Practical_Antenna_Handbook_0071639586

392 P a r t V : H i g h - F r e q u e n c y A n t e n n a s f o r S p e c i a l i z e d U s e s
Optional capacitive
top hat
Less than 4
L
Coax to
transmitter
Radials: 246
4 F(MHz)
Antenna
tuner
Three or more
4
Radials
Figure 17.1A Radials can enhance a basic mobile antenna system at a fixed location.
Figure 17.1B shows a workable system that will further improve the performance of
a mobile rig in stationary situations. The mobile antenna uses the normal base mount
attached to the rear quarter-panel of the car adjacent to the trunk lid. An all-metal
grounding-type binding post is installed through an extra hole drilled in the base insulator
(see Fig. 17.1C). Radials for portable operation are attached at this point. The binding
post should be sized to easily accommodate three or four #18 radials. In a pinch,
additional radials can be attached to the base indirectly by connecting them to the top
of one or more of the radials already on the binding post.