On 25/10/2016 19:43, Michael Chare wrote:
On 25/10/2016 18:43, Harry Bloomfield wrote:
Michael Chare used his keyboard to write :
Would an elecrical oscillator such as the small ones shown in this
picture mind which way round they are installed?

http://tinyurl.com/jhfjnhd

The two pins are reversible (no polarity) and the physical orientation
doesn't matter either.

Thanks for all the replies. I could not find any markings and I am now
sure that I have not put it in the wrong way round.

Installed where? I have never seen a crystal that wasn't marked on the
outside of the can with the operating frequency or a code for same.

If you said what the application and frequency was it would be possible
to suggest a simple circuit to test it independently.

Watch xtals at 32768Hz are easily blown to bits unless you use a lower
drive power but usually survive a few days on the higher power. Most
other things will stand a fair amount of abuse from logic chips.

Some are tetchy about starting or are off frequency if the right load
capacitor network isn't placed around them. Older Meade telescopes are
an example where the RTC keeps appalling time and has to be reset almost
every session. They fixed it by adding a GPS function!

--
Regards,
Martin Brown