Basic Qualification · B-006 Feedlines and antenna systems · B-006-004-006
Assuming the same transmitter and RF output power are used, what is the effect of changing the transmission line from RG- 213 coaxial cable to RG-58?
- A More RF power is radiated from the antenna
- B SWR at the transmitter increases
- C SWR at the transmitter decreases
- D Less RF power is radiated from the antenna
Correct answer: D — Less RF power is radiated from the antenna. From the official ISED question bank, verified word for word.
Why
RG-58 coaxial cable has a thinner centre conductor than RG-213, which causes it to lose more energy as heat when carrying radio frequency signals. The full explanation — and one for every question — is in Pro.
Practise this section
Getting the signal out: antennas, feedlines, SWR, baluns, matching, and why antenna length depends on frequency.