How Can I Broadcast a Message Into Outer Space Using Radio Waves?

[Tuts]

Hello!

I have been thinking of broadcasting a message into outer space. It sounds silly, I know, but that's just something I'd like to do for and with my niece. She's 8 years old and very interested in physics (as far as she understands it).

I have some knowledge in electronics, I think I could assemble a circuit that would transmit the message. I just don't know the details.

For example: which radio frequency should I use, so that it will escape the Earth's atmosphere? What is the power (W) needed for the message to reach some (a few hundreds, maybe) light-years, after it scapes the atmophere? What kind of antena should I use, so that the signal goes in a specific direction, thus reducing propagation loss?

I really would like to do this for her :)

Thanks in advance!

 

[tech99]

How will you know if it worked?
I am sorry but it is just not practical for you to do this.
But you could send a message to another country with a home made set-up and the right training.

 

[AlexCaledin]

What's really interesting to demonstrate , it's receiving the radio echo from the Moon.
Amateurs do it using frequencies about 146 (or 430 etc) MHz with a directed antenna similar to a classic tv one but with more directing elements. The transmitter power can be 1kW or more.

 

[JRMichler]

If you are in the United States, you need an amateur radio operator license. That, and everything else you need to know, can be found here: http://www.arrl.org/getting-licensed.

I think it's time for me to buy a copy of the ARRL Handbook if only to read about the spudgun antenna launcher.