Basic Qualification · B-003 Station assembly, practice and safety · B-003-007-005
Why are isolation transformers often included in the sound card interface of a station operating computer-based digital modes?
- A To prevent the coupling of the transceiver and computer from introducing hum and interference into
- B To increase the signal voltage generated by the computer to the level required by the transceiver
- C To match the impedance of the computer output signal to the impedance of the input of the computer
- D To provide a source of DC power for the circuitry in the interface
Correct answer: A — To prevent the coupling of the transceiver and computer from introducing hum and interference into. From the official ISED question bank, verified word for word.
Why
Isolation transformers break the direct electrical path between your computer and radio, stopping unwanted ground loops that cause annoying hum and interference in your audio signals. The full explanation — and one for every question — is in Pro.
Practise this section
Building a station safely: power supplies, grounding, RF exposure, lightning, feedline routing, and what a transmitter, receiver and transceiver actually do.