Try a search using "Tone Burst Curcuits"

You should be to find something you can use.

73
Danny, K6MHE


On Sat, 28 Feb 2004 21:57:01 +0100, "Gery Duyck"
wrote:

I want to make a microphone with quindar tones rogerbeep's.
(as on: http://home.pacifier.com/~garyn/quindar.html )

Anyone knows a circuit for this ?

73'
ON4GDK Gery