[Test-Equipment] crystal checker

[Bob Roehrig]

What I have used quite successfully to test xtals is a simple osc using 2 
sections of a TTL quad nand gate (7400). Circuit is simple:
Pins 1&2 connect to one side of 32pf cap.
Pins 3,4,5 connect together.
Pin 6 connnects to one side of xtal.(this is the output)
Other side of xtal connects to other side of cap.
Connect 680 ohm resistor between 1,2 and 3,4,5.
Connect 680 ohm resistor between 3,4,5, and 6.

All 32 pf load parallel mode xtals should be pretty close to proper 
frequency here. Series mode (overtone xtals) will oscillate on their
fundamental frequency. Usually xtals below 20 MHz are parallel mode.
Not sure how low it will work but I have tested ones as low as 1MHz.

                               Bob Roehrig
                     Aurora University    Telecom dept.
                            broehrig at aurora.edu
                          K9EUI  W9ZGP  WD2XSH/19
                     630-844-4898      fax 630-844-4222
                     "Nostalgia is a thing of the past"