Question T4B12 about the function of automatic gain control was added to this section…Dan
To properly operate a transceiver, you need to know how to use the controls. Perhaps the most important transmitter control is microphone gain. If a transmitter is operated with the microphone gain set too high, the output signal might become distorted. (T4B01)
You also need to know how to set the operating frequency of your transceiver. The keypad or VFO knob can be used to enter the operating frequency on a modern transceiver. (T4B02) A way to enable quick access to a favorite frequency on your transceiver is to store the frequency in a memory channel. (T4B04)
A common receiver control on VHF/UHF transceivers is the squelch control. The purpose of the squelch control on a transceiver is to mute receiver output noise when no signal is being received. (T4B03) If set too high, then you will not be able to hear low-level signals.
Another common setting on VHF/UHF transceivers is the offset frequency. This is especially important when operating repeaters. The common meaning of the term “repeater offset” is the difference between the repeater’s transmit and receive frequencies. (T4B11)
A common receiver control on HF transceivers is the RIT control. The term “RIT” means Receiver Incremental Tuning. (T4B07) The receiver RIT or clarifier are controls that could be used if the voice pitch of a single-sideband signal seems too high or low. (T4B06)
Another common control on a receiver is the automatic gain control, or AGC. Its function is to keep received audio relatively constant. (T4B12) This is important because HF signal strengths can vary widely. and that can cause audio levels to vary widely as well.
HF transceivers are often equipped with a variety of different filters. The advantage of having multiple receive bandwidth choices on a multimode transceiver is that it permits noise or interference reduction by selecting a bandwidth matching the mode. (T4B08) For example, 2400 Hz is an appropriate receive filter to select in order to minimize noise and interference for SSB reception. (T4B09) 500 Hz is an appropriate receive filter to select in order to minimize noise and interference for CW reception. (T4B10)