Hysteresis Oscillator - No Chop

[gluedtogether]

So I tried building the hysteresis oscillator according to the layout below and have not had great success.

http://www.aronnelson.com/gallery/v/Choklitloves-album/album16/hysteresisoscillatorlayout.png.html


The LED comes on, but no chop. I didn't nave one of the .33 uf caps, but have tried a couple in there to no avail. The traces all look clean. I got the 555 chip from radio shack, but tried a couple different ones as well. One from smallbear seemed to work intermittantly but the chop was extremely fast and it didn't stay on. Any suggestions would be great.


Thanks
Mike

[gluedtogether]

bump?

[Papa_lazerous]

I noticed it says the layout is unverified on that link, if you follow this link http://geocities.com/worthekik/hysteresis.html there is the schematic there aswell as the layout you are using.  hopefully using the schematic you will be able to trace back any mistakes you might have made

[Wounded Paw]

i made up my own pcb from that schematic and it works fine.

[Papa_lazerous]

possibly a layout problem.....or a silly mistake that you just cant see

[gluedtogether]

Thanks, I will trace through. Hopefully It something simple I missed the first time around

[oldrocker]

T