Simple Transmitter / Receiver

[Sleven]

I am trying to start a small project. My ultimate end goal is to have a small (as light weight as possible with a power source) transmitter that sends a signal to a hand held receiver. I would like the receiver to either beep at different rates (slow when far and steady like a metal detector when near) or have the sound the receiver emits change tone based on distance (deep when far, high when near). I would like the transmitter to transmit roughly 4 feet around itself so that more than one transmitter in a relatively small area will not interfere with the locating of another. I have no idea where to begin my research for this project. I have found some AM and FM transmitter/receiver projects but I am not sure if that is the best route to go for me. Any advice would be greatly appreciated.

 

[papunblg]

The TWS-434 and RWS-434 are extremely small, and are excellent for applications requiring short-range RF remote controls. Easily available.

See:




I think using those will be easy in the sense no need to make or adjust coils, no hard to find pf value capacitor etc.

 

[Sleven]

Thanks for your reply.

Is there a cheaper way to make the transmitter? Can I go to a hobby shop and buy some circuit boards and parts to make my own? I would like to have 15 or 20 of the transmitters and that will add up real quick at 25 bucks a pop.

 

[jiripolivka]

Dear Steven:

in our civilized world it is not legally allowed to simply operate a transmitter as its signal could cause interference to authorized frequency users. I would like to invite you to contact your local radio-amateur club or a licensed radio amateur who can help you with your project. Most you can learn by reading the ARRL Radio Amateurs' Handbook where you can also find examples of good transmitters, receivers and antennas suitable for your work.
If you cause an interference to authorized frequency users, you can be found by authorities and fined. Try to go a honest way!