How I setup an FM Radio Station

1. I ordered a 4W transmitter from http://fmtv.us/ for $259 (with antenna and shipping.)

The vendor told me this:
"The 4W transmitter covers a 10 miles radius if you live in a rural area, Normal coverage is 3~4 miles when used with a simple dipole antenna 10ft above ground. You'll have get RG6 cable from any Home Depot.

2. After initial testing - using my computer headphone jack I got the system working. Then I tested the headphone jack of a cd/radio player. It didn't seem to deliver a strong enough signal to the transmitter so I tested it with a mp3/radio player and found the mp3 radio would work. This would allow me to broadcast 12 hours of non - duplicated mp3 music (and repeat playing the cd) without using a computer. Since 250 songs pretty much cover all my favorite tunes I seldom hear the same song twice the same day.

This is the mp3 player/radio I used. It is available from Walmart for $25.
Durabrand MP3/CD Player with AM/FM Stereo Receiver, CD-2086 click here.

3. After you have the transmitter, antenna, and mp3 player you'll need cable to connect the antenna. I had a 50 ft roll of tv coaxial cable I used. I think that's R11 although RG6 cable is recommended. You'll also need a stereo jack that splits to left and right channels. I don't know what they are called but they are common. Radio Shack sells them. There is one in this photo.

Here is a photo of all 5 jacks connected. 1 goes to the mp3 player headset jack. On the other end two connectors for left and right channel go to the transmitter and the transmitter has the power supply and coaxial cable connected.

The last thing you'll need to finish the setup is 2 or 3 sections of top rail for chain link fence. It's easy to make an antenna pole out of them and they cost about $7 per 10 ft section. The only problem you may find is that they aren't tight when they are joined. Since it's not good for the antenna to wobble in the wind I cut a "v" shaped piece of metal, about 2 inches deep and 1/4 inch wide, out of the outside end and put a hose clamp on it to make it hold tight. Here is a photo.

Here is the pole with hose clamps at a connection.

Here is the final setup with all connections - notice the receiver is suspended. It gets VERY hot. It's better if it doesn't touch or come near anything that can burn.

My first section of the antenna pole was attached to a barn.

Since I started with a regular piece of 1" pipe (about 10 feet long) raised a few feet off the ground - and then inserted about 25 feet of fence rail my antenna is about 40 feet high. I don't know if that makes any difference in the range and clarity of the signal to raise the antenna higher but I think it could.

It's broadcasting Rock and Roll, Christmas Music and a few selected Country Music Tunes!

Final notes... The most important thing is avoiding other radio stations "stepping" on your signal. The transmitter is easy to set on any frequency so it's best to drive around in an automobile with a digital radio dial and check for dead air space in your area and use that frequency. Your broadcast will be killed within a mile if you use the same frequency as a local station.. or get too close to a powerful radio station's broadcast.

I am somewhat disappointed that there is distortion at a range over 1 mile and the signal dies out beyond 2 miles. Setting up the antenna correctly using only one section in a vertical position is supposed to be the key to making the signal reach out farther and clearer but I can't say that anything I have done to the antenna has made any difference. I probably need to get someone on the phone listening to the station about 2 or 3 miles away and tell me if changes are making any difference to their reception.

Anyway, I like the setup. I can roam locally, ride in my truck, visit my parents and listen to the commercial free music of my choice. And I may even have a few neighbors who can listen in if they find he signal.

As you know... there are several sound recorders that capture any audio that is passing through your sound card and saves the audio to an mp3 file. You can set the quality level and record music from external devices by connecting a simple cable from the device to your sound cards "line in" jack. If you sign up for 3 days of free music at satellite radio websites and capture your favorite music channels you'll have 72 hours and at least 1,500 songs, commercial free. You can put about 12 hours (250 songs) on one 700 meg cd.

Since converting audio to mp3 reduces the quality I wanted to directly connect my satellite receiver to the transmitter. However I could not get this to work. The satellite receiver broadcasts a weak fm signal on one frequency. A radio nearby easily picks up the signal and plays it but when I turned on the FM transmitter it killed the satellite reception. I tried to separate the frequencies as much as possible but that didn't help. I will get more cable and try to separate the radio from the FM transmitter 20 or 30 feet and see if that resolves the interference problem. It would be ideal to have a transmitter that could gain input from one frequency and send it out on another. There are many small fm transmitters that plug into a device and send a low powered fm signal to nearby radios/tv's etc. If these signals could be rebroadcast with a more powerful FM transmitter it would make a nice wireless system that was easy to setup and would be easy to move.

Comments welcome, send email:

tblount@mchsi.com