Jensen VR209 Marine Radio User Manual


 
VR209
16
CARE AND MAINTENANCE
Keep the product dry. If it does get wet, wipe it dry immediately. Liquids might contain
minerals that can corrode the electronic circuits.
Keep the product away from dust and dirt, which can cause premature wear of parts.
Handle the product gently and carefully. Dropping it can damage circuit boards and
cases, and can cause the product to work improperly.
Wipe the product with a dampened cloth occasionally to keep it looking new. Do not use
harsh chemicals, cleaning solvents, or strong detergents to clean the product.
Use and store the product only in normal temperature environments. High temperature
can shorten the life of electronic devices, damage batteries, and distort or melt plastic
parts.
Ignition
The most common source of noise in reception is the ignition system. This is often a result of
the radio being placed relatively close to the ignition system (engine). This type of noise can be
easily detected because it will vary in intensity of pitch with the speed of the engine.
Usually, the ignition noise can be suppressed considerably by using a radio suppression type
high voltage ignition wire and suppressor resistor in the ignition system. (Most vehicles employ
this wire and resistor, but it may be necessary to check them for correct operation.) Another
method of suppression is the use of additional noise suppressors. These can be obtained from
most CB/A radio or electronic supply shops.
Interference
Radio reception in a moving environment (automobile) is very different from reception in a
stationary (home) environment. AM reception will deteriorate when passing through a tunnel or
when passing under high voltage lines. Noise can be picked up from passing automobiles.
Although AM is subject to environmental noise, it can received at great distances. This is
because broadcasting signals follow the curvature of the earth and are reflected back by the
upper atmosphere.