The Basic lessons · Feedlines and antenna systems · B-006-008

Tuning Antennas: Length, Speed, and Traps

Learn how changing an antenna's length or adding components shifts its resonant frequency. Understand the speed of radio waves and how to calculate wavelength in free space.

This lesson is part of SignalPrep Pro. The subsection's 11 exam questions are free to practise: practise B-006-008.

What this subsection asks

• A wire dipole has a resonant frequency of 3900 kHz. How can you change its resonant frequency to 3600 kHz?
• A wire dipole has a resonant frequency of 3600 kHz. How can you change its resonant frequency to 3900 kHz?
• What is the wavelength in free space of a 25 MHz signal?
• The velocity of propagation of radio frequency energy in free space is:
• Adding a series inductance to an antenna would:
• The resonant frequency of an antenna may be increased by:
• The speed of a radio wave:
• Why are insulators used at the ends of a suspended wire antenna?
• To lower the resonant frequency of an antenna, the operator should:
• Some antennas are constructed with traps. What is a trap?
• What is the wavelength in free space of a 2 MHz signal?