🔍 Key Concepts

• Difference between receiver tuning and antenna tuning on MF/HF radios • How an automatic antenna tuner (ATU) works when you press a tune function • What parts of the radio actually change when you select an ITU channel vs when you press TUNE

💭 Think About

• When you change the ITU channel, what is already being adjusted automatically inside the radio? So what extra task would a separate TUNE button be needed for? • During transmission on MF/HF, what needs to be properly matched so maximum power can be radiated and the transmitter is protected? • Does the TUNE function affect what you hear (audio), what frequency you are on, or how efficiently your signal gets out through the antenna?

✅ Before You Answer

• Distinguish between channel selection functions and tuning functions on the front panel • Recall that MF/HF sets normally have a separate unit or circuit to match transmitter output to the antenna • Check which option refers to something that happens on the transmit side, not just in the audio or receive stages