Vector-LP Radio Beacon Transmitter Technical Instruction Manual
Page
4-1
Section 4 Testing and Adjustment
Issue 1.1
Vector-LP Radio Beacon Transmitter
TECHNICAL INSTRUCTION MANUAL
Section 4
TESTING AND ADJUSTMENT
4.1 INTRODUCTION
This section contains step-by-step
functional test procedures using integral
meters and precision test/monitoring
equipment. The test procedures contain
routine adjustment instructions to bring the
parameter being tested within defined
limits, where appropriate.
NOTE
Nautel recommends all instructions be
followed in the order presented, particularly
by personnel who are not familiar with
detailed circuit theory and may not realize
the impact a specific adjustment can have
on other steps. These adjustments should
be performed during initial turn-on and after
major repairs or a frequency change.
4.2 OPERATING PRECAUTIONS
The transmitter contains protection circuits
that monitor critical parameters. When the
defined limits of any of these parameters
are exceeded, one of the operational lamps
on the exciter panel’s system diagram will
turn red. If the alarm condition could result
in excessive power amplifier stress current,
the control voltage applied to the power
amplifiers will effectively be reduced or
turned off until the out-of-tolerance
condition no longer exists. Maintainers
should read and fully understand the
Section 3 - Operating Instructions, and in
particular the section on controls and
indicators.
NOTE
The diagnostic display’s meters screen
displays three pre-determined parameters
(e.g., forward power, total dc current, +15 V
power supply, etc.). All transmitter
parameters may be displayed on this
screen. See paragraph 3.6.8.1.
4.3 FUNCTIONAL TESTS
To verify the transmitter circuits are within
factory specifications, complete the tests in
this section. In cases where a routine
adjustment will correct an out-of-tolerance
condition, the adjustment procedure is
included.
NOTE
If an in-tolerance condition cannot be
attained with the specified routine
adjustment, discontinue testing until the
cause of the out-of-tolerance condition is
corrected.
4.3.1 General
Functional tests should be performed as a
routine part of scheduled maintenance
checks, and as the first step in
troubleshooting procedures. The results
should be recorded for comparison with
past and future test results.
4.3.1.1
The functional test procedures are
provided in a step-by-step format. This
method of presentation will permit a person
who is unfamiliar with the transmitter to
perform the functional tests in a logical
sequence. The procedures should be
completed in sequence, as each procedure
establishes switch settings and contains
prerequisites for subsequent procedures.
4.3.1.2
The following assumes the initial
turn-on procedure detailed in Section 2 has
been completed during initial installation,
and after major repairs that warrant the
initial start-up procedure be repeated.
