Sean Breheny wrote:
>
> At 03:20 PM 12/14/98 PST, you wrote:
> >Scope probes tend to have too much capacitance in them, sometimes
> >stopping the oscillator all-together.
>
> Yeah, I wonder if he is even using an x10 probe?

He is not. In fact he would be embarassed if they saw what was attached to his
scope.

> If not, the cap of the probe could easily be 60pF.

This explanation (probe capacitance) make a lot of sense.

With R = 10k P = 20pF the expected OSC1 frequency is 2.66mhz which is almost
exactly(!) 4 times the OSC2 frequency I measured. So I guess the conclusion
is... OSC2 measurement, valid; OSC1 frequency, bogus.

So, thanks very much for clearing this up.

Dan