It's one thing to use Part 15 to broadcast to yourself, i.e., you are the primary listener. One can argue that the Part 15 rules were designed for that specific purpose. But it's quite another to attempt to attract an audience - that's an entirely different beast. Canada distinguishes between those with RSS210 (broadcast to yourself) and BETS (broadcast to others).
The needs of those two functions are entirely different.
Artisian said:
It's one thing to use Part 15 to broadcast to yourself, i.e., you are the primary listener. One can argue that the Part 15 rules were designed for that specific purpose. But it's quite another to attempt to attract an audience - that's an entirely different beast. Canada distinguishes between those with RSS210 (broadcast to yourself) and BETS (broadcast to others).
The needs of those two functions are entirely different.
Well Canada may distiguise between the two, but in the U.S part 15 only distiguises between intentional and unintentional broadcasting (it wasn't always so, distinction went in the rules in the 1970s I think). Furthermore the Part15 rules specifically state that it doesn't matter what, how, or where or who to the broadcast is intended for - So I totlally disagree that "..One can argue that the Part 15 rules were designed for that specific purpose.."
Also - As I've stated many times, the biggest group of Part15AM broadcasters is and have always been Parks and Recreation, the whole purpose of which is to attract and broadcast to an audience.. So I don't know how your formulating the idea that Part15 is actually intended to broadcast to yourself.
Perhaps there is some Hobby Confusion
Well, you'd have to go back to the architects of the intentional aspects of the Part 15 rules to get the real scoop as to why they were created. But I stand by my statement that they probably weren't intended for general purpose broadcasting to a large audience. The old statements (which are still sometimes dragged out) that BOTH AM and FM ranges were 200 feet attests to that. Of course, you can get much more range on AM than that 200 feet with a decent installation - even the FCC recognizes that, and changes the enforcement procedures to dial range back in to I guess what they consider to be reasonable levels.
My breaking down intentional Part 15 into broadcasting to yourself and to others was not predicated on the rules, but how most of us use them. Some want an audience, some don't. And if you're broadcasting to yourself, you don't require nearly the equipment or expertise than if you are attempting to emulate the 'big boys'.
I suspect that most of us broadcast primarily to ourselves in any event, regardless of wishes.
Perhaps Canada is ahead of the game in breaking down unlicensed intentional transmitting into broadcasting (BETS) and non broadcasting (RSS210). What seems at first to be confusing ends up, when you consider what people are doing, to be reasonably clear.
Ok, the actual reason part 15 was created in 1938 was because the Philco Electronics company had invented a remote control for tuning a home radio from up to 75 feet away..
"..because of its resemblance to a conventional transmitter and receiver, questions arose concerning the legality of the device. After considerable debate pro and con and a hearing or two, the FCC finally handed down rules covering the subject..." -QST magazine April 1942 (I previously posted about this in Thanks Philco for Part 15 Broadcasting).
But part 15 has evolved greatly since then. It was late 1960's when Part 15 outdoor installs for public broadcasting began and immeadiatly spread wildly, and has continued to expand since.
I agree that the originally intentions had nothing to do with public broadcasting to an audience, but that is clearly what [15.219] primary purpose has been for the last 40 years.
When you say broadcasting to yourself "is how most of us use them" - I guess you mean hobbyist (not sure that I agree), but most 15.219 use in general has always been for public consumption.
One other thing as long as I'm rambling.. It is related..
The fact is - unquestionably - that the FCC's concern is not really the length of the ground lead - although that is what they use to cite when neccessary, but the real concern is range.. This is why parks and historic sites, etc. never receive NOUOs, it's because they always keep their range in check; in most cases within a half mile.
That's probally also the reason Atlantic Records went for years mounted high on billboards and so forth - it was because they kept their range within 1/2 mile.
The talking house was certified to operate with an entire buildings wire system as a ground lead!.. but as long as the range is kept in check there seldom will be any problem. The ground lead is a farce rule. Range is what will get you shut down.
Of course the whole point is controlling range. But the ground lead rule is NOT a "farce rule". By controling ground lead and antenna length the FCC is controlling range. You can legally have a ground lead as long as you want it, 10 feet, 100 feet, 100 miles, if you should so desire. In which case your transmitter would not meet 15.219, and you would have to meet the 15.209 rule for field strength. Since most people aren't equipped to test accurately for field strength, 15.219 covers that with antenna and ground length limitations, obviously, specifically to control range.
The grround lead/antenna length rule exists as an alternative to the fieid strength limits. On AM if you meet .219 you don't have to care about your field strength. So build 'em high, 'build 'em long, ground 'em all you want -- just be sure to turn the power down so you meed the .209 field strength rule then.
It's not a farce rule, it's an alternative option. You're right that the FCC won't go around measuring ground leads as an enforcement method, but they WILL check out a station with exceptional range, and often that range is obtained with a long ground lead.
If your field strength on AM is legal the size of your antenna and ground lead makes no difference. If your field strength is over the .209 limits but you meet the 100mw input and antenna/ground lead rules, you're legal under that rule.
Worth noting: Part 15 FM has NO such alternative option. Firld strength measured at 3 meters is the ONLY way to determine legal operation. Many have wished they'd come up with a simple and inexpensive way to determine legality of a Part 15 FM transmitter, but this has yet to happen.
TIB
Tim, when I say it is a farce rule, what I mean by that is that it's only selectively enforced. In reality they could care less how long the ground lead is, it's just something for an agent to point too so they can quiet a station.
Again: case in point; For the last 40 years all Park and Recreation Part 15 installs have always and still do utilize at least 10 to 15 feet (or more) of ground lead - None have ever been cited, none have ever been shut down. They operate under the exact same Part 15 rules we all do, there is no written clause or exceptions for them - the FCC has just always turned a blind eye to it.
The FCC has also been known to turn a blind eye to many private individual installs which break the 3 meter rule as well.. why? because it's not the actual issue of concern. I say it's range, but range can be legally extended with multiple transmitters, and it's actually more than that anyway, it's also the content - no, the rules do not place limitation on content.. but in reality, that too is a deciding factor. Range and content.
A part 15 polka station; not likely to ever have a problem. Jazz not likely to have a problem. Broadcasting the mating habits of crocodiles or migration periods of geese in an area; no problem. Community news and event information, no problem.
But if your station is top 40, or country or whatever format which more strongly competes with the licensed stations common formats.. Well if you're getting any range then it's only a matter of time before your station gets cited.
Part 15.209, 15.219, and 15.221 are there to protected licensed broadcasters -that is it's only purpose. And the FCC has said many times in many ways that even if your part 15 station conforms to the rules by 100% you may still be shut down:
"...Moreover, regardless of strict adherence to the technical limitations in Part 15, a Low Power Communication Device is permitted to operate on a sufferance basis only.." - https://apps.fcc.gov/edocs_public/attachmatch/FCC-74-87A1.pdf
Worth noting:
Part 15 AM, the 15.219 option was equal to 15.209. When transistors began replacing tubes it only then made 15.219 more capable of range.. The only reason the FCC didn't eliminate 15.219 at that time was because it was becoming of great value to Parks and Recreation and the general public loved it. - That is the only reason 15.219 still exist today.
Part 15 FM will never be granted such an option; The part 15 AM option created too much of an conundrum already.
Yes, it says even if you are meeting the technical standards for part 15 you can be told to stop but only if you are interfering with a licensed station...not playing the same thing as a commercial station in the area is.
This is a given that we have known all the time. Canada's the same.
One of the reasons that Part 15 radio might be fading (and I'm still not convinced of that - I'm not sure that it ever really shone) is that most are just so gosh darned fractious. Look at the talk that this topic has generated just on the rules alone. Never mind the competing websites, with bans on the sharing of information.
For the proper licensing fee, I may be amenable to cloning my DNA. However you may be disappointed in the complete product!
What Artisan said is how I feel about a lot of things. I've done some kind of home broadcasting since I was a kid, mostly legal but a couple times, not so much. I worked in broadcasting since around 1978 or so both on air and in engineering. What the FCC has allowed to happen in radio (and pretty much anything else) is a disgrace IMO. I've always ran my stations in a legal manner since the time I entered broadcasting. I love taking radio gear on it's way to the dumpster and diverting it to my trunk instead. I've made some of the oldest, most basic gear play clean and loud, putting the commercial broadcasters in my market to shame.
On the matter of transmitters, I've had everything from Gates exciters to my present 100mW eBay FM and I built my AM from plans I modified from an antique radio repair forum. I don't run illegally long antennas, illegal power, and do my best that I can ro make sure my modulation is within spec. I do it mainly because I love radio, but I detest what broadcasting has become since TCA96. I left radio officially in 1998 because consolidation was destroying my career even that soon. Perhaps I'll return once companies like iHate have to sell statiions back to local owners, because I refuse to do corporate McRadio. "Would you like a nine minute stopset with that 200 song playlist??"
I'd really like for someone, ANYONE in the FCC or Congress to address the flea-power levels of Part15, to at least enough to cover a small villiage. One watt in the extended band or something.
FM is wasted already. Where there aren't translators short-spacing everything on the dial, there will be soon. I find it kind of funny that they don't want to expand the terrestrial radio bands, citing obsoleting receivers, yet they expected the entire country to have to replace perfectly good NTSC TV's and gear for their lousy digital plan. If they plan on a sundown for analog radio, there's going to be obsolete receivers anyway, no?
We the People NEED a viable Part15 service as there is hardly anything on the dial that's worth tuning into anymore. As far as news, both sides are spinning everything into a "he did it first, so it's okay that we do it now, too" mentality. Nobody gets the real facts without an agenda. I, also, am a moderate progressive who beilves that the 99% are suffering because the rich want it that way. Part 15 may be the only true voices out there. I hope that we can keep on going as a hobby, even better, a community service, even if we do need to learn electronics to do so. It's probably better that way, since too may "plug-n-play" types who have no idea what a modulation peak even is, would be polluting the airwaves.
I've just procured my first Optimod, for a 100mW FM. Why? Because I'm right under an airport approach and I don't want to overdeviate and splatter onto aircraft frequencies. I think most "plug-n-play" operators would never even consider doing that. Someone who has at least a basic understanding of radio theory would.
I see a lot of valid discussion on the rules. I think, since Congress and the FCC *did* implement LPFM licensing, perhaps the argument could be made for a LPAM service which supercedes Part 15. We have a valid reason, which is that the majority of commercial stations around today fail to actually serve their COL's. Most are not providing anything except background noise from some rack in a transmitter shack somewhere. True, there are some good Part 90 local broadcasters, but they are a very finite minority.
The people deserve better than some voicetracked garbage from five states away, who can't even fake localism right. My favorite? The 27 station Top of Hour ID, played out at 3x speed, mispronouncing seven of the city names. Yeah, THAT is real quality radio, I'll say.
We don't have to re-invent the wheel. It would seem that the easiest solution would be to simply get the AMT-5000 circuit board duplicated and then obtain all the individual parts, which are all still readably available. It was already designed to be a kit that is easily solderable. Perhaps PhilB could grant someone in the group permission or work out a deal to have the circuit board duplicated. Perhaps fiverr.com may have someone offering circuit board duplication on the cheap. You don't even need the outer box if you are mounting outdoors. One of the outdoor utility boxes sold by Summitsource.com accomodates the AMT-5000 circuit board perfectly with four brass standoffs. You can caulk it for total weatherproofing. My tests show that the AMT-5000 has more range with the in-line, home-brewed external loading coil and pipe antenna than with the internal torroid and wire antenna, but I think the instructions to build that will still be on the SSTran site for some time to come. If I had the time, I would look into doing this with Phil's permission. But my schedule is already way too complex and extreme. Nevertheless, it should be done.
Surface mounted part.
U5 is surface mount.