The Model 1856C frequency counter is capable of measuring from 5 Hz to 2.4 GHz and features a special 50½-terminated input for use in with VHF, UHF, microwave, and cellular telephone ...

[mircemk] had previously built a frequency counter using an Arduino, with a useful range up to 6 MHz. Now, they’ve implemented a new design on a far more powerful STM32 chip that boosts the m… ...