Basic Qualification · B-006 Feedlines and antenna systems · B-006-004-003
If your transmitter and antenna are 15 metres apart, but are connected by 60 metres of RG-58 coaxial cable, what should be done to reduce transmission line loss?
- AInstall a balun at the antenna feed point
- BRoll the excess cable into a coil
- CInstall a low-pass filter at the transceiver
- DShorten the excess cable
Correct answer: D — Shorten the excess cable. From the official ISED question bank, verified word for word.
Why
Coaxial cable absorbs some of your radio signal as heat, and this loss grows longer the more cable you use. The full explanation — and one for every question — is in Pro.
Practise this section
Feedlines and antenna systems is section B-006 of the Basic exam: Getting the signal out: antennas, feedlines, SWR, baluns, matching, and why antenna length depends on frequency.
Drill B-006 — free, no account