Description: 1Hz-50MHz Crystal Oscillator Frequency Tester Meter Digital LED Frequency 1Hz ~50 MHz Five-digit resolution (eg display X. xxxx kHz X. xxxx MHz or xx. xxx MHz) Measure signal amplitude up to 30 V 4-40 Meters can measure passive crystals Automatic range switching with different gate times Optional addition or subtraction of a frequency offset (programmable) Low component count: a PIC 16F628, 5-segment LED displays, a 20 MHz crystal and a few resistors Optional (configurable) power saving mode that automatically does not change the display off when the frequency substantially within 15 seconds USB 5V or DC5-12V power supply can be used Specification: Welding installation considerations, these steps: The components are welded on the back of the board (including good resistance capacitance microcontroller screen printing side), from low to high, the first principle, namely low welding components, such as crystal, capacitor, resistor, diode. The welding microcontroller header, and then welding, triode, knob, a power outlet. The back with a side cutter to short the pins as far as possible   Debugging steps: After completion of welding IC PIC16F628 microcontroller, note the direction of IC, the insert can damage the chip! Check the IC or against, such anti take timely correction. After the check, the electricity, the fourth digital tube display 0. said the installation was successful! Using the step of: Before measuring signal, please switch J1 jumper cap. blue terminals for the IN for signal input, GND GND for signal input signal amplitude does not exceed 30 V, otherwise the frequency meter damage. Before measuring crystal please switch the J1 jumper cap in JP1 insert 4 m to 40 m crystals can measure the crystal frequency Note: This is unassembled DIY Kits Package Includes: 1 Piece Frequency Meter DIY kit