Of the things you'll find on a technician’s workbench, a frequency counter is one of the easiest to use. Their main purpose, measuring frequency, is done by setting a few front panel switches. Spending a few minutes with a frequency counter and a test oscillator will show you what you need to know.
Connect oscillator to frequency counter using the BNC cable.
Turn oscillator and frequency counter power on.
Select a pure, unmodulated waveform from the oscillator: sine, triangle, or pulse.
Set the oscillator’s amplitude (output level) about halfway. Set its frequency to about 1000 Hz.
Set the frequency counter to the lowest frequency range. Set its gate to one per second. If it has a frequency/period mode, set it to frequency.
If the frequency counter has a "Hold" button, press it. The display should hold the same count. Press "Hold" again to resume normal operation.
Change the counter’s mode to "Period," if it has that mode. It should now display a time interval of about .001 seconds.
Change the oscillator frequency. The counter should show the new frequency momentarily.
Change the "Gate" setting. The display should update less often but with higher resolution.
For best performance, give the frequency counter a few minutes of power-on time to stabilize before use.