these ideas the more we learn and our thoughts will converge on a meaningful goal to pursue.
Neil
Total posts : 45366I did the math becasue that’s just my background. Math and physics. I don’t blindly accept people’s answers, I have to understand it myself. Like when people say “part 15 FM can’t go X feet”, I think “hmmm….well, that depends on a few factors” and then I do the math. I don’t like myths.
In any case, I had two other points in my head: how LPFM people would feel about these kinds of stations, and enforcement. Right now, I can’t hear a local LPFM station because of these jerks a few miles away stomping all over them. It’s annoying. The FCC sent them a letter, but they still broadcast. And this is right across the river from NYC in NJ. I don’t know if the FCC is ever going to do anything about it. We could get CLPFM approved and then deal with people like that.
As for LPFM itself, I’m not happy that the window opens every 15 years. I just learned about it and there’s nothing I can do except broadcast over the internet. Sure, I can do that, but I would rather do both. Legally. Radio is still big, at least in this area.
I’m also trying to figure out whether the FCC would be open to this sort of thing. It took over a decade for LPFM to get their window opened. Is this going to be another 15-year conversation?
The idea seems harmless enough – community radio for a small town. Maybe I’m too optimistic about it, but I think we can make it work so long as we can prove that it’s useful. I know the corporations aren’t going to like it, but I’ve watched radio go from a great band of music to a cess pool. There has to be a way to bring it back.
And I think someone said it before – the FCC made this mess by allowing one company to own as many stations as they want.
Total posts : 45366That is not good to hear… about the 15-year gap between LPFM windows? That’s half-a generation!
But what about the predictable fact that some LPFM stations will be open to sell or just go out of business? Can they sell their license the way normal stations can? If so, that would be an opportunity to watch.
I read that sales take place involving higher power public stations, so courting a lot of rich friends might be the way to go.
Total posts : 45366Macdev mentioned small town examples but what if you are in a city? I think a fixed legal field strength is best…say1500 to 2000Uv/[email protected] so it doesn’t matter the antenna(rubber duck, telescoping like the decade etc outdoor, indoor). This is simpler and an even rule for all. this would give enough power for a small to medium neighbourhood and 87.9 should be legal.
A small fee could be imposed like $15 a month and you have to just inform the FCC (or industry Canada) of your frequency and where you are.
And what if you go somewhere for a vacation or weekend and want to take your station?…..maybe someone has a suggestion for that?
I would sign any petition for increasing the legal unlicenced strength.
Mark
Total posts : 45366Getting the neighbors to sign a petition saying they want a radio service for their community might make a better impression than just a bunch of different station owners.
The stations we have been talking about are stations we want to build but the neighbors do not know we are planning a station that will serve them. They are, in effect, phantom listeners. That is, they are the listeners in our perfect dream of wanting to be liked and accepted.
Maybe at some point actually “knowing the audience” would make good sense in planning a station.
I know my neighbors and they don’t think about radio because of their browsing, cell phone calling, texting, and spending large amounts of time out of range of the radio station.
Total posts : 45366Ok say you are using a rubber duck how much power equals 2000 uVm @ 3 meters? I think it should be 30 meters. How much for a telescoping antenna out of a TNC connector?
Total posts : 45366AM is dead? The hell you say. I work at a 5000 watt commercial AM station — been there for 27 years now. Our sales continue to increase, listenershp continues to grow, and we’re a long way from being dead. of course we do go out of our way to serve our community and provide actual live local programming. Heck we just installed a brand new transmimtter 18 months ago. Long way from dead. The reports of AM radios death is somewhat exaggerated.
In addition my Part 15 AM has been on nearly 2 years now. Zero downtime. Listenership continues to grow. I’m embarassed to tell you what revenues generated are but I will probably top $20,000 for 2015. My station reaches out 7100 feet solid into car and portable transistor radios, further out on the nearby lake chock full of watersports enthusiasts and fishermen. I do have the advantage of only a couple other AM stations in the area (including the one I work for) and being in the boonnies nearly zero man made interference.
No, sorry to report, AM is not dead.
“Require stations logs” Umm, this went out with button shoes and hand well pumps. At my commercial station we participate in a moc FCC inspection every 3 years. They don’t even look at transmitter logs anymore. The rule is, basically, that if they have a complaint of find you out of compliance you have to prove you’re not. Most modern stations now have a system where when a reading gets out of tolerance (too much plate voltage, too much plate current, too much antenna current, silence, etc…) there is an alarm, and the system is designed to telephone someone for help. We take transmitter readings on each shift just because I’m in charge and I’m old school, but the FCC doesn’t care. Our alarm system first calls the station, then me, then the PD, then the owner, then moves on to cell numbers and other employees. Gonna require EAS? Gonna require Equal Opportunity? that’s a HUGE PITA the stations. We have to PROVE that we have gone above and beyond to find minorities to work for us. OK, up here, there might be 4 black people in the area. We have to prove that we tried to recruit them. The paperwork for that is a huge issue. Gonna file quarterly needs and issues?
If you want a snowballs chance in hell of getting the rules changed to allow more powerful community broadcasting, one huge thing must be accomplished first. There MUST be a REAL, national organization of Part 15 broadcasters. A group that pays dues, has at least a quarterly publication, an FCC lawyer on board in Washington, and someone who can lobby the FCC. The ALPB is a nice start, but when you get down to it, it’s not going to pass muster as an actual legal organization of members. Get 90% of the Part 15 guys to join, including those who are on the “other” site and present a united effort. “1870 members of the ALPB (or whatever) petition the FCC for low power community broadcasting” is a heck of a better headline than “a few radio buffs get together to change the rules” You will immediatly face backlash from the NAB and RAB. OH, and how many of you cats are actually paying music licensing for your Part 15? Oh, we argue back and forth about it, but if your intention is for others to hear, you MUST. and you can be darn sure you’ll have to with any more power, and pay more than you have to now.
ALso we need to quit talking about coverage and figuring it based on your car radio. Every car is different, and few people sit in their cars and listen to the radio. If they’re driving they’re going to be in your signal for a very short time. Not a valid measuring stick.
Measure actual field strength. Yes, I know, it takes an expensive meter. I have two of them. Then you at least have a real, repeateable, accurate measure of what you’re putting out.
Anyway, there’s my random brain dump.
Tim in Bovey
Total posts : 45366OH, and I’m very curious to know — what kind of new car did someone buy (it was mentioned above) that did not come stock with an AM radio? As someone who does a LOT of advertising for local dealerships, and who hangs out at car places, I’ve yet to see a new car with no AM radio in it. Although we do only have “domestic” dealerships in the area.
Total posts : 45366Tim, you make some valid points. But I do have some comments. I am a member of the ALPB, but I’m purely speaking for myself here.
I agree with you that AM is not dead. As I’ve posted earlier, 2 of the 3 top stations in Vancouver (a rather sophisticated urban metropolis) in terms of listenership are AM. There’s a lot of life there yet.
I do have to disagree with you on getting 90% (or whatever) of the Part 15’ers to join a national organization. I would think that it will be extremely difficult to even measure that, never mind accomplish that task, given the wide spectrum of reasons for being in the Part 15 arena, from pure hobbyist and experimenter all the way to running a business.
Anyone with an interest in Part 15 radio , and who is willing to support the ALPB charter, is welcome to join. As for those guys ‘over there’, most to date have to shown no interest in doing so. I suspect because then they wouldn’t be able to run the show the way they saw fit (the ALPB is one of the most democratic organizations I’ve ever been involved with). I remember in the early days of the ALPB one individual who currently resides ‘over there’ showed up for a few meetings, but left when he couldn’t dictate how things would be done.
As for music royalties, the ALPB does not condone piracy in any form. As much as I’m aware, each member station either 1) pays the royalties in their country – the ALPB is international in scope – or 2) uses independent music for which they have the appropriate permission or 3) creates their own programming. There have been many discussions on the importance of music licensing and remaining legal (piracy can take many forms, not only technical).
I believe it is important for any formal petition to the FCC to identify the reasons why it would be beneficial to change the rules. For the public, for the FCC and even for the NAB. Although I suspect that there would be rote opposition from the NAB no matter what is proposed. A petition would have to be accompanied by the appropriate technical documentation, identifying what the rule changes would mean in terms of range, potential interference, etc. It would be no small amount of work.
Lobbying? Isn’t in person lobbying essentially a thing of the past? In these days of social media, much of the critical lobbying can be done there. A well designed social campaign can circumvent barriers that would almost be impossible to overcome otherwise.
It should be noted that, as far as I know, no decision has been made by the ALPB to submit a formal petition for rule changes to the FCC. There’s been a lot of discussion, and there’s going to have to be a lot more discussion and research before that decision can be made.
Why don’t you drop in at the next meeting, Tim? Any and all opinions matter.
Total posts : 45366There was a Radio Group that already fought for LPFM and the need for it. We at the ALPB are looking at them for help. Some of what you mentioned we talked about at out meeting. We did agree that more homework needs to be done on field strength as we figure about a mile to a home Radio (Digital). We’re trying to get some sensitivity reports for different Radio’s you can buy at say your local Walmart to try and get a range of about a mile and the correct field strength on FM on a Rubber Duck, Dipole and Telescoping antenna. Royalties? I know that my Internet station has been on air for over 7 yrs and we pay our royalties through StreamLicensing or http://streamlicensing.com and they divy the amounts to Sound Exchange, BMI, ASCAP, SESAC, SOCAN (For Canada). I started at $40/Mo and my station usually gets around 30 listeners during the day every day/month. That said your part 15 station probably won’t get more than 20-20 listeners 24/7 for 30 days. So if any Royalties were imposed i’m sure it would be something in the $20 range. I’m also sure or almost anyway that they aren’t gonna take too much care about a station only reaching 1 mile at best to a home Radio. Now in NY, NJ, California yea you’d probably pay $1k/Mo just to reach 5 listeners/Mo @ 4 hrs tops. Greed is greed and reality is reality and they can want on one hand and sh&t in the other and see which one comes out first and I’d bet the latter. The RIAA is a bunch of greedy pigs who themselves are what is killing the music industry not the so called Pirates. They had the chance with Napster to work out a deal that where ads would pay for every Download and yet they still bitched about them. Now its Spotify they say won’t pay enough. Eventually they will die and the artists will have to promote themselves and do their own leg work. There is even an investigation on how much the artists are getting in the first place from all the money that these Internet Radio Stations pay for royalties. Someone at the top is getting super rich. The whole idea of Radio paying Royalties is like the food bank paying royalties to all the manufactures of food for giving food away free. If it wern’t for Radio the John q public would not Buy the music for they would not do the reaserch themselves to know what artists and what albums to buy in the first place. So the RIAA shoots themselves in the foot good going. They have fought for years and got nothing done except to waste the taxpayers money and the courts time with their scare tactics and they’ve not collected on most of the Pirates they accused in the first place. They have bribed dying cancer patients for Downloading a few songs at the cancer hospital (Yes I keep up with this stuff) and then cry Pirate all decade long and what did they actually win since 2003? Absolutely NOTHING. People still Download for FREE, Shoutcast is FULL of stations who Don’t pay Royalties, Youtube has Pirated music up there and axactly what did the get a whole bunch of NOTHING when they could have worked things out with Napster. So no I’m not worried about royalties for my little part 15 station maybe getting 5-10 listeners at best big wooop.
OK now that I’ve finished my Rant about the RIAA back to the Part 15 subject: If we work things out where we can prove that our new field strength won’t interfere with other licensed stations we have a winner. Yes it is gonna take lawyers lots and lots of lawyers and if the other Radio group already has contacts and we join forces with them and present a reasonable petition to the FCC with some safety measures such as Chip in the Antenna to be sue you can’t connect an outside antenna to a transmitter @ 1 Watt and it goes 5-10 miles cuz you have a 100 foot tower or it has to be a Transmitter/Antenna system sold as ONE UNIT the FCC may take a more favorable look at it. Yes we need to have our ducks in a row for the NAB is gonna cry bet on this and don’t forget the land of the greedy we live in. I even had a safeguard for that too. If you try and put the transmitter in a car and move it drops down to -48DBm (what we have now) and won’t go to the new 1 mile field strength. Homework is needed and I’m thinking about everything I can think of to fight of Satan himself. Even a Radio service where the individual hobbyest may have to apply but trying to get a type of service where you tell the FCC the intended frequency, your place of planned transmitter and they will know where you are if any problems arise and tell you “Hey your gonna have to turn it down a bit.” if any interference is found. All in all we need moe True FM lovers to Join forces. If you have blank frequencies in your area we urge you to join us and fight for our rights as Micro Broadcasters. We’re looking at 87.9 but that one may be a flash in the pan but we’re gonna do one thing at a time. I’ve got the first step started Homework and Study. We need to know what we are doing and use science not just because we want something. Science has to be put into this and it has to be something an average person can wrap their head around at the end of the day. I know what a 500mW transmitter can do on a rubber duck at ground floor so I threw in that data to start. We will get there if we all work together. Look the FCC knows these transmitters are out there and it not gonna end soon. They may be afraid FM will end up like CB (or will it)? People are already turning away from Radio as a music source. Well not really because they’re starting to use Pandora, Amazon Prime, Spotify, Rhapsody, Beats Music, Google Play, Mog, Deezer, Rdio I know I forgot a few. So Micro Broadcasting can actually Save On Air Radio not Hurt It!!!
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