By John Papiewski – Updated Mar 24, 2022

On any technician’s bench, a frequency counter is one of the simplest yet most essential instruments. Its primary function—measuring signal frequency—can be performed with just a few front‑panel adjustments. This guide walks you through the basic steps, using a test oscillator to illustrate each setting.

Step 1: Connect the Oscillator

Attach the oscillator’s output to the frequency counter’s input using a BNC cable.

Step 2: Power On

Turn on both the oscillator and the counter, allowing each device a moment to warm up.

Step 3: Choose a Clean Waveform

Select an unmodulated, pure waveform from the oscillator: sine, triangle, or pulse.

Step 4: Set Oscillator Parameters

Adjust the output level to roughly 50% of its maximum and set the frequency to about 1,000 Hz.

Step 5: Configure the Counter

• Select the lowest frequency range. • Set the gate time to 1 second. • If available, choose frequency mode rather than period.

Step 6: Use the Hold Function

Press the "Hold" button to freeze the display; press it again to resume live measurement.

Step 7: Switch to Period Mode

If the counter offers a period mode, enable it. The display should now show a time interval close to 0.001 seconds.

Step 8: Verify Frequency Change

Alter the oscillator’s frequency; the counter should momentarily reflect the new value.

Step 9: Adjust Gate Settings

Modify the gate time to observe a trade‑off: longer gates reduce update frequency but improve resolution.

Things Needed

• Frequency Counter
• Oscillator or Function Generator
• All‑female BNC cable

TL;DR

For optimal performance, allow the frequency counter a few minutes of warm‑up before measuring.