AVR-Chat

At 03:47 AM 11/21/2003 +0000, nangkon wrote:

>Thanks for the info!
>
>Is there an instrument (maybe Oscilloscope) to measure 
>if the cap/crystal combination is ok? And what should 
>I measure (frequency)?

Probing a crystal will pull it off frequency, unless you use a special high capacitance, high impedance probe. 

What I use, is a shortwave recever, with BFO. 
This works on the radiated energy from the circuit, and does not affect the circuit at all.  If you already have a Sw receiver, then this is a very good technique, especially when you can calibrate to WWV at 10.0.. or 5.0.. MHz

I have been able to probe the crystal can, and get a recoverable signal on the scope, but it's not a very large signal, and you could be misled.