9A42 D
 An operator reports that calls can be made with the HF/MF communications equipment on 2182 kHz, but that greatly reduced power is indicated on all higher frequencies. After verifying that the transmitter functions properly into a dummy load, the antenna tuner of the system could be investigated by:
A. Observing changes in variable component positions or relay selections as other channels are tried.
B. Observing the coupler output with an oscilloscope of suitable bandwidth.
C. Observing the reflected power between the transmitter and the coupler.
D. Observing changes in variable component positions or relay selections as other channels are tried and observing the reflected power between the transmitter and the coupler.
