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Project Notes

#403 GY560 Frequency Counter

Checking out the GY560 Frequency Counter.



The GY560 Frequency Counter is an incredibly cheap but pretty effective bit of test gear, most useful for detecting radio frequency emissions with a measure of frequency and signal strength.

I think I first saw this in one of dazaro3’s videos like How to build a 2 transistor FM transmitter:



  • Frequency step : 200K (digital radio signal), 1K, 100Hz.
  • Testing distance : UHF : 8m, VHF : 5m.
  • Testing range : 50 MHz ~ 2.4 GHz
  • Antenna : pulling out antenna
  • Battery : 9V 6F22
  • Auto power off time : 1 mins. (except for the digital signal gear)
  • Operation : the only one button with all functions


The only one button with all functions.

  • Power on: short press
  • Power on and set step: hold button down on power on, will cycle through 1kHz, 200kHz, 100Hz. Release button on desired step.
    • This mode will be remembered after restart.
    • 200kHz mode recommended for digital radio
    • 1kHz mode recommended for faster testing
    • 100Hz mode recommended for accurate testing
  • Hold: short press while on with hold/release display
  • Power Down: long press


Quick peek inside. Not much to it - just a microcontroller with input signal and display. Although the chip is unmarked, I wouldn’t mind betting that’s just a PIC.


Credits and References

Project Source on GitHub Project Gallery Return to the LEAP Catalog

This page is a web-friendly rendering of my project notes shared in the LEAP GitHub repository.

LEAP is just my personal collection of projects. Two main themes have emerged in recent years, sometimes combined:

  • electronics - usually involving an Arduino or other microprocessor in one way or another. Some are full-blown projects, while many are trivial breadboard experiments, intended to learn and explore something interesting
  • scale modelling - I caught the bug after deciding to build a Harrier during covid to demonstrate an electronic jet engine simulation. Let the fun begin..
To be honest, I haven't quite figured out if these two interests belong in the same GitHub repo or not. But for now - they are all here!

Projects are often inspired by things found wild on the net, or ideas from the many great electronics and scale modelling podcasts and YouTube channels. Feel free to borrow liberally, and if you spot any issues do let me know (or send a PR!). See the individual projects for credits where due.