I want to add a decently powered (~5 mile range) FM transmitter to my car stereo, a something like a radio station on wheels. I want to be able to listen to music from my car on any FM reciver within range. I think this would be really cool when I'm at a ski resort, and rather than bringing a limited amount of music with me in my mp3 player, I could bring a small FM tuner, which would be small, never skip, power-conserative, etc.

How hard would this be to accomplish? What kind of hardware would I need? What kind of antenna could I use? I'm assuming my power antenna can't be used to broadcast as well.

I've always dreamed of doing something like this, and was wondering if anyone has done something similar, or if there is a reason it wouldn't work at all.

Thanks!
- Eli

Is that actually legal where you'd be using it? It certainly wouldn't be in the UK.

You need to post to alt.radio.pirate . Try doing some Google groups searches and I think you'll find a good deal of information. BTW in the USA this is also quite illegal for the distances & power you're considering.

-Zeke

"I'm dedicating this unusual song to an unusual person who makes me feel kind of... unusual."

I do think it would be illegal, but I got a catalog from Ramsey Electronics this week with some interesting stuff in it.

Well yes, it probably is illegal at the power needed to travel ~5 miles. I figured my saving grace is that it will most likely never broadcast from the same location for more than 8 hours (while I'm snowboarding), it will be in very sparsely populated areas, and will only be on at very random times. I would like to be able to adjust the power level so it could be legal at times/illegal when I need more range.

I want to build this all into a permenant enclosure in my trunk along with the amps for my stereo and my subs.

- Eli

Happy owner of a 2000 Volvo S70 & 30gb unmodded Rio Car

The FCC can find you well within an 8 hour timeframe. especially with your car stationary.

In reply to:

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The FCC can find you well within an 8 hour timeframe. especially with your car stationary.

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Although it's possible, it would be highly unlikely. The FCC is a government agency, it's doubtfull you could call and talk to a real person in an 8 hour period - say nothing about getting them to leave their warm office and going out in the field to work.

In reply to:

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Although it's possible, it would be highly unlikely. The FCC is a government agency, it's doubtfull you could call and talk to a real person in an 8 hour period - say nothing about getting them to leave their warm office and going out in the field to work.

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Plus the fact that someone has to call and complain first. The FCC doesn't monitor all the frequencies all the time especially since the decline of the Amateur Radio and CB hobbies. And if he's using a frequency nowhere near a broadcaster's and he's in a somewhat remote area I wouldn't think he'd have to worry.

I think it's a great idea.
I was thinking of something like this myself for my shop. Since allot of the equipment I use is very noisy plus the fact of when I have to go into another part of the building and can't hear my Empeg an FM transmitter with a little bit of power would be great. I could get a cheapy walkman style radio and a single ear bud so I can still hear other people.

Definitely illegal. If you live in a big city like London or NYC, then I'd worry about getting busted. But if you live in Fuckwitzville, USA then I'd say your chances of getting busted are slim, especially if you broadcast on different frequencies (and aren't interfering) and at different times. If you want to broadcast 5 miles, then I think you'd need a pretty powerful amp, unless you wanna mount a 20 foot antenna on your car. I'd say for about a grand you could get a high quality, powerful amp. Hook that biatch up to your 12v, plug your empeg RCA's into it, rig up an antenna and you're all set. Then go to local businesses and ask if they want to advertise on your new radio station....

I was thinking of something like this myself for my shop

You can get a package of stereo headphones, with a small transmitter that broadcasts at the lower end(88) of the FM band, range about 2-300 yards. You can get them in the UK, with a sticker saying that you can't use them!, so you must be able to in the US. Novelty and cheapo shops might be more fruitful than hi-fi or electronics!

Obviously it would also work with a small portable, as you suggest.

...also dead handy if you're stuck with a hire car with no cassette slot/aux input and want to use your Empeg.

N.B. I forgot to mention that the stereo headphones you get in the same box, work perfectly well as an FM radio, ideal for the garden/a bit of privacy - the whole lot only cost around £20 - I'll check if they have a brand name.

rather than bringing a limited amount of music with me in my mp3 player, I could bring a small FM tuner

Try as I might, I can't grab the logic in this one,

(1)you can get MP3 players with loads of hard disk storage, for much less than the price of all your illegal transmitting kit - and the only risk of prosecution is for a guy from Sony to turn up and handcuff you for ripping his product copyright.

(2) you can make selections as you go along with an MP3 player, instead of having to listen to a playlist/random selection at the other end of a radio wave. That strikes me as like having a plastercast on and wanting to scratch your leg!

(3) When you're laying back on your mountainside, with sweet music drifting over you, and suddenly it goes silent, you're a heck of a long way from the guy that's nicking your Empeg.

(4) A nice guy with a good idea down on projects has just floated a thread with legs for fitting a battery and charger into the spare hard disk slot to make your Empeg truly portable.

If you don't mind a little work, I'd suggest getting a cheap build it yourself tuner kit and a 5W amplifier to go with that, capable of transmitting a few MHz below the FM band. Then get a cheap walkman or similar, open it up and find the tuning capacitor and also place that some below the FM band.
That way you will atleast not disturb any commercial station... Just watch it so you don't touch the police/military frequencies

// Jonathan

Sorry for the delay, all the transmitter box says is: "Datawave, Wireless man - for the world sound" - not even a country of origin.

I've tried that route. The reason I was contemplating trying out the higher power Xmitter is my shop is a very old and well built building. With a lot of metal work in it. It tends to kill radio signals of all kinds.
I also intend on going with just a single earbud since my boss has a thing against headphones.

DON'T DO THIS!
There are reasons for those restrictions.

Rolf
Licensed Radio Amateur

I'm a Radio Amateur as well and I'm not talking about a 50-100watt transmitter.
I'm thinking about 1watt to 5watts (absolute max) just enough to penetrate through my building. AND on a part of the band that's dead.

Hi,

I really can imagine, how nice this would be. But deep in my heart I have a problem with this kind of radio station.
To transmit your music you won't need much, but how do you want to control your empeg? Don't you want to skip or search some songs? With a normal FM-transmitter you will get a one-way transmission. So if the distance is low, you might get what you want with a wireless lan? But then you have to use a small notebook or something like that. The antennas aren't the problem, you'll get any kind of antenna even for your car (I'm sending my position from my car via 145MHz and I got an 16V-antenna, like the original especially for this 2m-band).

regards,
Rolf

For a similar App I have tried JW120 Wireless Headphones,
http://www.jensen.com/wireless/jw120_linx.asp

It's a Beltpack receiver so you can use earbuds, and is a 900mhz device so it is not transmitting on any commercial bands, which also I guess makes the content you are transmitting a little more private, they claim 150 foot range, but in reality it starts degrading in the next room and certainly isn't up to scratch for listening outside the house in the garden,

But for a short range the Jensen wireless kit is really cool, and sounds great, you can dock it with a lead to recharge the beltpack's batteries which last a long time, the only drawback for my application is the range,
so I have been considering boosting the power output usng one of these Motorola 344066F Linear Amplifier Modules
http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=1941764142&rd=1

I wonder if any of you Radio Amateur's reading this thread may have any better ideas of how I could simply boost the RF Power output, is there a better way to go?

Gazz
Alice Springs
(Middle of Nowhere)