Ham Radio General Class Practice Test

When sending CW, what does a "C" mean when added to the RST report?

1. Chirpy or unstable signal

2. Report was read from S meter reading rather than estimated

3. 100 percent copy

4. Key clicks

The correct answer is: Chirpy or unstable signal

In the context of sending Morse code (CW), the addition of a "C" to the RST report specifically designates the signal as "Chirpy" or unstable. This is important in communication as it informs the receiving station that the signal is experiencing irregularities in tone or quality, which could hinder effective communication. Providing this detail allows the operator to understand the signal's condition, and that adjustments might be needed for better clarity or to change the transmission settings for improved reception. The other options address different aspects of signal quality. While a report read from an S meter refers to how the strength of a signal is gauged, indicating it was taken from a specific meter reading, it does not pertain to the stability of the signal itself. Reporting a 100 percent copy implies that the message was received perfectly; however, this does not indicate instability. Key clicks refer to unwanted artifacts or noises produced during the keying of a CW signal, which is also unrelated to the clarity or stability of the signal itself. Hence, the "C" specifically focuses on a character indicating chirpiness or instability in the signal transmission.