by MRAM 1500 kHz
We're all drawn to this broadcasting thing. I'm a ham radio operator and I have worked the world on ham radio. So why is this broadcasting thing so addictive?
Everybody here seems to have such great technical information and help with interpreting the rules. But ya know, you can be compliant in every respect; big systems that limit field strength to 15.209, little systems that satisfy 15.219 blowing away a 15.209 and yet, all the FCC has to say is 15.5c and you are done. So, why do they come out?
by MRAM 1500 kHz
We're all drawn to this broadcasting thing. I'm a ham radio operator and I have worked the world on ham radio. So why is this broadcasting thing so addictive?
Everybody here seems to have such great technical information and help with interpreting the rules. But ya know, you can be compliant in every respect; big systems that limit field strength to 15.209, little systems that satisfy 15.219 blowing away a 15.209 and yet, all the FCC has to say is 15.5c and you are done. So, why do they come out?
Granted, there are appliance operators that don't know how to avoid causing interference but it sounds like most everybody here is technically competent enough to avoid that.
So, you met all the technical requirements but someone heard your station and got upset. And it doesn’t matter if the signal went 2 miles or only 200 feet. The complaint must have been “interference” as there is no limit put on coverage. They only suggest 200 feet as being realistic given their design limitations.
Let's get a roster going of people who have actually been shut down or at least visited by the FCC. I'd like to hear first hand why they came out, if they explain that. And oh, were you by the book or maybe pushin’ it a little bit?
Try Phelgm's FCC Enforcement Database
www.diymedia.net/fccwatch/ead.htm
His home page, obviously,
www.diymedia.net
Hello all,
No, I have never been visited or busted. I thought you might be interested in how I operate.
I began part 15 AM activity in 1959 when I went on the air with a KnightKit AM broadcaster with a 10 foot antenna (legal then...now 3 meters). I used this rig constantly through 1967.
Later, I used the Knight on and off until 1998 until I upgraded to a Ramsey AM25 and now a SSTRAN AMT-3000.
Here are my governing principles:
1. Keep the physical antenna, ground, transmission lines to the legal limit.
2. Keep the power to the legal limit for AM.
3. Limit the audio bandwidth to 5 kHz. on AM and 15 kHz. on FM. On AM I mainly transmit talk radio and on FM I transmit music.
4. Operate on a vacant daytime frequency at least 20 kHz. away from an occupied frequency.
5. Keep the material clean. I transmit music only on FM without my comments since I already know them and I am the only listener that I know of.
6. On FM, I use a Ramsey FM 25 with an antenna cut so it covers my property and can be heard about 200 feet away with a car radio. I hear it about 75 feet away with my Sony Walkman which meets my needs.
7. I consider part 15 AM and FM rules to allow personal use and limit the range of both transmitters so they cover my humble 1/2 acre estate and not much more.
8. Keep a low profile. I do not tell my neighbors that I am on the air since I don't intend for them to receive my signal.
I am not saying that broadcasting to your neighbors is not legal nor do I discourage anyone from doing so. I am just telling you how I operate and I have had no problems with part 15 operation for 47 years.
Neil
I would have to agree with swis. Just research past stations that have been busted and use your personal judgement.
Honestly, the FCC isn't interested in breaking in doors and slamming people to the floor. They will write you a letter first stating to resolve the interferrence, then if there is no resonse, they will issue an order requiring you to resolve the interferrence and pay money, then if there is no response, they bust in your door and slam you to the floor 🙂
If you make a valid effort to keep your station legal, you have NOTHING to fear, just have fun!
Most of the articles I read involving the FCC raiding a potential violator location and carting away the equipment has been for egregious long term violators who have "basically" stuck their finger in the FCC's eye. We call them "pirate" radio stations. They run from several watts to hundreds of watts output and really don't care if they interfere with anyone else or not. Their "life's record player needle" is stuck on the free speech and emergency service aspect of community radio.
Most end up violating Section 302 of the Communications Act of 1934. Simply said the federal government has been charged with regulating and preserving the radio airwaves as a "public trust".
And as such, these violators have no leg to stand on with free speech and emergency service with an unlicensed station.
Part 15 of the regs in concert with the rest of CFR 47 allows for the opportunity to freely express ones inner angst. And without procuring a license from the FCC.
The significant flies in the ointment, are the contradictory and in consistent rules which for all intents and purpose were written for garage door openers and wireless microphones. Community oriented low power broadcasting was never even in the back of the regulators minds when Part 15 was dreamed up. Most of the rules were a knee-jerk reaction to the quickly expanding development of "intentional" radiators including everything from garage door openers to wireless phones, WiFi routers to digital sampling systems. Part 15 low power broadcasting was thrown in there for grins and giggles because of the public outcry due to limited access to the public airways without a substantial monetary investment and the help of attorneys.
Low power FM has been an administrative nightmare and became reality when a small group of congressmen and senators got involved and threatened the FCC with a change in their funding.
My opinion is that Part 15 broadcasters need and deserve their own regulatory section. A section specifically dealing with the technical and public service issues facing the users of this service. A section supplying an even-handed approach to "legal" low power broadcasting. And at the same time, offering all parties with an interest in the public airways a realistic opportunity for legal redress without thousands of dollars in attorney's fees.
Specific realistic regs concerning measureable power levels, signal strength, signal purity, equipment certification, antenna design and service area without attorneys or expensive laboratory grade test equipment.
Implement these measures and watch the number of raids and violations decrease substantially. There will always be the crazy's who just don't get it and will maintain their right to operate their "pirate" radio facilities. The FCC could save time and money with these simple steps. Maybe with Michael Powell out the way and new members of the commission, we as Part 15 broadcasters can bring pressure to bear on Congress to make some regulatory changes. In the face of the natural disasters over the past few years, community radio stations have once again come to the front burner.
What do you think?
It will take an act of Congress to make changes for the better in broadcasting Part 15, but don't hold your breath anytime soon...
If we agree, then its time to mobilize those who have consensus on the issues of concern. Get a list of the congressmen and senators who serve on the committees who can get this done and start writing letters and sending emails. And don't stop until there is a definitive answer.
It took an act of Congress to for lpfm to become a reality. Lots of emails and letters went to Washington, D.C. to get what we have. Are people willing to do whatever it takes to encourage positive change? It will probably take an act of Congress to get lpam as well. If Part 15 broadcasters were to get together and form an informed consensus of what rules and regs we really need, and communicate those to policy makers as proposed rulemaking, you might be surprised by the outcome.
Are Part 15 broadcasters willing to educate policy makers that they aren't "pirate" radio stations? Should they be informed as to the service these radio operations provide to the citizens of this country? Or, do we continue to be lost in the fog of public policy perception?
Marshall Johnson, Sr.
Rhema Radio - The Word In Worship
http://www.rhemaradio.org
by MRAM 1500 kHz
Well, the point of the original post was to dispell the rumor that the FCC regularly harasses Part 15 AM stations. Either no one is going to fess up about being visited, or it just rarely happens. I suppose for those that worry about it, they must be doin' something to worry about.
I still feel that for the majority of the visits, interference is not the problem as most stories end with " the FCC saw my certified transmitter and left without shutting me down."
If they visited because of an interference complaint it wouldn't matter if you were legal or not. You would be shut down, 15.5...
So apparently in those cases, someone heard a station and didn't like it for one reason or another and wanted it shut down when there was no interference. Of course, broadcast obscene or indecent material or run outrageous power and you've got problems regardless. Otherwise, if your lean and clean, the FCC has better things to do.
mram1500, I keep an eye on the FCC website that shows letter citations issued to violators and have never seen one issued to low power AM, and that includes those in excess of 100 MW. Those issued to individuals are for FM, shortwave, CB, etc. The others are to licensed radio/TV stations, cable companies, etc. Jim B
RE:
http://www.fcc.gov/eb/FieldNotices/2003/DOC-261747A1.html
"The field strength of the signal on frequency 1700 kHz was measured at 27,000µV/m at 35 meters, which exceeded the maximum permitted level of 14.118 microvolts per meter (µV/m) at 30 meters for non-licensed devices operating on frequencies between 490 kHz and 1705 kHz."
27,000 uV/m??? I make that to be almost two thousand times the permitted emmissions, or basically something like a 1000 watt station.
Duh!
Quote=scwis: 27,000 uV/m??? I make that to be almost two thousand times the permitted emmissions, or basically something like a 1000 watt station. Duh!
_________________
That is WAY less than a 1,000 watt commercial broadcast station on 1,700 kHz -- it has about 9 volts/per meter, 35 meters away from a 1/4-wave vertical radiator.
A legal Part 15 AM system using a good 3-m radiator at ground level (complying with 15.219) can produce a field strength much above the 15.209 limit. One analysis I've done shows more than 100 µV/m one mile away.
Cranking the numbers in this citation shows that a radiated power of about 9 nW from a 3-m vertical will produce a groundwave field of around 27,000 µV/m at a radius of 35 meters. So apparently this operator wasn't doing anything not permitted by 15.219.
I wonder why this citation was issued.
The citation sez:
"measured at 27,000µV/m at 35 meters, which exceeded the maximum permitted level of 14.118 microvolts per meter (µV/m) at 30 meters"
27,000 micro volts per meter at 35 meters vs 14.11 microvolts per meter at 30 meters appears to be the reason for the citation.
So, if the station was cited for emissions, can we guess that the station was not using the alternate stantard of a 3 meter radiator and 100 mW dc input?
I'm also having a bit of trouble connecting this to the impression I got from some of your earlier posts about it being impossible for a Part 15 transmitter using the stantard of a 3 meter radiator and 100 mW dc input to be received at distance because the emissions aren't strong enough.
So the emmisons are not strong enough... yet also too strong... I'm just so damn confused...
Quote:
"Cranking the numbers in this citation shows that a radiated power of about 9 nW from a 3-m vertical will produce a groundwave field of around 27,000 µV/m at a radius of 35 meters. So apparently this operator wasn't doing anything not permitted by 15.219."
There is no way... a 100mw Am transmitter would do this at 27,000uV/m at 35 meters....
I calculated that this person was using 20 watts and probably was using a TIS/HAR transmitter with anywhere between 20-30 watts of power depending on the gain of the antenna....
You are right to believe there is some suspicion with the quote above.
9nw is not the 100mw the FCC defines as the Part15 power for AM and this amount of RF would go no further than the room the transmitter would be in!
Quote=scwis: I'm also having a bit of trouble connecting this to the impression I got from some of your earlier posts about it being impossible for a Part 15 transmitter using the stantard of a 3 meter radiator and 100 mW dc input to be received at distance because the emissions aren't strong enough.
My previous posts haven't stated that it was impossible for a Part 15 AM with 100 mW input power and 3-m radiator at ground level "to be received at distance." Here is one on this topic I posted on Radio-Info on 12-31-05. I think I posted them on Part15.us, too, but this archive was easier to find and use.
These distances and fields apply to a legal Part 15 under 15.219, but they would not be legal under 15.209.
+ + +
Below are some "benchmark" values for the field strength at several distances from the r-f system described there.
These calculations are based first on a NEC-2 analysis to determine the FCC efficiency for the antenna, and then using that value with the FCC's propagation curves for the frequency and ground conductivity, to determine the distances. This is a proven process which applies even at these low powers.
This information should assist anyone wanting to know the coverage performance of an excellent Part 15 AM r-f system, as described.
DATA:
Frequency = 1700 kHz
Applied Power = 80 milliwatts (~output power of Part 15 AM tx)
Radiator = 3-meter total length including the conducting path from the tx chassis to the ground plane (antenna is ground-mounted)
Antenna System RF Resistance, Loading Coil plus Ground = 10 ohms
Ground Conductivity = 8.0 mS/m (typical value)
Radiation System FCC Efficiency = 21.12 mV/m at 1 mile for 1 kW applied
RESULTS:
Field Strength > Distance
2 mV/m > 0.09 miles (good signal)
1 mV/m > 0.18 miles (fair)
0.5 mV/m > 0.34 miles (noisy)
0.05 mV/m > 2.5 miles (very noisy)
//
continued here: http://part15.us/node/683