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T9B - Antennas and feed lines

Technician Class

Feed lines: types, attenuation vs frequency, selecting; SWR concepts; Antenna tuners (couplers); RF Connectors: selecting, weather protection

12 questions | Updated: Feb 19, 2026

All T0A T0B T0C T1A T1B T1C T1D T1E T1F T2A T2B T2C T3A T3B T3C T4A T4B T5A T5B T5C T5D T6A T6B T6C T6D T7A T7B T7C T7D T8A T8B T8C T8D T9A T9B
T9B01

Which of the following connectors should be carefully taped for weather protection when used outdoors?
T9B02

What is the most common impedance of coaxial cables used in amateur radio?
T9B03

Why is coaxial cable the most common feed line for amateur radio antenna systems?
T9B04

What is the major function of an antenna tuner (antenna coupler)?
T9B05

What happens as the frequency of a signal in coaxial cable is increased?
T9B06

Which of the following connector types is most suitable as an RF connector for frequencies above 400 MHz?
T9B07

Which of the following is true of PL-259 type coax connectors?
T9B08

Which of the following is a source of loss in coaxial feed line?
T9B09

What can cause erratic changes in SWR?
T9B10

What is the electrical difference between RG-58 and RG-213 coaxial cable?
T9B11

Which of the following types of feed line has the lowest loss?
T9B12

What is standing wave ratio (SWR)?