Antenna System - Midland M Zero Manual Del Usaurio

ANTENNA SYSTEM

A mobile antenna system is not limited only to the antenna. The transmis-
sion line as well as the vehicle are important factors in the total antenna
system. Therefore, you must use the correct type of transmission line and
mount the antenna securely in a position that will give you optimal re-
sults. Use coaxial cable with an impedance of 50 Ohms. We suggest type
RG 58/U for lengths under 2.5 m or RG 8/U for longer lengths. Generally
speaking, you should keep the length of the transmission line to a mi-
nimum. The above discussion is as important for reception as for the
transmission. If a mismatch exists between the antenna and the receiver,
the excellent sensitivity and signal-to-noise radio of the receiver circuit
will be defeated.
Suggestions
A few general rules should help you to install any mobile antenna pro-
perly.
• Keep it as far as possible from the main bulk of the vehicle.
• During operation, it must be vertical, and rigid enough to remain ver-
tical when the vehicle or boat is in motion.
• Mount it as far as possible from sources of noise (ignition system,
gauges, etc.) and keep the transmission line away from these noise
sources.
• An antenna mounted in a boat requires a good ground connection.
This can be either a metal hull or a ground made of tin-foil or copper
sheeting.
This ground should cover an area of at least 1 m2 or more. Be sure the
transceiver also has an adequate ground. There are many types of mobile
CB antennas: a full quarter-wave length whip, a centerloaded whip, top
loaded whip and the base loaded type are typical. A vertically polarized
whip antenna is best suited for mobile service. It is omnidirectional. If it's
the loaded type, you will find it a physically shorter antenna. But, for gre-
ater efficiency the 2.5 m long, full quarter-wave whip is better. Antenna
length is directly related to efficiency.
Generally, the longer it is, the more efficient will be.
There are many possible antenna locations on a car.
Four of the most popular are shown and discussed on the following.
Roof Mount
In this position the antenna radiates equally in all directions. Since the
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