Service manual
ALIGNMENT PROCEDURE AND PERFORMANCE TESTS
7-4
April 2001
Part No. 001-9800-203
7.3 ADJUSTMENT PROCEDURE
7.3.1 PRELIMINARY
The following adjustments are made with the
computer and RPI connected to the transceiver as
described in Section 7.1. Proceed as follows:
1. Connect this test setup described in Section 7.1.3,
turn transceiver power on, and start the Tune
program as described in Section 7.2.3.
2. The opening screen shown in Figure 7-2 is then
displayed. From this screen select “Tune Radio” to
automatically go from one adjustment to the next, or
select the adjustments one at a time.
7.3.2 FREQUENCY AND BIAS ADJUSTMENT
1. Remove the top cover to access the RF board.
Connect a 50-ohm load to the antenna jack and
monitor the transmit frequency with a communica-
tion monitor.
2. Manually select “TCXO Frequency Adjustment” or
automatically select “Reference Frequency
Adjustment”.
3. Manually adjust the variable capacitor in reference
oscillator U806 for the displayed frequency ±100
Hz (see Figure 7-4).
4. With UHF 470-512 MHz models only, connect a DC
voltmeter to the junction of L505 and C529 (see
following illustration). Then adjust R527 for a meter
reading of 3.00 volts (with transmitter keyed).
UHF 470-512 MHz Adjustment Points
7.3.3 MODULATION PEAK FREQUENCY
(UHF MODELS ONLY)
1. Manually select “Peak Modulation Frequency” or
automatically select “Tune Modulation Peak
Frequency”.
2. Apply a 1 kHz, 1 volt rms, AC coupled signal to the
transmit audio input jack of the RPI as shown in
Figure 7-1.
3. Monitor the transmit modulation signal with a
communications monitor. If applicable, set the
monitor high-pass filter for 50 kHz and the low-pass
filter for 15 kHz.
4. Follow the instructions on the screen to select the
frequency with the highest deviation. Remove the
1 kHz injection signal.
7.3.4 POWER OUTPUT
This adjustment sets the power output selected by
the power output setting programmed for each system.
With low tier models, high and low settings are avail-
able, and with high tier models, high, low 1, low 2,
low 3, and low 4 setting are available.
1. Connect a wattmeter and antenna load to the
antenna jack as shown in Figure 7-1.
2. Manually select “Power Output” or automatically
select “High Power Output”.
3. Follow the instructions on the screen and set the
High Power Level on the low and high channels for
a value within the range which follows (both chan-
nels must be set the same).
Model* Power Setting Range
25 Watt UHF 2-25 Watts
40 Watt UHF 10-40 Watts
15 Watt 800/900 MHz 2-15 Watts
30 Watt 800/900 MHz 10-30 Watts
* The transceiver power output is indicated by the fifth
digit of the transceiver identification (serial) number
as follows: 0/1/4/6/8 = 15 or 25W, 2/3/5/7/9 = 30 or
40W (see Section 1.4).
EP3
L506
C5
5
C538
C559
C558
C539
R537
C5
3
C557
C580
L505
C529
R528
R527
C528
R532
C525
C524
C
R83
L80
0
Q8
0
R
8
Q
8
C
CR800
C808
C807
C817
C813
C522
R530
L503
C552
C550
L504
R531
R529
C518
C553
R535
L501
C555
C556
R533R536
C51
7
C541
Q510
L502
C551
C523
C521
C526
C527
C530
C531
C542
Q506
R522
C543
Q511
R534
C544
C511
EP2
C514
C515
C516
R847
R830
Q507
C540
R523 R844
R521
R833
C826
L801
C822
R827
CR801
Q509
1
C
B
EC
E
B
E
C
B
E
G
D
S
C
C
B
B
E
E
B
B
B
R527 L505/C529