If power output indication of a remote controlled transmitter falls to zero, but video and audio monitors function normally, what is most likely the cause?

The situation described indicates that the power output indication of the remote controlled transmitter has dropped to zero while the video and audio monitors are still functioning normally. This scenario suggests that there is likely no complete failure of the transmitter itself since it can still relay video and audio signals.

The most plausible explanation for the drop to zero in the power output reading, while other functions are operational, can stem from a false reading on the remote control meter. This could occur due to a malfunction or miscalibration of the meter itself, which might not accurately reflect the true power output of the transmitter. If the transmitter is operational enough to transmit video and audio signals, but the meter indicates a power failure, it strongly hints at a problem with the meter rather than with the entire transmission system.

Other options, such as the transmitter being powered off or a malfunction of the aerial, would likely result in a complete failure of video and audio signals, not just the power output reading. Similarly, if the remote control were out of range, you would expect a loss of both monitoring and transmission capabilities, not just an inaccurate power output readout. Therefore, a false reading on the remote control meter aligns best with the observed conditions.