Ther'es a blog called Engineering Radio, and it got controversial when it posed the idea that radio engineers should help the pirates to keep clean signals on the air. The idea was, these guys are going to find ways to broadcast anyway, so at least teach them the right way, technically.
I'm not in the market for anything FM, but I like to look at all radio equipment that's available, to see what's out there, you can learn some things. Whether Part 15 or more, it's best to always have a clean signal, and it just takes knowing what the good equipment is, and possibly spending a little more.
I think the Veronica policy of discrete components and common ICs is the way to go. Broadcast Warehouse was good too, they did use some custom programmed chips for their front panel computer entry and display, but were still solid quality stuff. I'm not sure if they do world market transmitters, or just USA Type Approved broadcast FM now, since they've pushed into the LPFM market.
In my opinion, most of what we call the "low priced Chinese junk" is just hack equipment, when put up against anything commercial. It seems to me that the manufacturers put together some circuits around a stereo generator IC intended for mp3 transmitters to play through car radios, and added an RF amp to them, intended to be the cheapest thing possible, and it took off.
It seems they've kept building on to the same circuit, mainly to add more power and better low pass filtering, but it's still the same lowly stereo chip. I'm thinking they didn't expect it to take off as well as it did, and they sell, so there's no reason to improve. About the best thing with those transmitters is the extruded metal cases and the quality of the circuit boards within. Why do some use power wasting LED readouts, have only an option for 50 microseconds pre-emphasis?
I like hobby radio on AM, FM is getting full, and it's taking care of itself, it doesn't seem to need stations to help the band, where AM needs the alternatives, especially in areas with all talk, it could use music. AM has fewer formats, so it's easy to program an alternative.
What a lot of us tend to forget about FM broadcasting is not every two situations is the same.
I see the same reports from people about how FM will work based on other reports.
10 watts or 30 watts at your location is not going to have the same results at my location. Many think it will, based on the posts I see here and elsewhere.
Hills, trees, co-channel, 1st adjacent, buildings, weather, antenna, antenna height, system condition, ground conductivity, all play a major part in the final out-come.
I would like to be able to experiment and be able to post real-time reception results, however, doing so, puts me in a bad spotlight here and if the FCC was to investigate me, trust me, they would use my posts against me as having known better, then to break the rules, but did so anyways, by operating an FM transmitter at 1 watt or above.
Many speak about experimental licenses granted by the FCC, but I highly doubt, I would qualify for such, in overly congested FM band like the one in my area is. I am in a quad-state area, New York, Connecticut, Rhode Island and Massachusetts have signals on the air and some stations from Massachusetts are very powerful, such as WAQY 102.1 FM and WGBH 89.7 FM
The terrain in my area, is like a rollorcoaster, the glaciers that formed New England, really carved out the terrain in my area. Drive two miles and you will have climbed a hill and dropped into a valley, climbed another hill and dropped into another valley. The landscape here, is anything from 2 feet above average terrain to 435 feet according to Google Earth, with most hills at 400 feet or above occupied by a broadcast tower of some type, either FM, AM or television station.
So for the average person, who can not construct a 100 foot or taller tower, because of aviation restrictions and requirement of antenna registration, most would be stuck with a maximum height of 60 feet above the ground level.
Broadcast stations, place the towers on the highest hill and erect towers that have heights of 100 feet to 500 feet and above, giving them a clear shot at the distant horizon, some 20 miles or so into the distance.
You can not compare and assume all things are equal when it comes to FM radio broadcasting, because they are not.
EVERY situation IS different, no matter how much you claim they are the same.
That is why 1 watt is not as dangerous as many assume or claims it is, 1 watt in one area may provide a statifactory signal at 1000 feet, where in other areas, 1 watt, may not be receivable at 100 feet, due to interference issues in that given area caused by the licensed broadcasters.
The LPFM broadcasters, have been finding that out first hand and they are using ERPs of 50 to 100 watts and can't cut the mustard for their intended service area! 1 Watt isn't going to perform any better, in fact, it has MUCH less of a chance of performing at all!
Bruce.
Bruce you have a valid point and this is what I wanted to talk about more in the Elite section of the NRR site because one can’t google you there. In order for us to ask for more power we have to be able to talk FREElY without the fears and judgment of big shots and personal Radio police. I can’t wait till the DAY when Donald Trump gives the FCC the Ax. Reason for so I’m sure the “If they are not interfering let them be.” phrase will be a reality and we can all sleep easy and talk and even get out a few miles without looking over our shoulder. That being said I know good and well that the antenna and the location has a lot to do with your Range so if they were to go by an easy to measure system it should be location based. Or simply “Turn your power up till you get 3 miles to a Car Radio” no stupid FIM beter, no stupid uV/M at whatever distance. Use a Car Radio with a sensitivity of 0.9 uV and be done with it. You can have 7 Watts with a telescopic antenna or 1 Watt with a Comet antenna you get 3 Miles that is IT!!
If your an apartment dweller and they made it legal Today Donald Trump steps up on the podium and says “FCC Your Fired!” and “Hobby Radio Broadcasting is 100% legal on any blank FM or AM frequency as long as you don’t interfere!” I know first and foremost that some of the folks here on this site would RUSH and grab their CZE-7C’s and their STA-501’s (50 Watt Transmitter) and have at it. But I also know not everyone would go buy them. Now I also know that inside the house on a telescopic antenna it takes 7 Watts to do the same as a 1 Watt signal outside your house with the antenna 10 foot above your roof and you’ll only get 1 ¼-2 miles with that sort of set up FULL QUIETING AND STEREO FROM A CAR RADIO and 1 mile to a digital boom box if you have a blank frequency above and below yours. I’ll not reveal anyone I know who done it but lets not contribute to the Big Lie and that is what I call part 15 (sorry my own opinion). Its like cocaine get a tad bit of useless sampling of the drug and you want a little more until you get that high. Part 15 is like that drug dealer who says “Try this” and gives you a few MG’s of pot or coke. Just enough that you get a slight head rush but not enough to get you high for a few hours. 10 minutes later your sober and want more. The FCC (The Pump who controls the drug market) only wants their drug mules to be successful so they make ridiculous laws to stomp out the competition. Now back to what Bruce was talking about.
Even 250 uV/M will give different results in different locations sorry it will. Some have to try and run 50 watts and still not get out as far as what a 7 Watt signal through a telescopic antenna (In the house) mind you will do I’ve seen this in many reports elsewhere. I’ve heard reports like “I’ve got a 50 Watt transmitter connected to a Comet antenna or ground plane and I only get 2 miles and sometimes struggle to get 3 (What that can be done with a 7 Watt transmitter with a telescopic antenna) but in their area they may have hills, 10,000 trees between them and the receiver all attenuating the signal. I’ve seen a 300 mW transmitter connected to a 5 Ft piece of thin wire inside the house get 1 mile (What???). Again sorry but how can we learn if we can’t even talk about this stuff. If this gets deleted you know where you can talk freely about this and I feel it needs to be talked about just a bit. The FCC knows you don’t pay $15,000 to go 150 feet and if you think they believe that I have an Ocean front property an Arizona I’d like to offer you and those who are real nice I’ll throw the golden gate in for FREE.
Again I’m sorry I let this stuff get to me but I think sometimes we need that reality check to keep us together as a Hobby Broadcaster. Now we can go back to our regularly scheduled talk about part 15:239, the sins of long ground radials, ect.
To bring this thread back on the original topic, Mr. Bill of Hobbybroadcaster has many opinions. This one is just plain condescending.
People do Part 15 broadcasting for different reasons. Everything from transmitter/antenna experimentation, sending music around the house or yard to full radio station businesses (although there really aren't many of the latter).
All are valid, and we can all learn from each other (yes, even Mr. Bill), without putting anyone or anything down.
And yes, it would be nice to have some sort of community license available to those who are really serious broadcasters. But there's far more to running a business, even a small community radio station, than just buying a more powerful transmitter.
... Again I’m sorry I let this stuff get to me but I think sometimes we need that reality check to keep us together as a Hobby Broadcaster. ...
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The reality check for Part 15 FM that appears to be misunderstood by the author of Reply 18 of this thread is that FCC §15.239 limits the field intensity 3 meters away from its transmit antenna to 250 µV/m for good reason.
Namely, that then the FCC can predict the peak interference levels from such unlicensed setups that are, or may become objectionable within the normal and authorized coverage areas of present _and future_ licensed users of the FM broadcast band.
That is one of the mandates and functions of the FCC.
The operators/proponents of unlicensed FM broadcast setups who decide on their own, and publically promote that such systems should be (or are) permitted if they don't interfere with licensed FM stations at a given time/location can sabotage this process.
Please keep this thread on-topic (the programming of Part 15 systems).
People are always welcome to start new threads to discuss other topics (including field strengths, potential range, interference issues, etc.) of Part 15 systems, as long as they stay within the rules of the Forum.
The thread is about Part 15 AM & FM being pretty much useless except for in-home broadcasting. And, that is why I bought the Veronica.
It was my way of protesting. But yeah, FM is OUT as far as any Community Radio goes. An apartment dweller like I am...even AM is not easy, unless I want to broadcast to the tenants like I am now. There is nowhere to put an antenna outside.
So, we settle for inside. There goes your range.
Ya know, Community Radio CAN be done, and within legal limts! The SSTRAN and Spitfire are made to work with a loaded coil antenna. That damn Ground Lead Rule keeps the antenna ground-mounted, though.
Since 1500 is clear up here at night, I would crank the power to whatever level I need to maintain the same coverage I have during the day (Damn the rules). But I can't do that. It takes more equipment than I have or can afford. But, if I was serious, and much more than a hobbiest...
I figure 1 - 5 watts would cover downtown at night, here. That Greek 10 watter...this one:
That would do the trick. Crank it back to 1 watt (or five if that's what it takes) for night broadcasting.
See, I just want to cover downtown and that's all. The TH 5.0 did that nicely. Not at night though. This begs the question: why have a Low Power station at night? Night traffic downtown is almost non-existent!
Doug
Part 15 AM is not useless, unless you're doing it wrong. A functionally compliant setup can still achieve miles of coverage.
This completely ignoring the fact part 15 was never intended for broadcast. Fully agreed that FM is completely useless, which was the intention. The average joe should never have access to higher power levels because there is no way to gurantee he understands RF fundamentals. There is a reason why high-powered stations are issued licenses. I suspect the bulk of FM's restrictions comes from its proximity to the Aircraft band.
Or cannot set it up to be fully functional. I ain't done yet. Frustrated yes.
"This completely ignoring the fact part 15 was never intended for broadcast..."
Good point. We kinda did that. Glad we did too. I say "we", LOL. I had nothing to do with it! Ha!
Doug
In college when I studied Radio we had to describe the definition of “Broadcasting”. Broadcasting according to Jim Greene professor at Lansing Community Collage was “to reach an audience without discrimination.” This mean ANYONE who has a receiver within range CAN receive our signal. In other words your signal is not “Scrambled” such as HBO, IT Subscription TV, SececTV or XM Radio where it is intended for an audience to “Pay” for the content you air.
So in essence part 15 AM/FM is “Broadcasting” otherwise why not send a signal on 900Mhz with an Audio/Video sender and then connect your Receiver to your portable speaker when you go outside? We all know that when we spend $$ and good $$ on a Wheatsone mixers, Compressor/limiters and modulation monitors we are kidding ourselves when we make ridicules claims that we don’t intend to “Broadcast”. This has been discussed at both Lansing Community Collage and Olivet Community Collage when I took upon myself to volunteer for a summer to work at WOCR in Olivet Community Collage.
Lansing Community Collage had a part 15 FM station called WLCC which later became a “Licensed” FM station. That station got out 800 Ft outside the campus with a car Radio.
One student made a stupid comment that we were not really broadcasting since the signal got only 800-1000 ft off campus on a good day. Jim Greene was MAD and said “If that is what you think you can leave my classroom NOW!” and proceed to tell us that so long as we have an audience that can hear your station you have a responsibility to have professionalism on air.
Stewart Blacklaw of Olivet also had a similar attitude when it came to low power broadcasting as I have kicked around the idea of starting up an AM station when I was there which would cover my neighborhood and maybe up to John Henrey printing company which was not even a mile from my house in Lansing Michigan at the time. Stewart Blacklaw tried to convince my Mom to buy the old part 15 AM transmitter they were in no need for so I could learn at home and actually broadcast. Mom asked how far it went and he said about 2 miles if they set the antenna up outside. He would even help to set it up but Mom thought Radio was silly and refused to buy it for me even though she had the $500 as Dad wanted to buy it for me and set up an appointment for the install.
I’ve learned a lot and wish I had got that AM setup because I’d had learned how to install an AM transmitter “Right” and learned how to broadcast Album Rock on AM as Stewart insisted I could and even get listeners. It was a chance I could have had to learn not only FM but AM too.
Now by watching that youtube video I’m learning how AM could have been an advantage for me as there would be no fence posting and with lessor power get out the range that many operators try and do on FM. Somehow I think before too long my Landlord will come up with something as she thinks what I do is good and keeps me out of trouble so she said. This comes from an older woman.
Of course we use Part 15 to "broadcast", I'm talking from a regulatory standpoint it wasn't intended to be used that way. At the time these rules were made 900mhz wasn't used for anything and no consumer gear existed that operated there. However, everybody had an AM or FM radio. The rules were written mostly with the thought in mind we'd use it much like the 900mhz (or more common 2.4ghz) AV sending devices are used today; Short range hops to nearby recievers.
We essentially lucked because the characteristics of the medium wave band allow low power levels to reach long distances. Plus the gear has gotten better and more efficient, gotta love Part 15 AM! Though I'd call us microcasters since the coverage area isn't very broad. All that said, I agree that we don't spend what we do just to reach our backyards, thankfully AM makes it possible.
I'd say, Legacy, you make a very convincing point. For me, serious Part 15 has been useless for me. Every time I get it going, I get shut down. Time before last, it was because I had to move. Then the TH4.0 died, and now the TH5.0...
See, I have run 10,000 watt Collins and 5000 watt Gates and Harris AM transmitters. You warm up the filaments for ten minutes, and when you hit the high voltage button, it sounds like a shotgun! Scary. My friend listened to me on WZON AM 620 from Bangor, Maine to Boston on a road trip!
So, ya see, Part 15 is a whole 'nuther world here. I'm retired. 61. Need stuff to do (gum, gum)...can't see much. But hearing one's voice on AM...makes it worth it.
Doug