Advanced Qualification · A-005 Transmitters, modulation and processing · A-005-003-001
In a simple 2 stage CW transmitter circuit, the oscillator stage and the class C amplifier stage are inductively coupled by a RF transformer. Another role of the RF transformer is to:
- A provide the necessary feedback for oscillation
- B act as part of a balanced mixer
- C be part of a tuned circuit
- D act as part of a pi filter
Correct answer: C — be part of a tuned circuit. From the official ISED question bank, verified word for word.
Why
In a simple two-stage CW transmitter, the RF transformer linking the oscillator and amplifier does more than just pass energy; its coils form a tuned circuit that selects the desired frequency and rejects others. The full explanation — and one for every question — is in Pro.
Practise this section
Transmitters, modulation and processing: AM, FM, SSB, keying, speech processing, and the numbers behind occupied bandwidth.