Part 15 AM/FM transmitter

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icbrkr

Part 15 AM/FM transmitter

Post by icbrkr »

Here's a question for you coming out of left field (or the woods if you're at my house). Ever thought of getting into low powered AM/FM transmission for your podcast?

Part 15 of the FCC rules [http://transition.fcc.gov/mb/audio/lowpwr.html] (you know, the one that says your device must receive harmful interference but you're not allowed to cause any) allows for the transmission of up to 100mW on the AM Radio band (provided it's an open frequency) and I forget what sort of low wattage on FM. This is also done without a license. But for sake of simplicity, a 100mW transmitter would run about $100 and you could theoretically cover an area max under ideal conditions of about 1-2 miles. Doesn't sound like much, but look on a map of what is in that range and there's probably more people than you'd think.

Some good information on it can be found here:

http://lowpowerradio.blogspot.com/

and you may be able to convince other LPB to rebroadcast your podcast:

http://www.hobbybroadcaster.net/directory.html

I'm going to be building one and pairing it with some software (http://macinmind.com/?area=app&app=radiologik&pg=info) and trying it out at some point.
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Flack
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Re: Part 15 AM/FM transmitter

Post by Flack »

If you tell me how to tell other people to turn into it and what time you'll be broadcasting it (see where I said you and not me, hah) I will mention the info on the next podcast. :)
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ubikuberalles

Re: Part 15 AM/FM transmitter

Post by ubikuberalles »

Set up the radio at the next OVGE and either give a live report of the show or play a recording of a podcast.
icbrkr

Re: Part 15 AM/FM transmitter

Post by icbrkr »

Charles has a good idea actually. How they receive it? Well, it would be on the AM dial somewhere, and you'd have to be 1-2 miles from the transmitter. Unless you have a huge following that's hanging about my neighborhood, I don't see that happening ;) But my plans at some point are to make some sort of radio station for the fun of it and I'd use you as programming.

My point was to see if you can get other part 15'ers to do the same and have em carry your podcast.
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dstone
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Re: Part 15 AM/FM transmitter

Post by dstone »

I picked up a cheap FM transmitter from some dude in Hong Kong on eBay, use it for one of those dancing light setups. I could bring that to OVGE if you want to tinker a bit. Shoot, they've got some 15W transmitters on eBay, but I'm sure some wonderful people from the government would pay you a visit. :shock:

I've been tempted a few times now to try out some live video streaming from OVGE, although it always seems like I'm scrambling to get things together at the last minute. Shoot, I was at least, what, two hours late to last year's show?

Might be kind of fun to do some sort of radio/IPTV simulcast or something.
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Flack
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Re: Part 15 AM/FM transmitter

Post by Flack »

I see a theme for a table developing ...
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ubikuberalles

Re: Part 15 AM/FM transmitter

Post by ubikuberalles »

If you want a bunch of part 15 transmitters to broadcast the same stuff, you could use a web server as a central hub. The web site would stream audio and the transmitter - connected to a computer on the Internet - would broadcast whatever is coming out of the web site. Theoretically, people with AM receivers across the country could hear the broadcast (providing, of course, there are enough part 15 transmitters distributed across the country).

Or do the opposite: make the transmitter portable with a mic and someone could walk around OVGE reporting on what he sees. A receiver, connected to a computer, could then broadcast what's spoken to the web via streaming.
icbrkr

Re: Part 15 AM/FM transmitter

Post by icbrkr »

ubikuberalles wrote:If you want a bunch of part 15 transmitters to broadcast the same stuff, you could use a web server as a central hub. The web site would stream audio and the transmitter - connected to a computer on the Internet - would broadcast whatever is coming out of the web site. Theoretically, people with AM receivers across the country could hear the broadcast (providing, of course, there are enough part 15 transmitters distributed across the country)."


That right there is what I was getting at. They have directories of part 15 stations that are run by hobbyists. Supposedly, you can also setup as many transmitters as you want, as long as you don't go past 100mW, and your antenna is only 9.8 feet long (including feedline).
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Flack
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Re: Part 15 AM/FM transmitter

Post by Flack »

I really don't know anything about the radio stuff (all I know about radio broadcasting came from Pump up the Volume ... TALK HARD, HARRY!) but the idea of running a podcast at OVGE sounds super fun. I'd love to run an 8 hour show with different guests, interviews, etc. We could switch off main hosts every other hour or something like that. Hopefully we could both broadcast it and record it and put it online for other people to enjoy later.
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dstone
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Re: Part 15 AM/FM transmitter

Post by dstone »

Might not hurt to put together a few 10-15 minute pre-produced chunks so the broadcast could continuously run during a bathroom or shopping break or something (or if you didn't want to use the band or anything else that's super loud).

Should be pretty easy to put a kit together, just a small field mixer, a few microphones, small laptop for quick playback of pre-produced stuff (like stingers, station ID, background music, etc) and feed that into a compressor/limiter, then from that to the radio transmitter and a computer for streaming/archive.
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dstone
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Re: Part 15 AM/FM transmitter

Post by dstone »

Looks like the call's going out for OVGE exhibitors. Still interested in doing a broadcast from the venue? I'd be willing to provide the equipment to make it happen.
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Flack
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Re: Part 15 AM/FM transmitter

Post by Flack »

I don't think Icbrkr is going to make it to OVGE and he was the brains of the operation, at least as far as broadcasting over radio waves goes. I really don't know how to do any of that, other than talk into a microphone for 8 hours -- that part, I can do. Icbrkr showed me some of the stuff he does with his radio stuff over at 98pacecar's place and it was really interesting. I didn't realize how tied into the computer all his broadcasting was.
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ubikuberalles

Re: Part 15 AM/FM transmitter

Post by ubikuberalles »

I'm seriously thinking about getting a Part 15 transmitter on my own just for sh*ts and grins. Prices for kits are as low as $89 and assembled kits are as low as $176 (The prices for these things are all over the map. I've seen kits as high as $300 and assembled transmitters for as high as $1000). I doubt that I'll have anything ready for OVGE. However, if I did get the transmitter built and working I may bring it to the show.

I just need to figure out a motivation: something to get me excited about buying it (and building it). What would I do with it? I could hook the transmitter up to my computer in the Living Room and have the computer play tunes. I could then listen to tunes in my bedroom with whatever AM radio I still have. I could also set up my computer to send binary signals by having it broadcast multiple tones like a modem. I could then have an Arduino or other small computer pick up the signals and then download data and execute commands. I could start with a simple remote control. Have my computer emit a certain frequency on the transmitter and the receiver would be hooked up to a filter and a switch. Thus I could turn on and off lights. I could even control a robot with it.
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Flack
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Re: Part 15 AM/FM transmitter

Post by Flack »

I've been dreaming of buying one of these for years:

http://www.pcs-electronics.com/3000-stereo-transmitter-card-p-1664.html?osCsid=68033ff1a8697603eb78b2ee57175dd6

While I'm sure the 100mw one would be good enough, the 1 and 3 watt cards seem more, for lack of a better phrase, bad ass.
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ubikuberalles

Re: Part 15 AM/FM transmitter

Post by ubikuberalles »

They'd be more bad ass but they would also require a Radio license. :(
The price is Bad Ass: 140EUR for the 100mW, 170EUR for the 3W (Bad Ass) one.

You might even need a license for the 100mW model. I was reading up on Part 15 and the 100 mW limit was for AM broadcasting. They mentioned FM broadcasting and the power levels were significantly lower. However, the language was not clear so I may have misunderstood. Brian might know better.
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Flack
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Re: Part 15 AM/FM transmitter

Post by Flack »

I think you only need a license if you get caught.

Talk hard, Harry.
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