How do I test PIC external Oscillator with scope?

Johannes · Posted: Thu Dec 11, 2003 11:14 pm

Thanks guys for all the information. I really appreciate the awsome response.

Cheers,
Johannes

neil · Joined: 08 Sep 2003 Posts: 128

Hi, I have a Tektronix TDS3034B which I find OK for all my work. RF, analogue, logic etc. I have had problems seeing false waveforms due to aliasing and now accept this as a 'reality check' I have to do when I'm looking at high frequencies. Just look at the timebase setting and make sure it is correct for the frequency you expect to see!

One last thing, may sound silly, but could you have had the probe setting on 50ohm rather than 1Megohm when you first tried to look at the xtal, then on a subsequent power off/on of the scope defaulted back to 1 Meg, clearing the problem? This is not always easy to notice looking at the scope and would definitely have caused it to stop oscillating!!

Regards,
Neil.

neil · Joined: 08 Sep 2003 Posts: 128

Hi, I have a Tektronix TDS3034B which I find OK for all my work. RF, analogue, logic etc. I have had problems seeing false waveforms due to aliasing and now accept this as a 'reality check' I have to do when I'm looking at high frequencies. Just look at the timebase setting and make sure it is correct for the frequency you expect to see!

One last thing, may sound silly, but could you have had the probe setting on 50ohm rather than 1Megohm when you first tried to look at the xtal, then on a subsequent power off/on of the scope defaulted back to 1 Meg, clearing the problem? This is not always easy to notice looking at the scope and would definitely have caused it to stop oscillating!!

Regards,
Neil.