TIME BASE OSCILLATOR |
Simple "Time Base Oscillator" for frequency counter or other application. Output square wave TTL: 1,25MHz; 2,5MHz; 5MHz; 20MHz.
Main oscillator is VTCXO 20MHz +/- 2ppm recovered from old UHF radio. Two ICs 74LS73 are used to divide the signal and one 74HC04 for sine/square conversion.
Time Base Oscillator schematic
PCB Components position
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