LBI-33057
8
ALIGNMENT PROCEDURES
This section outlines alignment procedures for the
UHF RF Board located in the Rear Cover Assembly.
Alignment procedures must be performed in the order
presented to insure proper radio operation. Several test
procedures are presented which will help isolate a prob-
lem if it exists. The circuits in the Front Cover Assembly
contain no adjustments and therefore no alignment is
necessary.
Throughout the service procedures presented
in this manual, the following information
should be observed:
•
The bench power supply should be set for 7.5
±
0.1 Vdc (unless otherwise noted) during
troubleshooting procedures presented in this
manual. If a battery pack is used, it should be
fully charged. Typical battery pack voltage
will be 7.5 Vdc
±
20% over its full discharge
cycle.
•
Logic Levels:
•
Logic 1 = high = greater than 4.5 Vdc Logic 0
= low = less than 0.5 Vdc
•
The modules are not field repairable. Sche-
matics and outline diagrams for the modules
are presented in this manual as a troubleshoot-
ing reference only.
•
The Front Cover Test Accessory Kit allows
the Control Board to be extended out of the
case for troubleshooting access. The LCD and
Keypad circuits can be tested in the case via a
PC computer connection.
•
The personality information stored in the ra-
dio should be backed-up on the PC computer
before any service procedure is performed.
SET-UP PROCEDURE
1. Separate the Front and Rear Cover Assemblies
and connect the RF/Logic Extender cable be-
tween the RF Board and the Control Board. See
Figure 6.
2. Slide the Dummy Battery onto the Front Cover
and connect the audio output leads to the distor-
tion analyzer. Place the Dummy Battery's on/off
switch in the OFF position to direct the speaker
audio to its speakers leads and to the distortion
analyzer. Connect the PC Programmer to the
UDC.
3. Set the power supply to 7.5
±
0.1 Vdc and connect
the Dummy Battery supply leads to the power
supply.
4. Program the radio with the LOW, MIDDLE and
HIGH-side test channels listed in Table 2. To
fully test the transmitter, program a channel pair
for each frequency, one at high-power and one at
low-power. It may be desirable to program more
test channels into the unit.
5. Remove power from the radio and replace the PC
programming cable with the TQ-0609 Test Box.
6. Connect the radio to the wattmeter using the RF
Antenna Adapter. Couple a small amount of the
RF signal to the frequency counter.
LBI-38203 contains detailed information on the
TQ-0609 Test Box.
Table
2 - RF Test Channels
TEST FREQUENCY (MHz)
RF BAND
403-423 MHz
403.025
412.875
422.975
450-470 MHz
450.025
460.025
469.975
470-492 MHz
470.025
480.875
491.975
485-505 MHz
485.0125
500.000
504.9875
492-512 MHz
492.025
501.900
511.975
TRANSMITTER ALIGNMENT
The following information can be used to test and
align the transmitter's output frequency and its modula-
tion characteristics. Completion of these tests/alignments
will verify a near 100% operating synthesizer and
transmitter stages.
SERVICE NOTES
NOTE
