The phase locked loop circuit in an MF/HF...

Question 1 / 27070nbKD9ByGoJa8vkfMaazm

Question 1 of 27070nbKD9ByGoJa8vkfMaazm

The phase locked loop circuit in an MF/HF receiver appears to be faulty. What is the most likely cause?

Question 1 of 27070

The phase locked loop circuit in an MF/HF receiver appears to be faulty. What is the most likely cause?

🔍 Key Concepts

• Phase-Locked Loop (PLL): how it keeps a local oscillator locked to a reference frequency • Role of a Voltage Controlled Oscillator (VCO) inside a PLL • Difference between circuits that affect detection (BFO, filters, AGC) vs circuits that control tuning/locking

💭 Think About

• In a PLL, which single sub‑circuit actually changes frequency in response to a control voltage? • Which of the listed options is an essential internal part of a PLL, rather than a separate function like filtering or audio control? • If a receiver cannot stay locked on frequency, which type of component failure would most directly cause loss of lock?

✅ Before You Answer

• Identify which choice is the core tunable element in a PLL • Confirm which items (AGC, BFO, I.F. filter) mainly affect signal level or demodulation, not frequency locking • Make sure the option you pick is something that exists inside the PLL loop rather than elsewhere in the receiver

Question 1 of 27070

The phase locked loop circuit in an MF/HF receiver appears to be faulty. What is the most likely cause?

The AGC circuit has become defective.

The Beat Frequency Oscillator is inoperative.

The Voltage Controlled Oscillator is inoperative.

The 500 Hz I.F. filter has become defective.

Question 1 / 27070nbKD9ByGoJa8vkfMaazm

Question 1 of 27070nbKD9ByGoJa8vkfMaazm

The phase locked loop circuit in an MF/HF receiver appears to be faulty. What is the most likely cause?

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Question 1 of 27070

The phase locked loop circuit in an MF/HF receiver appears to be faulty. What is the most likely cause?