What is the purpose of Automatic Frequency Control (AFC)?

Automatic Frequency Control (AFC) is a system used to automatically adjust the frequency of a receiver to match the frequency of the incoming signal. This is particularly important in communication systems where maintaining the accuracy of the frequency can be crucial for effective signal processing. The main purpose of AFC is to ensure that the receiver is tuned to the correct frequency, which can help prevent issues such as drift due to temperature changes or other environmental factors.

In this context, stating that AFC keeps the frequency 30 MHz above the transmitter frequency implies a specific function of the system that ensures the receiver is locked onto the desired signal for optimal reception and clarity. The prevention of drift thus allows for a consistent and reliable communication link necessary for the operation of radar systems.

The other choices do not encapsulate the primary function of AFC. For example, displaying signal strength pertains to a different aspect of signal processing; stabilizing gain refers to handling the amplification of signals rather than frequency adjustments. Measuring signal interference is more aligned with analyzing the quality of the signal rather than tuning it to the correct frequency. Therefore, the fundamental role of AFC remains focused on frequency management to ensure accurate transmission and reception within communication systems.