Ham Radio General Class Practice Test

What type of transmitter performance does a two-tone test analyze?

1. Linearity

2. Carrier and undesired sideband suppression

3. Percentage of frequency modulation

4. Percentage of carrier phase shift

The correct answer is: Linearity

The two-tone test is a method used to analyze the linearity of a transmitter's output. In radio communications, linearity refers to how well a transmitter can maintain the relationship between the input and output signals across its operating range. During the test, two closely spaced tones are input into the transmitter, and the output is measured to observe how those tones are affected by the transmitter's non-linear characteristics. If the transmitter were perfectly linear, the output would consist solely of the two original tones at the same amplitudes, without any distortion. However, in real-world scenarios, non-linearities in the transmitter can generate unwanted harmonic frequencies and intermodulation products. By evaluating the output during the two-tone test, operators can determine how well the transmitter performs in maintaining linearity and identify any significant distortion that may impact signal quality. The other options focus on different aspects of transmitter performance. Carrier and undesired sideband suppression relate to the output signal's purity and how well the transmitter rejects unwanted frequencies, which is not the primary focus of a two-tone test. The percentage of frequency modulation and percentage of carrier phase shift deal more with modulation techniques, which are not the primary parameters assessed by a two-tone test. Thus, the primary function of the two-tone test