The MF/HF transceiver produces strong AF...

The MF/HF transceiver produces strong AF...

Question 1 of 27070QQKlDnMRVPfYR0nvLc1I

The MF/HF transceiver produces strong AF output but no signals are heard on any frequency. What is the most likely cause?

Question 1 of 27070

Q

The MF/HF transceiver produces strong AF output but no signals are heard on any frequency. What is the most likely cause?

🔍 Key Concepts

• MF/HF radiotelephone receiver signal path: RF/IF stages, detector, then AF (audio frequency) amplifier • Difference between no RF received vs. no audio out conditions • Effect of squelch and antenna/feeder line faults on what you hear in the speaker

💭 Think About

• If you have strong AF output in the speaker, what does that tell you about the condition of the AF amplifier stages? • What kind of fault would cause there to be no received signals on any frequency, but still allow you to hear loud audio noise from the speaker? • In which part of the receiver would a failure prevent RF from ever reaching the detector, even though the audio stages are fine?

✅ Before You Answer

• Confirm what "strong AF output" implies about where the fault is not located • Consider whether a completely open transmission line to the antenna would still allow you to hear any internal noise in the receiver • Distinguish carefully between failures in audio (AF) stages and failures in earlier RF/IF or power amplifier stages of the receiver