As all USA Part 15 FMers know, (or should know...) if we go on anywhere between 88 - 108mhz, we're subject to that ridiculously minuscule field strength limit. We have to try and fight kilowatts with microwatts under Pt. 15.239.
Has anyone here besides me read Pt. 15.236? Please check it out! These rules allow putting an FM "Wireless mike" on the air, between 76 and 88mhz, with NO field strength limit, and a power output of up to 50mw EIRP, INCLUDING 87.7 and 87.9, if there's no channel 6 TV in your area. (Since 95% of channel 6s have moved into UHF, that's a lot of places)
In my area here in Fla., 87.7 and 87.9 are the only two frequencies I can use without being interfered with, or interfering with someone else. I think I've found the answer to my dilemma!
If you're not happy with Pt. 15.239's restrictions, please read Pt. 15.236 and let me know what you think. I'm giving this a shot. I know I'll cover a helluva lot more area than I'm able to do now, legally. Only snag is, it has to be a wireless mike. (Find one with a line level input. It's still a wireless mike, and still legal)
If you're still with me, also check out Pt. 15.203 - Antenna requirements. Here you'll read that you can put an external antenna on your wireless mike...like a ground plane or a dipole, as long as your EIRP does not exceed 50mw. That can give you a MUCH, MUCH better signal than legal operation under 15.239. Any takers?
Hi Mark! Most FM radios (here in the US anyway) are able to tune down to 87.7 or at least 87.9. It's how we used to be able to listen to Channel 6 TV audio on an FM radio. With most of the channel 6 stations moved to UHF, it opens up those two frequencies for our use with wireless microphones under Pt. 15.236. All you need is a wireless mike that will cover those frequencies. The challenge is finding one that will perform within FCC specs. Those Chinese brands are easy to find and buy, but they splatter all over the dial something awful! You can build your own, but that's beyond many of us. I found an old one on Ebay made by Nady systems that works for me....it's even FCC certified for operation between 76 and 88mhz. So they're out there, and it can be done legally in the US according to everything I've read. I don't know about Canada...Best of luck to you!
Seems we went down this road before. Reading 15.236 it's very specific about all but the 76/78 mHz operation.
Previous discussion regarding this made it seem this is for use by broadcast stations only.
Also, it states wireless microphone as described within the rule yet there doesn't seem to be a description given.
Typical, it's specifically vague.
The 76-88mhz band is identified as such in the opening line and title of Pt 15.236. But thereafter, it's referred to as "channels allocated and assigned for the broadcast television service", beginning in item 5 ( "Spectrum Act") (c) (1).
Broadcast stations can get special privileges (assigned frequencies, primary status and more power) on some bands by licensing their wireless mikes, links, etc. via Part 74. Part 15 operating privileges however, are available to any US citizen.
A wireless microphone is very well described in 15.236 (a) Definitions (1). It is quite clear we must use a "wireless mike" to operate under Part 15.236. HOWEVER....Most wireless mikes also have line level input jacks, which makes it possible for us to feed audio into a wireless mike, just as we would do with a transmitter. Just because we choose to use the line input, DOES NOT mean we're not using a wireless mike, NOR does it change the definition of a wireless mike. Yes, we must use wireless mikes when operating under Pt 15.236, but NOWHERE in the rules does it state that we cannot use the mike's line level input.
It's written in typical "legalese", requiring concentrated, repeated readings (not to mention the use of a fine toothed comb...) to finally figure it out. But I believe I have finally done so.
I am not hesitating to make my move from adherence to Pt. 15.239, to 15.236, and will of course keep the group advised on how it's working for me. Thanks for your input!
Some wireless Headphones transmit on 84.950 Mhz @ 50mW as my friend Berry had. Now it is Certified by the FCC.
Some Tecsun, Sangean, and other Radios as well as Radios with TV sound can go there. The FCC rules does not tell you that you can't give out the frequency to other people. I'd give it out on the Deltaville VA Facebook page as well as how to get the right Radio. Its Album Rock for the people.
If you try this let us know if it works and if it can be heard on an FM radio.
I looked this up for the Canadian rules on this and here's what I got....check annex G.....https://www.ic.gc.ca/eic/site/smt-gst.nsf/eng/sf01320.html#aG
It says 50mW also for 76-88.0 under license free use(RSS-210)
So you are trying to use a wireless mic as a transmitter that can be received on an FM radio and playing music and operating it as a station.
Somehow I think there's a catch but first let us know how it works.
Maybe you are on to something, who knows!
Mark - Glad to read that a similar opportunity apparently exists in Canada too! I have 9 FM radios in my home plus one in each car, making a total of 11. They all tune down to 87.9, and all but 3 can also tune in 87.7. (Two at home and 1 in a car will not do 87.7)
My plan is to play music and old radio programs I enjoy from my den into a wireless mike on 87.9, which will transmit to a receiver/amplifier/speaker set-up I have on the far side of my patio on the other side of my house, so I can listen to my music and programs on the patio, without having to run wires all the way out there. A true wireless mike set up. Now if someone in my neighborhood happens to pick up my programming on their radio because my signal happens to go a block or two, Great! As long as I'm not interfering with anyone or anything, am not over 50mw EIRP, and am compliant with Pt. 15.236 in every other way, I'm legal. I have solved my dilemma by being able to use more power on a clear frequency that I cannot do under Pt. 15.239. See you on the air!
As far as I know I don't think the FCC rides around listening to programming on such a device. And I doubt anyone would complain about it unless of course they to have a wireless microphone and they are trying to use it for maybe a musical rehearsal or concert and you're coming in with something that's foul or you're interfering with them when they first went on the air and you came on 2nd.
Another method of broadcasting to an audience which I am also looking into is the fact that the old baby monitors and old intercoms used to broadcast just above 1610 kilohertz. If memory serves me well some of these use carrier current so that would mean it would automatically have the coupler in it. If memory serves me well they didn't have a polarity plug so if you plugged it in one way you actually had neutral injection. The trick would be to find one that broadcast on a frequency that you want say 1630 or 1640 kilohertz. You would have to sacrifice SQL Mayhem stereo in exchange for range and certification but this might be something to look into for my situation in Deltaville Virginia.
I'm also thinking too if I can get the Am side to work well I could advertise the wireless headphone system and frequency. Now I'm wondering about those audio video centers not the digital ones but the analog ones. If we find one that transmits on the frequencies below the FM band they could easily be converted to run on 12 volts like a car battery. 1 to plug it into a cigarette lighter. Now if all the hobby broadcasters were to agree to use ex model video sender receiver and stick to it we could make that particular model a hobby broadcast unit kind of like a gentleman's agreement. Again since there's no rule saying that you cannot give out the frequency I think we might be onto something. Us happy broadcasters have spent way too much time worrying about what we cannot do but there are things we can do is just not blatantly saying that we can if you know what I'm talkin about.
When this was brought up I'm Michelle Bradley's for him and I believe by the same person in which I responded that there's no rule stating I cannot give that frequency out Michelle Bradley did not post anything to argue that point. And we all know that the FCC monitors that forum on a regular basis so as far as I'm concerned from what we're seeing here there's nothing saying by law you can't do it. Now some may think it's immoral to do so but again nothing in the manuals that come with these devices and nothing in the rules state that I cannot give out that frequency. And if they intended it to be private they would have encrypted it with some sort of scrambling mechanism similar to what they started to do on some cordless phones to keep Scanners from receiving it. Now in the future if they start doing that then of course you won't be able to use the newer devices but as a rule of thumb if it's not scrambled it's not your legal to give out that frequency.
The Legacy -- Interesting idea about using an analog "audio visual center" just below the FM broadcast band. But is that a "wireless mike"? If you're going to comply with Pt. 15.236 (the governing part for unlicensed operation on 76 - 88mhz, among other bands) I believe your transmitter has to be a "wireless mike" (or a wireless musical instrument link) by the FCC's definition of same. I'm afraid that requirement may wipe out the audio-video centers as an option. You may want to re-read the portions of 15.236 dealing with this.
ONN branded Wireless Headphones come with that transmitter I described which was certified it has an FCC ID number I don't remember the model number at this point though I was thinking about getting one because evidently it must pass some sort of whitespace device rule.
Musical instrument link is just a elaborate way of saying line in or line input. That line input could be fed to your computer.
I would not think that Walmart would sell an illegal device although I could be wrong but Walmart is one of those highly known places in which is selling this device that people are using as a wireless headphone. In one of the Walmart reviews it talked about someone who lived on a second story near a lake who took their boat out and they could hear that transmission from it's paired transmitter up to the other side of the lake in which he talks about being around a mile. If that's the case there you have it.
Again I doubt so long is the transmitter is certified that the FCC is really going to monitor your content to see rather or not you're playing an electric guitar or singing into the device. And again the wireless headphones was advertised as a way to play your music or audio from your TV to the wireless headphones. So again somehow they were able to use that sort of loophole we're talking about. I would think as long as you're not playing commercials or selling commercials I would think that you would skirt around any legalities with this very same concept.
Interesting discussion, but the idea just doesn't seem fly.. It simply doesn't coincide with the objective of the rule. As always FM is definitely not the route to attempt with part 15, it makes a lot more sense to utilize AM.