[Boatanchors] Testing a crystal

[Tom B]

Hi Ian,

Thanks.  I tried it on my network analyzer and got nothing so I think 
the crystal is absolutely dead.  I didn't want to try this test earlier 
because I wasn't sure if the crystal would take the power output from 
the network analyzer, which only goes down to -10 dBm, but is much 
happier at 0 dBm.  I tried this one another crystal and got exactly the 
response I would have expected from a good crystal.

Now to buy a crystal.  Too bad National is gone. Quartslab and Bomar are 
my best bet now.  I am inclined to go with Quartslab. Anybody got any 
other recommendations?


Tom

On 7/8/2018 9:29 AM, Ian Wilson wrote:
> I would aim at keeping the power dissipated in the crystal at or below 10mW.
> If the crystal is looking into something like a 50 ohm load then if you
> keep the
> drive voltage less than 1v or so then this should be safe.
>
> Note that the Q of the crystal is so high that you will not be able to
> 'land' exactly
> on it unless you are using a digital signal generator (and you may have to
> watch
> the scope trace very closely to see the blip).
>