The frequency meter by use the LC resonance circuit that adjustable until the frequency show peak amplitude.
This circuit use a simple ideal is the calculator count a frequency within range 1 second. This time base is generated by IC-555,on astable multivibrator form. How it works The…
A cheap digital frequency counter kits. It works great, can measure frequency up to 1GHZ in 19$ only. But it's a little brighter so not clearly read. My son fix easily this problems by Installation film Cars. Makes Digits display very clear.