Audio transmitter

[Ibraim]

First, i'm new here, so, nice to meet you! =)

Hi, on te internet there are a lot of simple projects of audio transmitters, but only in radio frequency. Do you know any circuit that works at a frequency that can't be captured by a radio? I need to get the signal through an another circuito, made by me.

Thanks!

 

[BobK]

Infrared would be an option, but you have to have line of sight between the transmitter and receiver.

Bob

 

[Ibraim]

Thank's bob, yes, it would be a problem. Isn't possible to create a circuit out of the radio frequency?
A radio works between 88 and 108 Mhz, the transmitter has to be small, but the receptor doesn't...

Any idea? =/

Thank you!

 

[BobK]

Thank's bob, yes, it would be a problem. Isn't possible to create a circuit out of the radio frequency?
A radio works between 88 and 108 Mhz, the transmitter has to be small, but the receptor doesn't...

Any idea? =/

Thank you!

88 to 108 MHz is the FM band. This is not all radio frequencies. Your initial post sounded like you wanted a means of transmitting audio that did not use ANY radio frequencies.

Of course you can use frequencies outside the FM band. Amateur radio uses various other bands, for instance.

Bob

 

[Ibraim]

I'm sorry, you're right! I mean something different of radio stations, and not the entire spectrum!... Do you know any circuit? The frequency is not important if i can't get the signal with a radio. Recalling that the transmitter has to be small.

Thanks a lot!