I build this just because i wanted a quick and easy project to kill some time.
All the necessary parts i had laying around.
In the end it looked like this:
It give a fair a mound of “Noise” according to my scope.
I have put it in a little enclosure, also i tried it on my frequency counter. It seams to resonate around the 1.7 Mhz.
R1 => 10K
R2,R4R6R8 => 1.2K
R3,R5,R7 => 22K
C1,C2,C3,C4 => 0.01uf ceramic
D1 => LED
D2 => 1n51A 5.1v Zener
Q1,Q2,Q3 => 2N2222
On -Off switch