Basic Qualification · B-008 Interference and suppression · B-008-003-011
Transmitter RF amplifiers can generate parasitic oscillations:
- A above or below the transmitter frequency
- B on VHF frequencies only
- C on the transmitter fundamental frequency
- D on harmonics of the transmitter frequency
Correct answer: A — above or below the transmitter frequency. From the official ISED question bank, verified word for word.
Why
Parasitic oscillations are unwanted signals that an amplifier creates on its own, often at frequencies much higher or lower than the one you intend to transmit. The full explanation — and one for every question — is in Pro.
Practise this section
When things interfere: harmonics, overload, RFI to and from your station, filters, ferrites and how to fix the neighbour's TV.