Basic Qualification · B-008 Interference and suppression · B-008-003-005
In Morse code transmission, local RF interference (key clicks) is produced by:
- Apoor wave-shaping caused by a defective filter capacitor
- Bthe making and breaking of the circuit the Morse key
- Cfrequency shifting caused by poor voltage regulation
- Dhigh frequency parasitic oscillations
Correct answer: B — the making and breaking of the circuit the Morse key. From the official ISED question bank, verified word for word.
Why
When you press or release a Morse key, you instantly connect or disconnect the radio's power circuit. The full explanation — and one for every question — is in Pro.
Practise this section
Interference and suppression is section B-008 of the Basic exam: When things interfere: harmonics, overload, RFI to and from your station, filters, ferrites and how to fix the neighbour's TV.
Drill B-008 — free, no account