Frequency Counter 6 Digits

Features

• AliExpress listing
  • AKA: PLJ-6LED
• Frequency reference with temperature compensation type voltage controlled crystal oscillator (2.5 ppm VC-TCXO).
• Adopts gate control mode and the accurate time algorithm is unique.
• Gate (refresh) time is 0.1 seconds, real-time display of frequency.
• The precision of frequency measurement 10Hz/100Hz (Rotated the right one) optional.
• Dual frequency design, intermediate frequency value and plus / minus mode can be preset, and do not influence each other.
• Display driver using the LED chip digital tube display, high brightness, less external interference.
• Adopts six 0.56 inch digital tube display, automatic blanking invalid zero, eight stage adjustable brightness.
• Simple circuit, reasonable structure, double button control, simple operation.
• All settings are automatically saved, boot directly call.

Specification

• Working voltage: DC 8V-15V (reverse polarity protection)
• Working current: 90mA (max)
• Input impedance: high resistance
• Measuring range: 0.1 MHz to 65 MHz
• Accuracy: 10 Hz
• Sensitivity: better than 60mVPP
• Display digits: Six common anode LED display , the highest display six digits
• Size: 9cm x 2.5cm x 2cm .
• Connectors
  • RF IN (input): HX2.54-2P socket
  • ICSP (programming interface): 2.54-6P Pin
  • DC IN (Power Interface): HX2.54-2P socket

Connections

Testing

Build into case

• Power and input wired to card
  • Jacks were too tall for box depth to close securely
• Two pushbuttons wired to Upper/Lower pushbuttons on card
• Mini-360 Switching Regulator
  • 9-24 VDC input
  • 7 VDC output
    • Lowers stress on 7505 regulator on the card (more stable due to lower temperature)
  • Hot glued into case
• 2.1x5.5 DC jack
• BNC front panel mount jack
• 100 x 60 x 25 mm Black Plastic Enclosure

Calibration

• Use GPS output as frequency source
  • GPS output is set to 8 MHz
• Adjust control with plastic or ceramic screwdriver