Help/ Ideas on micro beeping transmitter & receiver

[jshelley]

I need to build a transmitter of some type, very small. Preferrably one that simply emits a beeping noise that is audible only to the receiver. The receiver size is not terribly important, only that it is portable/handheld. The transmitter will have to be light and be able to fit into the end of a ball point pen for example. The range will not have to be very far, maybe 300 feet or so. Is this going to be possible? I have thought that maybe even some form of a magnetic field detection receiver might work, but I don't have enough knowledge in that area. Anyone have any ideas?

 

[mramos1]

Not far maybe 300 feet. That is a long way? Using magnetic feild? Fit in the end of a ball point pin?

I will take one too when you have it made.

What are you tring to do, maybe there is a better solution?

 

[audioguru]

He is probably another terrorist, but he doesn't like to blow himself up!

 

[mramos1]

Ahh. Explains the 300 feet. 100 should be safe. I do not think they will let you on planes with a ball point pen anymore either though.

 

[audioguru]

A bunch of terrorists might all get together with their ballpoint bombs and blow themselves up and cause a lot of damage. Why don't they do it in the middle of a desert??

 

[zachtheterrible]

So, u just wanna hear a beeping noise over your receiver? I'm guessing that you actually want to be able to find the direction of the beeping.

Check this out: https://www.jbgizmo.com/page23.html

Not sure that the transmitter will fit inside a ball point pen. I've built the regenerative receiver and it works great! If you want better range, you would probably want to build the superregenerative receiver, plus you can hear airplanes with it! A regular FM radio would probably allow you to hear the beeping though.

Build the transmitter first, and then decide if you want to build the superregen.

 

[mramos1]

Audioguru:

Or they are looking to take out paintball friends by giving them free pens before the game.