FCC part 15.219, then, is for what is called in Canada "anouncement" transmitters(bets-1) which allows the increased field strength here for FM for the applications you mentioned.
What you need in the US is a similar catagory for FM, not just AM.
Mark
From Reply 29: ... Again, if you look at the FCC inspector training manuals (redacted copies are available on Hobbycaster.net) it clearly acknowledges that 15.219 has no field strength requirements.
_________
However §15.219(b) does limit the total length of the antenna, feedline and ground lead to 3 meters.
A review of Part 15 AM NOUOs issued from FCC field inspections shows that if an installation does not meet §15.219(b), then they revert to §15.209 to judge its compliance.
If that inspected system is producing a field intensity at 30 meters greater than permitted by §15.209, THAT becomes the basis for an NOUO, rather than non-compliance with any part(s) of §15.219.
So ultimately, those NOUOs are based on excessive field strength.
Whether or not it was intended by the FCC, it is very easy to exceed the field strength at 30 meters permitted by §15.209 when using a 3-meter, base-loaded, Z-matched antenna system driven by many/most commercial Part 15 AM transmitters.
Part 15 AM users generally have been left to sort this out for themselves.
At times I have wondered if most of you have my posts blocked, because I seldom if at all see reponses to my posts, with the exception of forum member TheLegacy.
I am currently working an a open/usable FM channel survey, I have used the FCC data base to get a list of FM stations that operate within 100 miles of my location.
I block an FM channel in my list if it is located next to a local FM station.
Below is a partial list of what my list looks like: means this is a local station * means blocked channel next to local station's channel.
93.5 *
93.7 WZMX Hartford CT
93.9 *
94.1WHJY Providence RI
94.3 *WYBC New Haven CT ???????
94.5W233AG New London CT - Town Of Monroe 0.055 KW V/H
94.7*WMAS Enfield CT ???????
94.9WJJF Montauk LI New York
95.1 WRKI Norwalk CT ????
95.3 WHFM Southhampton LI NY ?????
95.5 *
95.7WKSS Hartford/Meriden CT
95.9 *
96.1 WSRS Worcester MA
96.3 *
96.5WTIC Harford CT
96.7 *
96.9 WEHN East Hampton NY
Another thing I am working on is using the FCC database to aquire each stations 60 dBu or 40 dBu contour area as an KML file for use in Google Earth. It places a station's contour circle into Google Earth for comparison and I have added all the stations in my area to the map. I can not post images into another persons thread, however, if I could, I'd share with you all what Google Earth looks like with each station's contour circle added to the map and how congested my FM broadcast band is between 88.1 and 107.9MHz.
Long Island New York ties up a lot of potential FM channels that could be used by Connecticut, even some station owners who already own and operate local stations, have placed transmitters on Long Island New York with an unintruding signal reaching Connecticut, because there exists no obstacles because Long Island Sound is all water, no land masses to block the signal. Those transmitters block a lot of potential channels from being used in Connecticut.
Point of my post is realistically, there are NO open channels on FM even for legal part 15 use, operating an IPOD to FM radio device is impossible to use here, because there are no clear channels available to use such devices.
The FCC needs to accept this and realize that both licensed FM band 100 watters (or more) ERP stations and part 15 FM consumer devices can NOT co-exist together!!!!!
I think 87.7 and 87.9MHz is two good options and we need to stop assuming a compliant part 15 device is going to cause that much interference to other services. I do realize USA television channel 6 uses 87.7MHz for the audio carrier, however, channel 6 will operate with a digital audio transmission, where most part 15 devices are analog.
Using 87.9MHz will have a lesser impact on channel 6 or 88.1MHz broadcasts.
Regardless of what we propose, the facts are that the current FM broadcast band in the USA is only 100 channels wide and it is already filled beyond capacity, for the future, the FCC is going to have to come up with a solution to accommodate any future FM broadcast band licensed broadcasters. The current FM broadcast band can no longer accommodate any new licensed broadcasters.
Bruce.
ATSC is too fragile any amount of interference of any kind sends the digital into fits.
simply clear out chanels 5 and 6 expand the fm band, set asside some frequencies exclusively for part 15 devices on the exisiting as well as exppanded fm band. maybe 2 on the expanded, 2 in the educational, 2 in the commercial segment 1 upper 1 lower.
i realize we would need 2 single channel guard bands (1 up 1 down) per a channel.
also at that point up the power to 100uV/m @ 30m and allow the option to use a single antenna (measure at 30m from radiator), multi antenna (measuring at 30m from each radiator), or measure from the property line (private residence, trailer park, stadium, apartment complex, etc)
only realisitc way such a setup would work. and no excuse (other than heavy political lobbying by commercial broadcasters) to not do it. the fcc needs to finally ditch the politics and get back to regulating the airwaves in the public interest!!!
and this translator abuse needs to be addresed and translator licenses rolled back heavily!!!!
leave AM alone, no FM on AM Translators, clean up the band of noise generators starting with IBOC and these cheap china noise making imports!!!!
open up 1710-1780 for 100mW TPO (not to final) broadcasting into whatever antenna system you can dream up and realistically fit in your situation. this will allow for experimentation.
maybe some sort of reasonable licensing, testing and associated fees could be involved similar to GMRS / Ham.
@MrBruce i think the same thing about my posts, they often (more than not) go unanswered, unreplied to.
MrBruce and kc8gpd, most of the time when readers agree with what you say in your posts they will not respond because they have nothing to add.
The two posts above make sense to me and I agree with them.
Im sure if we band together we could open a category in the USA like this for FM.
To my understanding, when the FCC is done with the re-pack of the television broadcast band, they are going to change the format to which the audio and video signal is being to be sent out over the air.
It, to my understanding, is supposed to be less vulnerable to interference, which is why VHF low will once again be a viable piece of spectrum for television broadcasts.
If that is the case, the low level of RF output that a part 15 device produces will have less of an impact on television frequencies. Now compare that power level to licensed stations putting out thousands of watts.
Everyone is correct, we need to help the FCC wake up and realize this is no longer 1953, things need to be updated and re-researched for the current situation the spectrum is in. In 1953, there was very little in the way of FM or television broadcasts.
Look people, lets look at the US Citizens Band (CB radio) as an example.
In the beginning, only 26.965 to 27.255MHz (channel 1 through 23) was authorized for CB radio, then when CB became popular in the late 1970's, the FCC authorized 26.965 to 27.405MHz Channels 1 through channel 40.
Whatever caused them to add those additional channels to the CB band, has to be proposed for the current FM broadcast band for the better of all those concerned, both consumers and licensed broadcasters.
Perhaps we need to speak to our Congressmen?
Bruce.
Since im moving to Deltaville, VA i would not know where to begin. Plus im willing to bet id hear "That is an FCC matter." And worse many officials have lived in a cave when it comes to ANY unlicensed Radio broadcasting. This i$ where we need to educate the masses. We have woork to do.
Ah yes, I was 1 year old then. CB radio started up soon after and as you stated around 1970 the FCC increased the channel count to 40 due to the popularity of the band.
It was still so congested that you could hardly use it to communicate between a base and mobile at legal power levels.
Then cell phones happened, another way to wirelessly communicate. People became less sociable, CB popularity waned and now the band is mostly quiet unless the skip is rolling. There's a few die-hards out there but not that many around here.
So AM was King until FM, with its superior fidelity and noise immunity, took the crown. Then the Internet and WIFI streaming happened along with Smartphones and FM started to sweat, AM is crying for help.
Move the AM's to FM translators because no one is buying into the IBOC. Move FM to Digital and cram more revenue into less spectrum. Expect people to invest money into new equipment and discard their old equipment. All the while Internet and WIFI streaming is gobbling up the audience. It's even part of the newer radios.
Whatever you want-Whenever you want it!
Maybe soon, the AM and FM bands will go the way of CB and we'll have them to ourselves! The masses, not we, will determine what happens next.
In 1979 cell phones we're not very popular. The skip was very intense for CB. Many folks gave it up due to this. The die hards we're mostly the skip shooters who had high gain antennas and powerful linear amplifiers. If you had good money you could afford a powerful CB station. If not you are left in the dust. When the sunspot cycle reached its peak and ended CB was very quiet. I don't see everyone and their brother owning a low powered FM transmitter. If this was 1978 maybe more would be interested.
RF# 26--
..However it probably does explain the origin for the belief (of some) that the FCC permits greater coverage for unlicensed AM systems than it does for unlicensed FM systems.
c5#29 reply:--
Again, if you look at the FCC inspector training manuals (redacted copies are available on Hobbycaster.net) it clearly acknowledges that 15.219 has no field strength requirements.
RF#32 reply--
However §15.219(b) does limit the total length of the antenna, feedline and ground lead to 3 meters.
A review of Part 15 AM NOUOs issued from FCC field inspections shows that if an installation does not meet §15.219(b), then they revert to §15.209 to judge its compliance.
If that inspected system is producing a field intensity at 30 meters greater than permitted by §15.209, THAT becomes the basis for an NOUO, rather than non-compliance with any part(s) of §15.219...
Reply to #32 --True.. But there's nothing peculiar about that. If the install is obviosly not to par with 15.219, then the only alternative is to judge by the feild strenght under 15.209; (as you just stated) and if that's excessive, then it's obviously out of complience.
RF#32--
..So ultimately, those NOUOs are based on excessive field strength.
It's really all in which angle you look at it...
It's just as true to say the NOUOs are ultimately based on improper install, after all , there are no part 15 broadcaster who operates under .209 (it's pointless to do so)
If the 15.219 was in complience, then the feild stregth would have been inconsequential, and there would be no NOUO.
So in reality, the NOUO's are actually based on eccessive ground leads.
But getting back to your original statement:
RF# 26--
..However it probably does explain the origin for the belief (of some) that the FCC permits greater coverage for unlicensed AM systems than it does for unlicensed FM systems.
You insinuate that the FCC does not actually permit greater range in AM than with FM. It's a false insinuation. The "origin of beleif (of some)" as you put it, is unquestionable reality. The FCC does permit it. - Unlicenced AM systems, provide far greater range then FM, because the FCC regulations made it possible by the incorperation of 15.219 into the rules.
So again as I've stated we need to try and get fm on an even playing field for unlicensed broadcasting or a service comparable to New Zealand's for fm. And 87.7 + 87.9 should be allowed in areas where the frequency is clear.
From Reply 41:
Unlicenced AM systems, provide far greater range then FM, because the FCC regulations made it possible by the incorperation of 15.219 into the rules.
That is true. I did not state otherwise, just pointed out the probable origin for it.
For some "calibration" ...
A system fully meeting §15.219 for an average installation might be this:
- 3-meter Vertical Monopole, base at the surface of the earth
- 2.4-meter (8 foot) ground rod buried vertically directly below the monopole
- Earth Conductivity = 5 mS/m, d.c. 13 (average)
- Operating Frequency = 1650 kHz
- Tx Output Power at Loading Coil Input = 50 mW (unmodulated)
- Base Loading Coil R, at System Resonance = 20 ohms
NEC4 analysis shows that this systerm will produce a field of about 3,800 µV/m at a horizontal distance of 30 meters (clear site assumed).
The maximum field for a 1650 kHz system operating under §15.209 is about 14.5 µV/m at 30 meters.
Thanks. This makes my theory invalid.
see...
~c200