Paraphrasing Rear Admiral Joshua Painter in "The Hunt for Red October":

Engineers don't take a dump, son, without a schematic.

ak

 

Here is a schematic of the 555 frequency generator and the divide-by-two circuit to make a true 50% duty cycle. This example is for a 1KHz output, alternating high on the points labelled "Ch.1" and "Ch.2". The "Out" pin (3) of runs at 2KHz.
Note the capacitors in the circuit. Especially when using a 555, bypass capacitors are a necessity for stable operation.

 

Here is a schematic of the 555 frequency generator and the divide-by-two circuit to make a true 50% duty cycle. This example is for a 1KHz output, alternating high on the points labelled "Ch.1" and "Ch.2". The "Out" pin (3) of runs at 2KHz.
Note the capacitors in the circuit. Especially when using a 555, bypass capacitors are a necessity for stable operation. View attachment 114386

Great, thanks.

So, the differences in my 555 circuit are;

1) No caps C¹ and C² between pins 8 and Gnd
2) An extra 4.7nf between pin 6, 2 and Gnd
3) A 5k trimpot between pins 7 and 8
4) A 500k pot between pins 6 and 7

Bear in mind that mine is still in the prototype stage.

The only difference with the 4013 circuit is the 0.1µf Cap (or lack of)...

On my way back to the workshop now, so let's see.
I'll copy this schematic.

Thanks

 

Paraphrasing Rear Admiral Joshua Painter in "The Hunt for Red October":

Engineers don't take a dump, son, without a schematic.

ak

I promise that I shall do my best to give you a schematic... so that you finally take a dump....