Advanced Qualification · A-005 Transmitters, modulation and processing · A-005-006-002
How does intermodulation interference between two repeater transmitters usually occur?
- AWhen they are in close proximity and the signals cause feedback in one or both of their final amplifiers
- BWhen the signals are reflected out of phase by aircraft passing overhead
- CWhen they are in close proximity and the signals mix in one or both of their final amplifiers
- DWhen the signals are reflected in phase by aircraft passing overhead
Correct answer: C — When they are in close proximity and the signals mix in one or both of their final amplifiers. From the official ISED question bank, verified word for word.
Why
Intermodulation happens when two strong transmitters sit close together, causing their radio waves to enter the final amplifier of one unit. The full explanation — and one for every question — is in Pro.
Practise this section
Transmitters, modulation and processing is section A-005 of the Advanced exam: Transmitters, modulation and processing: AM, FM, SSB, keying, speech processing, and the numbers behind occupied bandwidth.
Drill A-005 — free, no account