| 摘要 |
<p>The low profile V.H.F. antenna consists of a shunt-fed monopole (10) with a top loading consisting of a multi-turn helical loop (13). Switches (22, 23) within the loop are actuated by solenoids (26, 27) respectively in the base (11) of the antenna for waveband selection. A motor driven variable capacitor (16) is connected to the whole or part of the loop, in dependence on switches (22, 23) for turning the antenna. The switches are positioned within the loop and are actuated via insulating rods by the solenoids axially spaced from the loop. Both the motor and the capacitor are axially spaced from the loop.</p> |
