[KYHAM] KEN Text for April 8: Mobile Installation Issues

[Ron Dodson]

Spring brings numerous chores and things to do into one's
mind.  Spring also means another year of VHF/UHF roving,
storm spotting and family trips in the car.  Lots of
opportunities for mobile amateur radio contesting, public
service work and adventure!  How's your mobile doing after
the winter season?  Are you buying a new rig at one of the
local hamfests or Dayton this year?  Here is a reprint of
the material from our friend Tony on mobile radio
installations.

73,
Ron, KA4MAP


Ky Emergency Net Text for: April 8,
Mobile Installation Issues
By A. Whobrey, KC4JTV

Mobile radio is one of the most useful tools in any radio
operators
arsenal, amateur or commercial. The ability of mobile units
to provide
immediate, on the spot communications makes them desirable
to all types
of radio users. There are many mobile units in use today,
with a wide
variety of installation methods, both good and not so good.
Proper
attention to installation will help you get maximum service
and
enjoyment from your mobile station.

 Placement of the radio in your vehicle is nearly always a
compromise,
with a number of factors involved. The radio must be
securely mounted
and easily accessible, with the display visible for
convenient
operation. At the same time, it must not interfere with the
operation of
any of your auto�s other controls. If your vehicle has
airbags, keep all
equipment well clear of their deployment zone. I have seen
many
installations where the radio was merely jammed or wedged
between the
operator�s seat and a console, resist the temptation to do
this. This
type of  �mounting� guarantees that if you are involved in
even a minor
accident or �off road excursion� this winter, your radio
will be lying
in the vehicle floor, useless.

 Except for temporary installations, avoid magnet mounted
antennas. Even
the best magnet mount will eventually cause damage to your
car�s finish.
Use of a magnet mount also makes coax damage likely, due to
a trunk lid
or door repeatedly closing on the exposed cable. With the
widespread use
of cellular phone service today, that 3/8� or 3/4� hole
won�t affect the
resale value of your car as much as you imagine. Public
safety users
have known for years that the hole (or permanent) mount is
the way to
go, using a rooftop or trunk lid location. This mounting
method puts the
entire coax inside the car, where it will be protected from
weather and
physical damage. Generally speaking, hole mounts will be
supplied with a
higher quality coax cable, since they are marketed for
commercial  and
public safety applications. A properly mounted antenna will
greatly
increase the dependability of your mobile station.

 Power leads are another common weak point in mobile
installation,
appearances here can be deceiving. Don�t be mislead because
the radio
lights up and appears to work properly, if your power
connection fails,
you are off the air. Power leads should be run to the
vehicle�s battery
and must be of  large enough gauge to insure full voltage to
the
transceiver. Fuse the �hot� lead(s) as close to the battery
as possible,
in any case before the wire enters a passenger compartment.
Under hood
wiring should be properly secured and protected from sharp
or hot
surfaces. Ground wire(s) should be terminated with a ring
type terminal,
not merely wrapped under a convenient screw head. Remove
paint from the
immediate area, and use star washers to secure the
connection.

 Probably the most over looked detail in non-commercial
mobile
installation is the microphone hanger.  Even if you will
leave a couple
of small holes in your dashboard, a well placed mic hanger
is a good
investment toward operating ease. Find a handy place for
your mic, so
that it can be easily located while driving. After all, the
microphone
is the most commonly used �control� in mobile operation.