User's Manual

300-Watt UHF Digital Transmitter Chapter 1, Introduction
DT830A, Rev. 1 1-2
Ventilation – Openings in the cabinets
and tray front panels are provided for
ventilation. To ensure reliable operation,
and to protect the unit from overheating,
these openings must not be blocked.
Servicing – Do not attempt to service
this product until becoming familiar with
the equipment. If in doubt, refer all
servicing questions to qualified Axcera
service personnel.
Replacement Parts – When
replacement parts are used, be sure that
the parts have the same functional and
performance characteristics as the
original part. Unauthorized substitutions
may result in fire, electric shock, or other
hazards. Please contact the Axcera
Technical Service Department if you have
any questions regarding service or
replacement parts.
Caution: Because the capacitors
used in the high-voltage circuits
have the potential of recharging
themselves, care must be taken
when handling them. The capacitors
should first be shorted with a
grounding stick and then a piece of
wire should be connected across the
terminals until they can be put into
service. Remember to remove the
shorting wire before energizing the
high-voltage supply.
1.4 Maintenance
The DT830A is designed with
components that require little or no
periodic maintenance except for the
routine cleaning of the fans and the front
panels of the trays.
The amount and time interval between
cleanings depends on the conditions
within the transmitter room. While the
electronics have been designed to
function even if covered with dust, a
heavy buildup of dust, dirt, or insects will
hinder the effectiveness of the cooling of
the components. This could lead to a
thermal shutdown or the premature
failure of the affected trays.
When the front panels of the trays
become dust covered, the top covers
should be removed and any accumulated
foreign material should be removed. A
vacuum cleaner, utilizing a small, wand-
type attachment, is an excellent way to
suction out the dirt. Alcohol and other
cleaning agents should not be used
unless you are certain that the solvents
will not damage components or the silk-
screened markings on the trays and
boards. Water-based cleaners can be
used, but do not saturate the
components. The fans and heatsinks
should be cleaned of all dust or dirt to
permit the free flow of air for cooling
purposes.
It is recommended that the operating
parameters of the transmitter be
recorded from the meters on the trays
and the system metering control panel at
least once a month. It is suggested that
this data be retained in a rugged folder
or envelope for the life of the equipment.
A sample format for a log sheet is
provided in Appendix A. Photocopies of
the log sheet should be made for future
data entries.
1.5 Material Return Procedure
To insure the efficient handling of
equipment or components that have been
returned for repair, Axcera requests that
each returned item be accompanied by a
Material Return Authorization Number
(MRA#).
An MRA# can be obtained from any
Axcera field service engineer by calling
the Axcera Field Service Department at
[phone]. This procedure applies
to all items sent to the Field Service
Department regardless of whether the
item was originally manufactured by
Axcera.