BATTERY OPERATED TRANSMITTER

Go to your electronic shop. Communica in SA have a lot of kits ranging from FM transmitters to whatever. (I am a sucker for buying this stuff and save it in a drawer for one day when I am on pension - only to find now that the components and instructions were separated).

Back in my Crystal radio youth days I did manage a transmitter on AM.

Thanks for that - Waiting for a miracle answer

Buy a cordless door bell. They are cheap and readily available, and the design work's been done.

You're on the right track, but we've 'bombed-out' trying to reconfigure it. (We're not that smart)

One of the other CR4 participants here had some simple projects for security using discarded cell phones. Check out this thread for some ideas.

Chris

Sounds good. I'll have someone check that out.

This project would be much easier with logic using a programmable chip (and programmer) in my opinion. Otherwise creating time delays and conditions would require a timer, logic gates, or hold-in relays that integrate to a transmitter. Relays can drain battery life maybe faster than desired.

With the logic, low voltage and minimal power consumption are available. Anything else I can imagine at this point requires 12vDC or 120vAC.

Are you switching on a contact with this device or just blinking lights and beeping?

Thanks for that. I'll 'bank' your response and pass it onto the someone who knows what you're talking about! And "Yes," switching on a contact. Further, 'life on' is very short, but 120V is something to consider.

Gadget Shack has a few, and so does Dimango

Thanks. Never knew of those. We'll check them out!