Simple crystal tester

Dilshan Jayakody writes: This is simple Colpitts oscillator to test commonly available passive crystals which range between 2MHz to 27MHz. This unit must connect to an oscilloscope and/or frequency counter to get the frequency of the crystal. This circuit is design to work around 9V to 12V DC power source. Both 2SC930 transistors can replace […]

1Hz to 10MHz frequency meter using ATtiny2313

1Hz to 10MHz frequency meter using ATtiny2313: This AVR-based Frequency Meter is capable of measuring frequencies from 1Hz to 10MHz with 1 Hz resolution. The hardware of this project consists of seven 7-segment displays, AVR ATtiny2313 uController, and a few transistors and resistors. The AVR counts input pulses for a precise 1 second  interval (generated […]

High precision decade frequency generator

Jbeale designed a high precision decade frequency generator based on a 26Mhz ovenized oscillator with stability of +-1 part-per-billion, or +-0.0000001%. The generator is controlled with a PIC16f1823 microcontroller, which provides interface and frequency division. Firmware, PCB and schematic are uploaded on his site. He also provided a link to Tom V.B. impressive site that […]