CHAPTER 3
TROUBLESHOOTING
Section I. GENERAL
shooting of the measurement systems and of the signal
3-1. Purpose
source.
When a malfunction is attributed to a
Troubleshooting is a systematic isolation of malfunctions
commercial equipment, the appropriate technical or
and defective components by observation of symptoms
commercial manual is referenced as a corrective
and tests. The tests and corrective measures provided
measure. Section III contains troubleshooting test charts
herein are governed by the scope of the level of
for the rf heads of the signal source, along with complete
maintenance.
schematic diagrams, parts lists, and a resistance check
chart.
3-2. Contents
Section II provides operational checks and trouble-
Section II. OPERATIONALCHECKS AND TROUBLESHOOTING OF
SYSTEM MEASUREMENT SETUPS
the "Normal indication" column, proceed with the next
3-3. General
step until an abnormal indication is observed. When this
a.
Content.
This section provides combined
occurs, note the entry in the "Possible cause of
operational check and troubleshooting test charts for the
malfunction" column and perform the instructions listed
frequency, power, magnitude of reflection coefficient,
in the "Corrective measure" column. After correction of
VSWR, and attenuation measurement systems. These
malfunction, repeat the complete procedure starting with
charts help to detect, locate and correct malfunctions
the first step.
that may occur when performing the above-mentioned
3-4. Operational Check and Troubleshooting
measurements.
Settings or manipulation of test
equipment controls and the normal observable condition
of Frequency Measurement Setups
of test equipment indication is included for each step.
for an Active Source Below 15 GHz.
Possible causes for abnormal indications, as well as
a. Preliminary Procedure.
authorized corrective measures, are also included for
(1) Set up equipment as shown in the figure
each step. A thorough knowledge of the applicable
illustrating setups for frequency measurement of an
operating procedures given in TM 9-4931-294-15/1,
active source below 15 GHz in chapter 2, section III, of
TM 9-4931-294-15/1. (2) Set level-set attenuator for
checks.
maximum attenuation.
b. Procedure. Before proceeding with the steps of
(3) Set controls of digital counter and frequency
the charts, be sure that the preliminary instructions
converter as follows:
preceding the chart have been observed. When using
the charts, perform he operations listed under the
Control
Position
"Procedure" column for the first step and note the
POWER
OFF
indications obtained on the equipment. If the indications
TIME BASE
Setting appropriate for
obtained
correspond
with
those
listed
in
frequency being measured
3-1
