Aside from misuse of such devices, whether it be broadcasting non-licensed music or intentionally misusing it to broadcast at greater lengths than the rules allow, if the vast majority of the users are those who have already made every attempt at their disposal to operate under the current rules without venturing over the limit intentionally, then there stands to be a chance that the interference issues could be avoided.
Like I said, I am not an engineer and I do not possess the education or knowledge to put numbers into answers related to the math invloved.
But there are those out there who have that education and understands what it means or how to crunch those numbers into answers.
I feel I am too old to start a new career, specially becoming a broadcast engineer and specializing in combating interference issues.
I do understand that the broadcast stations are spaced part both geographically and frequency wise to avoid interfering with each other, however, look at the amount of RF they throw out there into the airwaves.
Sure, a compliant part 15 device is going to interfer with in house reception or maybe even your next door neighbor, but would the FCC really shut you down when only one person is effected and lives 10 feet away from your house? I mean sure, the agent can decide what he wants, but would they travel to investigate when only one person complains?
Doing tests at 1 watt and using, say a spectrum analyzer, to look at the wave form emitted by a given transmitter, we should be able to see the emissions that are causing spikes elsewhere in the band or spectrum. Once we've located a potential spike, a filter can be designed to block or prevent that spike.
Granted, how can we determine where those spikes will turn up, because frequency has a lot to do with where those spikes will show up. This is why part 15 FM should be allocated to a set number of channels that are not used for part 73 broadcast stations.
Lets take FM for example, allow part 15 the use of 87.9MHz or 87.5MHz and design a filter at the output stage that blocks everything above 88.1MHz and evrything below 87.3MHz.
Am I right to say that Ham radio equipment has some type of out of band filtering to prevent interferece to other non-related radio services?
CB radio had a 54MHz notch filter and that was for legal 4 watts into the final, a filter would certainly help prevent interference to the bands that would be most effected by part 15 devices as well.
I know about the arguments that there are so many devices out there that have different degrees of filtering to none at all, but if we do not make some attempt to bring change in the way we use such devices, then we can only blame ourselves for not even trying.
I have said it before, if a company manufacturers a popular transmitter whether it be AM or FM and they charge $100 more for a spectrally clean transmitter, I'd be willing to spend the $100 extra for that transmitter.
I just hope that the rest of the world can follow suit. Perhaps, when we can prove we can own and operate a clean transmitter and NOT cause interference, perhaps, those engineers might someday speak about part 15 radio in a possitive way. Because their biggest fears are interference to their licensed client's signal.
Also as a side note, yes, I am sure their second complaint is loss of listeners to you, but is that really your fault or theirs?
Yeah I'm a dreamer, but dreams can come true if you believe in them and have faith in them as well.
Bruce.
Here is a plot of the fields radiated by a Part 15 AM setup strictly compliant with FCC §15.219, as described.
It can be seen that such fields are strong enough out to a distance of 1610 meters (1 mile) to interfere with licensed AM broadcast stations at, and even within their protected 0.5 mV/m contours.
It would be unlikely for the FCC to permit unlicensed AM stations to produce more interference to the 0.5 mV/m contours of those licensed stations than licensed stations can, themselves. That interference limit is 0.025 mV/m, or 25 µV/m.
Rich is most of that interference considered co-channel interference, 1st adjacent or in band intermod?
If the part 15 AM radio service was placed in a piece of spectrum not directly in competition with licensed stations, would it be less likelyhood of causing interference to them?
By the way, I do appreciate your participation here, perhaps I just might learn something before I enter that big broadcast station in the sky.
Bruce.
... is most of that interference considered co-channel interference, 1st adjacent or in band intermod? ...
The protections referred to are for co-channel interference.
Interference to 1st- and 2nd-adjacent channel stations also is possible even by compliant Part 15 AM stations, but their permitted field level is greater than for co-channel interference, in that the receiver can reject some of that off-channel interference.
ok folks following the chain of events for what happened in 1972 we learned a few things. 1 The petitioner was denied because he was a pirate. Next the petitioner did not show documentation of the range and lack of interference that the higher power levels he requested would cause. Okay this is where we have to thank outside the box. The FCC wants proof right? Proof is what we shall give them. How do we do this you may ask? Simple. I'm sure that certification would have to take place in countries such as New Zealand in the same way the United States would require lab tests or field tests to show proper engineering and the fact that these Transmitters will not cause harmful interference. Now you might ask what does that have to do with us? Well has anyone gave it a second thought to email companies such as ding ding ding Ramsey? you could tell them that you are a part of an FM initiative group wanting more power for hobby radio in the United States and that as part of your petition you want to show proof of how 1 Watt coming out of the antenna for hobby broadcasting will not cause harmful interference to a commercial or LPFM station when careful practice is Used to ensure the operator is far enough from an adjacent channel. This means finding out how far 1 watt will bleed the FM dial from the Transmitter. now doing my homework and talking to Johny C we know that it will only bleed a radio for around 20 feet. However this must be in writing. Remember that Ramsay makes a 1 watt Transmitter for export. Plus they make an amplifier. That in mind I'm sure there were some tests that were made to show performance and lack of harmonics and spurs. These tests are what we need. Get the proper documentation and you're on your way to clearing the road for more power on fm it can be done it just takes somebody who has the drive and the initiative to push forward and ask these companies if they will at least send you that type of documentation. Since Ramsey is getting out of the transmitter kit business they might send you that documentation on good faith. Then the next phase and that is to prove to the FCC how allowing specific frequencies for hobby broadcasting will help alleviate the need or desire for pirate radio. Again countries such as New Zealand can be your best place to start. How did allowing hobby radio in these countries alleviate the pirate radio issue? Next what can hobby Radio do for the community? And can it provide emergency communications? The answer is yes because Micro broadcasting Transmitters are portable meaning they could be set up on a moment's notice. License broadcasters on the other hand have to be certified even if they were to move 1000 feet from the transmitter site. However as long as you have a clear frequency a hobby broadcaster can set up shop and informed community of a natural disaster and where to go for safety. Probably broadcast stations are cost effective in comparison with larger commercial stations. One could set up a computer mixing board or simply a computer and relay circuit are what we need. Get the proper documentation and you're on your way to clearing the road for more power on FM it can be done it just takes somebody who has the drive and the initiative to push Ford and ask these companies if they will at least send you that type of documentation. Since Ramsey is getting out of the transmitter kit business they might send you that documentation on good Faith. Then the next phase and that is too prove to the FCC how allowing specific frequencies for Hobby broadcasting will help alleviate the need or desire for part radio. Again countries such as new Zealand can be your best place to start. How did allowing hobby radio and these countries alleviate the pirate radio issue? Next what can hobby radio do for the community? And can it provide emergency Communications? The answer is yes because Micro broadcasting transmitters are portable meaning they could be set up on a moment notice. License broadcaster son the other hand have to be certified even if they were to move 1000 feet from the transmitter site. However is long as you have a clear frequency a hobby broadcaster can sit up shop and inform a community of a natural disaster and we're to go for safety. Probably broadcast stations are costs effective in comparison with larger commercial stations. One could set up a computer mixing board or simply a computer and realize circuit between the output of the computer and the audio input of the transmitter in the relay box you would have your computer plug into one and and your weather radio. local authorities can use the transmitter for announcements. All is not doom and gloom for hobby radio. just because it failed in 1972 does not mean it has to fail now. take lemons and make lemonade from it learn from the mistakes of others so that they are not repeated again. I still believe we could have a chance in rural areas for 87.7 and 87.9 megahertz. these are two frequencies. Possibly one TV channel. now 4 a.m. there are countries that allow a lot or more for how they broadcasting on AM. there is plenty more in store for the initiative. Too much to go into right now.
The link in the opening post of this thread referred to a 1972 FCC action about an unlicensed AM station, not an unlicensed FM station.
It is unclear as to how that FCC action can be connected to an "FM initiative."
OK it can in the fact that when you don't do your homework and spout off numbers at the drop of a hat just because you want it and think it is going to help your station get an audience is not good enough for the FCC. What they are asking is for the hobby broadcaster who is petitioning for more power to document the result of that level if granted. Where did the hobby broadcaster who made such a petition come up with the figure he or she is asking for. If you can't prove what your asking for is only going to travel a certain distance and not cause chaos to the spectrum than why should they even consider it without a few chuckles before throwing it right in the trash can? Also our FM Initiative is now LW, AM, SW, FM Initiative. Reason for so is Alan Weiner, and some others suggested why stop at FM? Even if we don't get the FM, we may get AM which really doesn't need that much more. Maybe simply abolish the 3 meter ground rule and keep the 100 mW if we don't get the power increase. But getting to the principle of the reason the 1972 petition failed and why we need our ducks in a row or be laughed at and denied. This takes homework, careful wording, and proper formatting to make it stick. Already we have those who are trying to make us look bad. Right down to calling one of our members a Pirate without being an inspector themselves. Too many folks want to put a kibosh on this or any initiative. It only makes us want to do it even more in spite. But one thing is for sure, calling the FCC names in a petition is not the way to do it as I've seen others do. They want actual facts which again are there for the taking and the presenting. In 1972 there was no Internet, but Today we have the tools to try and obtain the proper proof it takes to ask professionally for a power increase for Hobby Broadcasting.
gotta say it again.. I really think this inititive is a pipe dream.. There's no way you'll ever be granted more power (expecially not a watt or two as I think you previously said!) to transmit further distances and not be required to obtain a license for it. It's simply not reasonable, nor feasable! There's enough problems with the airwaves as it is.. What you are essential suggesting is to make the problem even worse.
What you keep pressing about has nothing to do with Part 15 at all.
If you want enough power for your broadcast signal to reach greater masses on the public airwaves, the only legal option you have, or will ever have, would involve going thru the proccesses and expenses and other hoops required to obtain the license to do it.
Part 15 is free, what you're wanting is not, nor can it be.
I was going to say, I really don't think Legacy knows how the FCC works... At all.
And not a knock at you Legacy, I'm glad you are so passionate about your cause.
That being said, Lab testing doesn't mean jack when you're talking about real world interference.
I'm going to have to side with RP on this one, never going to happen. Too many variables between operators is another problem all together.
FWIW, proper FCC procedure would be exactly how the big boys are licensed; A site by site basis complete with professional engineering, coordination, frequency study, ect. Enjoy footing that $1,000+ invoice.
The engineering cost to include Construction Permit and License application for our LPFM was $800. That included a waiver to obtain the frequency.
Why pick a frequency that required a waiver? That pretty much guaranteed we would have exclusive use of the frequency as most LPFM applicants would not want to go through the process.
Otherwise there may have been contention between more than one applicant which may result in a time sharred frequency situation.
In addition, the firm we worked with supplied an equipment list. This was convenient when it came time to make equipment choices.
My rule of thumb for getting a date with a woman that was way above my class was to think that unless I got a rejection I would never really know.
Same thing with The Initiative. We don't stand a chance of getting it, but we won't be rejected until we get that official turn down complete with an FCC Seal.
Better to have tried, and been rejected, than never tried at all, even if you know you'll be rejected.
Mark
Ok no rant from me.
Just trying to be open minded here and not steer off track.
I am 100% pro here, I'd like to see a change.
I am open to arguments and do not get offended if you all disagree with me, beause, being closed minded gets me and you no where.
My personal opinion and it is my personal opinion, is that we are bringing too many requests to the table at one time and might very well get an instant dismissal on the whole petition.
A case and point that I have been following for some time now, has nothing to do with part 15 at all, it has to do with the LPFM radio service that asked for both more RF power output, increased antenna HATT and the right to play paid for hire 30 to 90 second over the air commercial spots.
I am sitting here and trying to decide how much information I should provide to this topic which has nothing to do with LPFM and the LPFM-AG petition for change, because it really steers off the topic and scope of this topic I am currently posting to.
Long story short, reading all the published documents and the petition on line, I really felt, the person or persons who drew up the petition and the on line comments made by those who were pro and con, I seen many mistakes made by those who started the petition in the first place.
One major issue I seen, was attacks made on those who opposed the idea, rather than responses that remained civilized and professional sounding. Even if you do not agree with opposing views to your cause, you can not respond with attacks or assults on those people.
Short and to the point, the petition granted more RF power, but correct me if I am wrong, but wasn't the right to play commercials (besides under writing) on LPFM stations denied?
Sometimes asking for too much at the same time, can come across as wanting your cake and eating it to.
My personal opinion is asking for SW/AM/FM at increased power output at the antenna for part 15 broadcasting might be asking for too much at the same time.
First off, you DO NOT want to ask for 1 watt at the antenna!!!!!! Not for SW not for AM and not for FM.
At the very most, you want to ask for 1 watt into the transmitter's FINAL OUTPUT STAGE, that request could very well fail to pass, but it is better than asking for 1 watt at the antenna. 1 watt out at the transmission antenna is a lot of power.
I realize, the hardest part is having every transmitter on the air complying with all the rules and that every operator is doing their part to go above and beyond to make sure they operate their equipment in a manner that does not cause harmful interference to other radio services.
That is the part that has to be worked out and let's face it, that is not going to be easy. It starts off with finding and purchasing transmitters that have passed strict testing to show that all attempts have been made to limit the potential for off channel interference.
Co-channel can not be avoided obviously, so therefore, if need be, accept the restriction of being asked NOT to operate on a frequency that is within your local market area. I can not say for sure if 1st adjacent or 2nd adjacent stations can be effected by your device, the possiblity is certainly there, it is best to avoid using a channel that is anywhere close to your local market area stations, right from the start. Stay 4 channels away from them even if you are on the AM broadcast band.
Rather than everyone just sitting there saying NO IT'S NOT GOING TO HAPPEN!!!!!!
Think positive, you just might be wrong, look at marijuana legalization for example, in the 1970's there was attempts made to decriminalize marijuana, it failed and marjuana was looked at as the demon weed.
Look at the nation today, many states have legalized marijuana for medical purposes, now many states are legalizing it for recreational use. But many said IT WILL NEVER HAPPEN!!
Look at gay marriages, many who were gay, never thought they could some day marry one another, now they can. But some said IT WILL NEVER HAPPEN!!!
Look at the first black president of the USA, some said THAT WILL NEVER HAPPEN!!!
No this has not happened yet, but if Hillary Clinton is elected president in 2016, she will be the USA's first woman president and Bill will be the first "First Man" After that happens, I am sure today, many say, THAT WILL NOT HAPPEN!!!
It is okay to dream, sometimes, dreams do come true.
Instead of being a nay sayer and caving into the brain-washing, let's talk about why you feel so negative, perhaps your views can be changed if you look at the light from the same angle as others see it.
History has shown, time and time again, if things are done right and everyone is on the same page together, change is possible. It may not be to everyone's liking or approval, but anything is better than nothing. Just be careful as to how many things you ask for all at once, sometimes, greedy sounding requests can be denied, so limit what you ask for and it might be seen as a resonable request.
Keep the faith and stand together.
United we stand, divided we fall.
Bruce.
I agree with Bruce.
I think it should be common sense to follow standard FCC spacing rules.
Edit: On A Side note Bruce, I'd be surprised if a lot of folks realized quite a bit of the power is lost before it ever hits the antenna.