Advanced Qualification · A-005 Transmitters, modulation and processing · A-005-006-007
Which type of filter would be best to use in a 2-metre repeater duplexer?
- AA cavity filter
- BA DSP filter
- CAn L-C filter
- DA crystal filter
Correct answer: A — A cavity filter. From the official ISED question bank, verified word for word.
Why
A cavity filter is the best choice for a 2-metre repeater duplexer because it uses a hollow metal chamber to block unwanted signals while letting the desired frequency pass with very little loss, which is essential when transmitting and receiving at the same time. 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