subCW

subCW is a term encountered in some radio communications discussions to describe the use of a Morse code (CW) signal transmitted on a subcarrier within a larger audio or RF signal. It is not a formally standardized mode or protocol adopted by major standards bodies, and its exact meaning can vary between sources.

In common usage, subCW refers to conveying CW information on a secondary carrier that modulates or rides alongside a primary signal. The subcarrier is typically separated in frequency from the main carrier and can carry a separate CW signal without occupying the primary channel’s bandwidth. Practitioners may implement subCW in analog or software-defined radio environments, using filtering and demodulation techniques to recover the CW on the subcarrier while the main channel carries voice or data.

Technical considerations include the choice of subcarrier frequency, modulation scheme, and bandwidth constraints. Subcarriers must be carefully isolated to avoid interference with the main channel and other users. The approach can offer advantages in mixed-traffic links where the primary channel carries one type of information and the subcarrier provides signaling, telemetry, or low-rate control data. However, subCW is not widely standardized or deployed in modern commercial systems, and it remains primarily of interest to hobbyists, researchers, and historical enthusiasts exploring multiplexing concepts and legacy techniques.

See also Morse code, CW, subcarrier, multiplexing, and software-defined radio.