http://groups.yahoo.com/group/LPAM
http://groups.yahoo.com/group/LPAM
This group is for the discussion of the proposed commerical licensed Low Powered AM broadcast service that is presently before the FCC at this time. Supporter input needed so that better ideas can be implemented and incorporated into the proposal. The proposal calls for LPAM stations to operate at 30 to 100 watts, operate into 50 foot tall antennas and operate on the upper end of the AM broadcast band from 1620 khz to 1700 khz and that the service be of a commerical nature which would allow LPAM stations to be owned and licensed by ANYONE.
This will not be a place to hash out legal setups for part 15 operations as www.part15.us is setup for that purpose.
Thanks for the info.
Thanks for posting us about this proposed LPAM service. I appreciate it and will join the yahoo group. Maybe this will become a reality and also help many who need more power to transmit ( rural areas, poor soil conductivity, etc)
Have a great day!!!
Travis
LPAM proposal
Well, I suppose this is the proper place to bring up my concern.
If, as proposed and described in the first post in this thread, LPAM is allowed with the power levels mentioned I ask where that is going to leave the lowly part 15 AM folks. Some of the best frequencies for our use exist in the 1600 to 1700 kHz. band and it appears that these will become filled with licensed LPAM’s.
With at least one AM station going dark in my area and general terrestial broadcast audience decreasing it is hard to imagine that these stations will fill the void that some think exists in broadcasting.
If LPAM does come to pass, say goodbye to unlicensed AM because you will not find a vacant frequency to play with. There will be, as I mentioned a few moons ago, a “food fight” over available frequencies among the prospective licensees and politics will prevail in the assignment of licenses. Once again I predict the little guy will be excluded.
Neil
What would become of part15
I tend to agree with Neil, at least somewhat.
Thinking through what would be likely to be in any final version of a licensed LPAM the FCC would adopt, I think part15 AM as it exists now would likely be over.
Firstly, broadcast band licenses are pretty much always to serve the public over a specific area. So licenses are station licenses, not licenses for individuals who might change address. Like LPFM, it would require owning the property the station is on or having a long-term lease secured.
Secondly, the FCC tends to favor organizations over individuals for broadcast stations because organizations tend to be more stable and more able to actually keep a station going consistently once it’s started. It doesn’t serve a purpose to assign a frequency and then have the person lose interest and have it tied up until the license expires. That’s why churches and not-for-profit orgs got most of the LPFM frequencies.
Then the gear, like current LPFM, would pretty much have to be commercial. No more homebrew or kits or tinkering with units. Probably the antennas as well. May also need to have an actual engineer in at least occassionally. So that would move the price range right out of some people’s budget.
So I think the possibility of it being owned and licensed by “anyone” would run into some problems.
Another point would be the 50 ft antenna height. Maybe out in clear country, but most cities/towns (which offer the best chance of a good sized potential listening audience) have at least some air traffic. So more likely it’d be the old 20 ft above the roof without special permission and marking lights. probably less if you’re close to an airport.
Then there’s having it be “commercial”. From a regulatory point of view, it’s a whole lot easier to keep tabs on a large station, say 20k watts (or whatever is typical currently for standard licensed AM stations) than to try and watch over a whole herd of little stations that will only manage to cover maybe the same amount of geographical area. They went “non commercial” for LPFM I think so it would fill the community radio and public service sort of need. I think it likely that they’d consider a commercial LPAM service to be competition and a lot of complaints from the regularly licensed AM commercial stations. Why should they allow it when there’s already an existing license structure for commercial stations on the AM BCB?
Ok, but that’s all just my thoughts on the idea itself as you’ve explained it here. Now, concerns I’d have about how it would affect part15 AM as we know it today..
Back in the late 70s, the college station I was at lost it’s license. There had been some issues with station admin not keeping proper logs, and it was a little 10 watt FM class D which was a service they were phasing out at the time. Even then there were rumors of a low power FM license class in the works for schools and community organizations. The rumors sounded a *lot* like LPFM finally actually ended up. But around the same time, part15 FM went from being allowed 100 milliwatts to considerably less.
Now, there may have been many reasons for that, but consider this one. Worst case scenario, if you have a licensed 30 watt station, it likely will have a range of at least a few miles. But if someone sets up an unlicensed part15 in maybe your fringe range (lets say it’s not intentional interference, they just weren’t careful about finding a clear local frequency), if they can get a range of a mile or two with a really good xmitter and antenna, that’s a heck of a bite out of that 30 watter’s potential listening audience. Not a big bite out of a 20k watter’s, but an awfully big one out of your few miles. So you and/or your listeners complain, the FCC has to come out, track it down, and tell them to shut it down or move to a new frequency. A major enforcement hassle in these days of tight budgets in the gov.
My theory is that at least part of the reason part15 FM was cut back to it’s modern tiny range was so it wouldn’t interfere with the anticipated LPFM stations. If the same thing happens with part15 AM, it’d be so many microvolts at 3 meters, not 100 milliwatts into the final rf with a combined length of 3 meters for antenna, feedline, and groundwire (if used). It’d be easier to just cut it back to “house radio” range like that, than to deal with all the enforcement hassles needed to protect the LPAM licensed stations.
The FM dial had a lot of space in many places before LPFM. But the frequencies got gobbled up fast, and in some cases sit idle because they were licensed but then people didn’t carry through on getting the LPFM station going. I’ve read through some of the things about starting an LPFM (at least when a window for filing is open), with talk of looking for ‘derelict or abandoned’ not-for-profit orgs that can be taken over, getting together with other orgs and agreeing to share a frequency to squeeze out others who might be applying for it, and having a budget planned in the tens of thousands of dollars and some good lawyers if you’re serious about doing LPFM. A lot of politics and powergames in some cases, at least.
That’s a long way from a hobbyist buying or building a part15 compliant transmitter and building an antenna out of parts from the local Home Depot and going on the air on a freqeuncy that checks clean. Someone who is doing it just for the love of it and perhaps for the experimentation and learning involved.
Personally, I doubt that the actual eventual reality of a licensed LPAM would be as pretty as what you propose, and it *could* be the end of part15 AM as it exists now.
I rather doubt I could manage to get an LPAM as you describe going even if the proposal stayed pretty close to what you describe and was only changed a bit to make it work by the FCC. It’d likely end up at least a lot like LPFM has, so far as regulations and who actually gets licenses. I took a good long hard look at LPFM, and for me personally, part15 AM would be more practical for having a small hobby station on the BC bands. That’s why I’m here and asking questions and reading posts.
But I do not mean to speak badly of your dream, and I hope I haven’t been too discouraging. It’s your dream and you have to chase it. But I’ll stick to my own dream. I wish you well, though.
Daniel
Maybe there could be some way to compromise.
The supporters of LPAM could also make another proposal. To keep from gobbling up the upper AM broadcast band they could propose for a minium amount of distance between the LPAM’s, such as not more than one LP within 50 miles or so. If that was done, there would be possibly less competition for x-band frequencies.
Travis
Skywave question
While the 100 millwatts and short radiator with part15 AM make it highly unlikely for a part15 signal to hit the ionosphere and “skip” long distances..
Would 30-300 watts with a longer radiator be more likely to do so and as such for stations licensed at that level to add to the night-time congestion on the AM bands or interfere with dx listeners of stations licensed at the higher standard commercial power levels?
Daniel
Skip
Daniel,
Yes it is possible to achieve long distances via skywave propagation even with low power. Hams do this frequently with what is called QRP though they have the advantage of being frequency agile and can select a quiet frequency to use.
Any signal can follow any path which is “open” for propagation. The thing that makes it “readable” is the signal to noise ratio (S/N) at the receiver. It is very unlikely that a 100 mW. signal will produce enough signal to noise ratio at a great distance to be copied because of the noise. Some experimenters are doing this over hundreds of miles with very narrow band modulation which gives an advantage in S/N ratio but it is certainly not the norm.
Higher power (as you mentioned 30 to 300 watts) will increase the S/N ratio and will have a greater potential to be heard or to cause interference due to “skip” propagation.
I think the future situation regarding AM DXing is going to be dominated by interference from groundwave signals if these proposed LPAM stations proliferate as FM and FM translators have. There will be few frequencies in metro areas which will not be covered by the ground wave patterns.
AM DX is almost dead already. Some of the stations which I would listen to on a table radio at night in the early 60’s can no longer be heard interference free here with an outdoor antenna.
I just checked the frequency of our local TIS station which is, I presume, running 10 watts and is located two miles from me. It is hard to copy due to the noise from nightime skip from other stations. This is certainly going to be a factor in the LPAM stations’ night operations.
Neil
There may be a way to solve that problem
What the FCC could do to prevent massive skywave is make some of the LP’s reduce power at night. Make the 100 watter’s cut down to say 30 w, and the daytime 30 watter’s could stay the same. That could possibly ease some of the problems between part 15 & LPAM. Travis
LPAM interference
Hi Travis,
You are right. But don’t you think all these conditions and restrictions are leading right back to what we have now on the AM bands?
You may agree or not, but I think what is lost on many is that even with 10 watt or so LPAM there will always be those who wanted to be licensed who were excluded.
The physical fact is that there is only so much spectrum space available and some will get their piece of it and some won’t based on who knows what.
I have seen this happen with amateur radio repeater coordination and have no reason to believe LPAM or LPFM will be any different. It could even be more vicious if money is involved.
You seem like a pretty bright fellow who is thinking about this so maybe you can solve the problems I forsee.
Neil
You do have a good point, Neil
You are right about the licensing issue, Neil. There would be some who would get their own piece of the pie, and unfortunately others with only a bare dessert plate. In some cases, the need for Licensed LPAM would diminish if the 100mw limit was loosened to 1-3 watts. If restrictions were not as strict with part 15 AM, there would possibly not as many in need for Licensed LPAM. As for now, this has renewed my love for part 15 AM. In fact, after church tomorrow, I just might go to the drawing board and try to figure out how to improve my SSTRAN’s range. I appreciate your comments about this. I’m fixing to call it a night. it’s currently 11:53 PM Central and my eyes are blurring to the point that I can hardly read the Computer Screen.Travis
A thought on Travis’s point
What might work better than loosening the part15 reg to allow 1-3 watts would be if the FCC could have a special permit that could be applied for when someone can definitely show things like poor soil conductivity or an underserved area or rural distance. If it was a permit that was both for the operator *and* the site, they could require logs and a certain amount of community issues programming and perhaps a simple test on part15 technical and general radio know how.
For that matter, they could just limit applicants to people with perhaps a general class Amateur license and require having a current copy of the part15 regs and not bother with making up a test. I’d think that a general class Ham would know enough tech for them to feel more comfortable with them having a bit more privilege allowed for part 15 on the AM BCB?
If they didn’t want to actually allow more power (because then why even think of it as related to part15?) if they allowed something like say, a 3 meter antenna with 1.5 meter radials allowed on the top hat and a 20 ft tower with elevated ground radials coming down at a good angle to bring down the radiation pattern, it might do more for actual range than allowing more rf final amp power. And it could do it without any increase in the chance of additional RF making it into skywave since all the radiation would be confined to a locally useful angle.
Keep it to the current part15 rule of “may not cause interference, must accept any interference from licensed services, no guarantee of an operating frequency and must cease operation or change operating frequency if interference occurs” and etc so there’s no increased problems for the licensed commercial broadcast services and the already existing highway information stations and etc.
The difference would be it would eliminate any debated ‘grey area’ regarding antenna/ground/capacative top hat systems totally by making such measures perfectly allowable if you go the extra bit and get (or already have) a ham license and demonstrate a need for the permit. Maybe have an inspection before the system allowed by the permit goes on the air to make sure it actually complies with the requirements.
In the early days of radio, I believe a lot of the early broadcast stations were started by hams. I know at least one of our still existent local AM stations was. Maybe they’d put it under the amateur section of the rules as a “special operating privilege” that general class can apply for a permit for, rather than part15.
Now, it *might* include a little extra wattage. But that would have to be calculated first to figure out how much could be put into the more efficient antenna the permit would allow and still have a negligible chance of adding to the skywave with the possibility of interference with distant stations rather than an arbitrary amount like 1-3 watts. In an actually adverse location though, allowing an operator with demonstrated technical knowlege some antenna height and a somewhat more effective antenna/ground system might make more difference than upping 100 milliwatts to a full watt would, though.
It could serve several purposes. First, it could get currently underserved (at least on the AM BCB) areas back on the air with information and programming of interest to the local community. It might attract hams (who already demonstrated a certain level of technical and regulation radio knowlege by passing their exams) to come down onto the AM BCB and start little community broadcast stations and develop antenna and transmitter designs that are possibly better. It could encourage part15 operators who aren’t currently licensed amateurs to go for the exam and get an amateur license, which (beyond the small AM broadcast permit they want) would increase the number of hams on the air who have countless times shown the usefulness of amateur radio operations in emergencies and disasters.
I know it would put boning up for a ham license on my “to do” list. LOL
Probably just a “pipe dream”, but hey, as long as we’re thinking outside the box a bit and making wish lists, may as well consider possibilities that would use existing exam and license structures and already existing trained amateur personel and their experience. They’re a “known entity” to the FCC while most part15 operators are not.
Daniel
Its all about the money!!!
The biggest problem with ANY expansion which allows for commercial operations will have the broadcasters,NAB and all screaming bloody murder that we will be competition for them. Not a bad thing,but we are grossly out-lobbied and out-spent and have no chance of fighting that group and winning. More power to ya!
And yes,hams did start the first broadcasting stations. Their reward was to get booted off and those privelages yanked as soon as the Feds discovered it could make money! Regards,Lee,N3APP
As a means of reviving the
As a means of reviving the somewhat moribund AM band, I think an LPAM service would be a good idea. Such a service, although limited to one watt, has been successfully in operation for some 8 years in Great Britain and shown to be of great value to the locals.
http://www.ofcom.org.uk/radio/
What I object to in the proposal is limiting the service to the expanded band. Where I live, TRS stations are littered all over the X-band making it impossible to start a new service. However, there are channels lower down the band that are open and could work. As it stands, most of these channels fall under certain FCC class restrictions. But given the low wattages involved, perhaps these restrictions could be lifted for LPAM use.
If prudently adminstered I don’t see why LPAM and part-15 couldn’t peacfully co-exist.
c5
There is a significant
There is a significant difference between 1 Watt ERP and 1 Watt TX power!
I did some tests (in the Netherlands) with 1 Watt TX power and a 30 feet antenna,no radials only one earthpoint. You’ll be suprised by the coverage I had.
Rob Veld