Detuning in the field is caused by which factors?

• A. Nearby objects, temperature, and weather.
• B. Power supply voltage only.
• C. Antenna color.
• D. Operator experience.

Answer: (A)

Detuning in the field happens when the antenna system’s impedance changes because of its surroundings and conditions. Nearby objects can couple energy to or from the antenna, effectively changing its electrical length and the resonance point, which shifts the frequency where the antenna is most efficient and alters the standing-wave ratio. Temperature makes components drift; the tuning network’s capacitors and inductors can change value with heat or cold, and even the physical dimensions of conductors can expand or contract, nudging the resonance. Weather brings moisture and varying dielectric loading around the antenna and insulators, plus rain or wind can subtly move parts or alter the antenna environment, all of which change impedance and detune the system. So detuning in the field is caused by nearby objects, temperature, and weather, rather than by power supply voltage alone, antenna color, or operator experience.