> That's great Dieter,
>
> How do different capacitor value affect the range in time, i.e. if I
> replaced 100nF with 1000nF or 10nF what sort of difference would I
> notice

100nF -> 1000nF = tenfold the time or period
100nF -> 10nF = tenth part of the time or period

> I was thinking that if it's a large difference to make a little pcb and
> have an additional switch to change from standard to new value.
>
> Thanks
>
> David

The capacitor value is proportional to the time or period (e.g. doubling the
capacitor value even doubles the time or period, when the capacitor value is
increased tenfold even the time or period increases tenfold).

Best wishes
Dieter Doepfer