I have a really nice old Sony portable radio from the late 60s that works great. Where I moved, there isn’t anything other than some foaming mouth jerks on AM radio. I would like to be able to hook up a transmitter to my house stereo to broadcast my cds, tapes, and records onto the little portable Sony AM radio I have so I can listen to that stuff in the garage where I am working on a car or whatever.
When I go to look up something that might work for that, I get autocorrected to FM transmitter. I want an AM one. Anyone ever have one of these or know of some?
Have you ever used a consumer-grade radio transmitter? I’ve tried some FM transmitters and they really aren’t that great. The power typically is pretty weak. Even in the car where the antenna is just a few feet away, the reception is not all that reliable. From what I’ve experienced, an FM transmitter won’t be useful even if you had an FM radio. I don’t know if AM would be any different.
The modern solution to your situation is to get a bluetooth transmitter for your stereo and get a bluetooth speaker for your garage.
Possibly? I’m not an expert on the topic (and IANAL), but it sounds like there are those who’ve argued that, under the FCC’s “Part 15” rules, if an AM transmission is 100 milliwatts or under, it might not require a license. (Note that the assembled small transmitter to which ftg linked on eBay calls out that its signal strength is, in fact, 100 milliwatts.)
Yeah I was thinking about the whole bluetooth thing, but I would still need to modulate the signal out of the blue tooth transmitter to AM somehow. The whole fun of the AM deal was that I rebuilt the Sony AM radio to look like it was brand new, and I wanted to be able to use it. Imagine, an AM radio playing Rusted Root or something that decidedly isn’t AM radio material. I was hoping that I could pump a couple watts of AM from the second story of my house and pick it up in the yard and in the garage and what not.
I was looking into a carrier station, which uses the power lines in your house to broadcast AM. Its supposed to be able to be picked up from 200 feet of a power line, and its legal to operate without a license since the transformer at the street kills the signal, but when I asked around at the local AV store for something they looked at me like I was a crazy two headed person.
Oh man, I know that is the logical answer here, but I put in lots of hours on the restoration of this little radio. It works like it is brand new. I even repainted the dial and polished the leather that wraps the unit. When I was in Oregon, there was still options on the AM dial that were palatable, but here at the Colorado/Utah border, you can imagine what gets screamed into a microphone on the AM dial.
The last time I turned it on, there was a guy that was screaming into the radio “Obama HUSSEIN’s Mooslim conspiracy to execute good Christians in the street in full sight of God and set up SHA-RA-RA LAW” and I had to shut it off again. I can’t even get a damn baseball game, major or minor league on the damn thing.
If I had a decent AM transmitter, I could show people what I spent hours doing. I know its stupid. Most things I do are stupid I guess. :smack:
There’s probably a better solution on that site, maybe build right into the radio, if you knew what to search for. That is, unless you really want the transmit-receive experience.
Not stupid at all, I figured there was an underlying reason for taking that particular route. Makes good sense to me. The cheaper, easier option ain’t always the way to go!
Are you handy? Get yourself a Raspberry Pi (cheap single-board hobbyist computer), download this software, plug in an antenna, load up the SD card with music and transmit away.
Caveat, you’ll have to know what you are doing to set up the transmitter program and figure out how to pipe music to it. Furthermore, the signal is generated by turning a voltage on and off so you must know how to select an appropriate transmission frequency (OK, this will probably be the commercial AM band) and solder up an appropriate band-pass filter, otherwise you will be spamming the entire radio spectrum with unwanted interference, which is not cool, even at 100 milliwatts.
I don’t think you want to set up a carrier current system, which covers a larger area than you need and is more complicated to set up. What you need is more along the lines of a “talking house” transmitter, commonly used in real estate to provide information for house hunters driving by individual properties.
I don’t have any personal experience with the devices, but the following link has information on one particular unit:
I found the direct link to that unit before I finished reading the thread. Quite a bit more information available there. There’s even an upgrade option to “internal component enhancement yields increased dynamic range and modulation levels. The resulting signal is even louder, fuller and more natural sounding.”
I saw some of those listed on eBay when I did my search. Didn’t pay much attentions since I assumed they did limited messaging. But if they have an aux in, selectable frequency, etc. then they are an interesting idea. Can be had used for less than $40.
Then thing Maus Magill points to is going to have atrocious audio quality (even by such AM hacks) and other issues.
And the Raspberry Pi software radio needs a really good filter. It will generate a square wave which will be seen as noise to a lot of devices.
I think that maybe the Talking House with the upgrade (which is essentially a compressor to level the sound and pump some gain) is probably the easiest way to go. Plus it kinda looks like I could put that into my component stereo system, and it has the whole VCR vibe to it.
I am still really interested in doing the carrier current thing though, just to see if I could pull it off. The schematic doesn’t look THAT complicated… but I am unsure about winding my own transformers.