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G9D08
How does a “screwdriver” mobile antenna adjust its feed point impedance?
Pick an answer to check it.
Answer: B. By varying the base loading inductance
A screwdriver antenna uses a motor to move a contact along a base loading coil, varying the loading inductance. This tunes the antenna and adjusts its feed point impedance.
Tip: Screwdriver: motor changes base coil inductance.