Crystal Oscillator

Posted on Feb 6, 2014

I currently have three: a really old optoelectronics Opto-7000 which I don`t use much, a newer Mitronics MIC-1028, and my most recent acquisition, a used Tektronics 2236 `scope purchased at Dayton 2009, which has a very handy frequency counter built-in. I was working on a recent project and found the Tektronics and theMitronics counters were annoyingly out ofagreement.

Crystal Oscillator
Click here to download the full size of the above Circuit.

How to check the calibration So I built this 10 MHz crystal oscillator. There are a lot of crystal oscillator circuits if you search the internet, some of them amazingly complex. I wanted one that was simple, had no tuned circuits, and could be tweaked to get it on frequency. I use my shortwave receiver tuned to WWV at 10 MHz. I adjust C2 to zero-beat with WWV. This can most easily be heard when the tones are present, since mis-tuning makes the tones sound wierd. Once zero-beat, the frequency counter should read 10 MHz too. I found my Tektronics was spot on, and theMitronics needed adjustment, which was easy to do since the calibration trimmer was accessible through a small hole in the front panel. Since completing this project, I came across an interesting article on how to calibrate a counter (that has an internal 10MHz oscillator) without any extra gear (besides a receiver for WWV). Have a look at VE2ZAZ`s blog. It doesn`t work with my Mitronics counter, though, so it must use a different reference oscillator frequency.

Leave Comment

characters left:

Related Circuits

  • New Circuits



    Popular Circuits

    DC-10Khz frequency-voltage converter
    Four channel synthesizer
    Discrete 0.5-300 ms Monostable Multivibrator
    H bridge switch for small motors
    Logochip Creative Works
    Remote-Controlled Fan Regulator
    Schematic Diagram LM35 Smart Heater Controller Project
    Brightness controller for low power lamps
    load switches with zero power MOSFETs
    Automotive Buses and Vehicle Bus Description
    Single multi-lamp switch control circuit 2