well, i was just passing this by word of mouth for the last week or so, but we are need more members who can add more coherent discussion to the topic(s).
Suppose the FCC responded to various "Initiatives" they received to increase the radiated power for unlicensed transmit systems in the MW broadcast band to the same as they permit now for TIS stations under §90.242.
That TIS radiated power produces a field of 2 mV/m at a distance of 1.5 km (0.93 miles), which is about 20 times greater than an unlicensed system compliant with §15.219 can produce at the high end of the broadcast band (1610 - 1700 kHz).
In order for a 2 mV/m field to have the 26 dB protection from co-channel interference that the FCC defines for some classes of AM broadcast stations, nighttime interference to it could not exceed 0.1 mV/m.
Now suppose I was able to install an FCC-authorized, unlicensed station on 1670 kHz able to generate a 2 mV/m field 0.93 miles from my location in Illinois. The broadcast station on 1670 kHz nearest to me is WOZN in Madison, WI (10 kW day, 1 kW night). That is a GW path distance of about 240 miles.
Daytime interference from WOZN would not be a problem, as their daytime GW field here is about 2.5 µV/m. But their 50% nighttime skywave is about 0.155 mV/m, which is only 22 dB below 2 mV/m. So the coverage area of my unlicensed station having a 26 dB protection ratio would be quite a bit less, due to WOZN.
Just some of the considerations than may be useful in planning for a new class of service in the AM broadcast band.
and that is one of the reasons we need you over there rich. we need someone to help us hammer out many issues we may not even be aware of.
i also made a motion to place this higher power service in the 1720-1780 band and extend part 15.219 to 1710 and 520.
i haven't seen any feedback on that motion yet or my suggestion we elect a chair person.
There are many licensed AM broadcast stations with many thousands of people in their day/night interference-free coverage areas, but having so few listeners that they are barely surviving. In some cases they have quit operating, and surrendered their licenses back to the FCC.
This shows that even having an interference-free signal over a large coverage area certainly is no guarantee of success.
Part 15.219 already includes 520 kHz as a usable Part 15 frequency, in fact the specified range is 510 - 1705 kHz.
But the Carrier Current Rule, 15.221, only specifies 525 - 1705 kHz, and it would be reasonable to request including 520 kHz as a usable frequency by matching the allowed range of 15.219 (510 - 1705 kHz).
Seeking to bring 1710 kHz under the 15.219 umbrella makes obvious sense for the convenient reason that 1710 is part of the frequency band available on modern radios, and wherever you go there appears to be nothing happening on the frequency. It's already allowed under the much lower power range permitted under 15.223, so we're talking about a small power increase for 1710 to match with 15.219.
The matter of seeking higher than 15.219 power levels in the AM band is right now up for discussion, and will be more difficult to pin down.
The range 1720 - 1780 kHz is already allowed at very low power per 15.223, so here again the Petition is considering a power increase for this region. How high an increase? Remains to be seen.
the part 15 resource library is open now. you need to be registered and logged in to access it. everything is hosted on dropbox, so you may not be able to access it from a corporate network.
"the part 15 resource library is open now. ..."
Kindly inform us: What titles/subjects does it contain, and who authored the papers in this library?
JHC Rich. Do you just sit with your pants pulled down to your ankles waiting to pounce. Several people on the site including RECNET's Michelle Bradley have posted some comments about what is real and what is not. You were invited to the site to share your engineering experiences. Don't be a Dick.
there are white papers, manuals, schematics, ebooks, etc from all over the web. some scanned by me, some by others.
If either petition achieves more range for almost any band it will become swarmed by religious nut-bags who want to recite from their patch-work book of old folktales and hearsay and we'll miss these old days.
i have actually been thinking about that a lot as of late.
i have been pondering if any petition for more power on any band is a good idea.
i do think about the aspect of the potential for any new service to be over run with religious zealots.
one of the things that needs to be discussed about with regards to the petition.
they over ran LPFM and are the prime abuser of translator filings which block potential LPFM's.
wdcx asks: Do you just sit with your pants pulled down to your ankles waiting to pounce. Several people on the site including RECNET's Michelle Bradley have posted some comments about what is real and what is not. You were invited to the site to share your engineering experiences. Don't be a Dick.
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Mr Mouw: As cordial and enticing as you phrased your post (clip above), somehow it does not persuade me to contribute my engineering experiences to "the site."
Not knowing the context of why Rich asking about a library is seen as inflammatory, just looking at the face of it as seen on this page, Rich's response comes across as pretty funny and the right way to play it. 🙂
Things aren't always as they seem.
The context is that Rich WAS asked nicely to help (I know, because I did it) but he obviously declined to do so, which is his right (it's too bad, though, because his input would have been valuable). If he had become involved, he would not have had to ask the question, which I (as well as wdcx obviously) saw as rather nit picking.
Okay, that does make sense.