How to Listen to Morse Code on Ham Radio

By H. Ward Silver

In ham radio, Morse code signals are often referred to as CW, which stands for continuous wave. Early radio signals died out quickly because they were generated by sparks. Soon, however, operators discovered how to make steady signals, or continuous waves, by turning the signals on and off with a telegraph key. Thus, Morse code and CW became synonymous.

To tune in a Morse code signal, follow these steps:

  1. Set the rig to receive Morse code by selecting the CW mode and tuning to a frequency somewhere in the bottom 20 kHz to 30 kHz of an HF band.

  2. If your rig has more than one filter, set it to use a wide filter.

    A wide filter allows you to find and tune in stations, whereas the narrower ones block out unwanted nearby signals. You select filters with a Wide/Narrow control or with buttons labeled with filter widths.

  3. Adjust the tuning control until you hear a Morse code signal.

    The pitch changes as you change the receiver’s frequency. Tune until the pitch is comfortable to your ear.

    A low tone (300–600 Hz) is most restful to the ear, but a higher tone (500–1200 Hz) often sounds crisper. Most radios are designed so that when you tune in a signal with a tone or pitch around 600 Hz, the transmitted signal is heard by the other station at a similar pitch.

    If you prefer to listen to a note more than 100 Hz higher or lower, check your rig’s operating manual to find out how you can adjust the radio to accommodate your preferred pitch.

  4. When you tune in the signal at your preferred pitch, select a narrower filter (if one is available) to reduce noise and interference.

    If the frequency isn’t crowded or noisy, you can stay with a wider filter.