200 Yard FM Transmitter

200 Yard FM transmitter

When I was running a larger haunted house I wanted to be able to both advertise and broadcast the music and sound from the haunted display. I had everything I needed to make a short range FM transmitter that would have a range of around 150 to 200 yards. After making the transmitter I was able to pick up the signal from my car from blocks away. This unit using nothing more then a big antenna and a cheap FM transmitter like the ones used to connect mp3 players to older cars. This one was removed from an old IPod dock I got from a yard sale for $1

What you will need:
1. Small FM transmitter(the type used for a car)

2. Large antenna

3. Project Box

4. 5 volt power supply

5. Male-Male 3.5 mm Cable and an Audio source

6. A few Nuts and bolts

7. Super glue

The setup is very simple, I found that the antenna for the transmitter I had (pulled from a ipod car adapter) Was simple using the ground connector when it was connected to the rest of the unit, So All That was needed was a large antenna attached to the ground line and I could increase the signal range of this transmitter. To locate the antenna wire in other units you should be able to open them up and look for a single wire that is attached at one point, typically it is coiled, or a thicker trace on a circuit board that is marked, you can sometimes find out where the antenna is by googling around a little for the specific model of transmitter you are using. I decided to use a telescoping antenna pulled from an old RC remote. Then all you need to do is add a wall wart power supply to eliminate the need for batteries and allow it extra current if needed, put it all in a nice enclosure, and connect it to you audio source.

The Basic steps for making one of these is to gather the parts, You will then drill a hole for the antenna in your project box and mount the antenna, Bolt or glue the transmitter to the box this will depend on the box your using and the antenna type, connect it to a 5 volt wall wart power supply to power the transmitter, Solder or bolt the antenna wire to you new larger antenna. Connect this 3.5mm wire to your chosen audio source and your ready to broadcast.

This setup is more then enought to cover a block or two around the haunted display, and it was used to advertise a few days before we opened and also to broadcast music for my singing pumpkins, and to broadcast the sound tracks when we are open. When using this be sure to pick a radio station that is not currently broadcasting so that you don’t have to deal with interference.

After you check all the wiring and make sure everything is in place, you are ready to test the system. Connect it to power and connect an audio source and enjoy.

Any questions or comments email: HauntHacker@outlook.com