Vertex Standard VX-5500V Service Manual page 23

Alignment
Before beginning, connect the transceiver and PC
using the CT-71 programming cable, and download
the EEPROM data from the transceiver to the com-
puter.
Store this data in a disk file so that it can be saved
and retrieved later. Using the table below, program
the channel, CTCSS, and DCS alignment settings for
your transceiver version. Upload this file to the
transceiver.
Note:Signal levels in dB referred to in this proce-
dure are based on 0 dBµ = 0.5 µV (closed cir-
cuit).
Caution:Do not connect the audio output line to
ground, and be certain that the speaker has
adequate capability to handle the audio
output from the radio.
Because of the bridge audio amplifier cir-
cuit used in the radio, it is necessary to con-
struct and use a simple audio load test
adapter as shown in the schematic diagram
below, when conducting receiver align-
ment steps.
3.5 PLUG
2-ohm
10W
2-ohm
10W
(4-ohm Dummy Load)
AF Test Adapter Schematic
Alignment Channel Frequencies
Frequency
Channel
(simplex)
CH1 148.01 MHz
CH2 161.01 MHz
CH3 173.99 MHz
CH4 148.01 MHz
CH5 161.01 MHz
CH6 173.99 MHz
CH7 161.01 MHz 151.4 Hz
CH8 161.01 MHz
CH9 161.01 MHz 151.4 Hz
CH10 161.01 MHz
5-2
Attenuated
Test Output(1/2)
GND
470uF
CTCSS DCS
Narrow/Wide
Encode Encode
None None Wide
None None Wide
None None Wide
None None Narrow
None None Narrow
None None Narrow
None Wide
None 023 Wide
None Narrow
None 023 Narrow
PLL & Transmitter
Set up the test equipment as shown for transmit-
ter alignment.
Maintain the supply voltage at 13.8 V DC for all
steps.
50-Ohm
Dummy Load
Inline Wattmeter
RF Sampling
Deviation Meter
Coupler
CT-71 connection
Cable
Frequency
Counter
PLL VCV
r Connect the positive lead of the DC voltmeter to
test point TP1008 (VCV) on the Main Unit, as in-
dicated in the figure, and connect the negative
lead to chassis ground.
r Set the transceiver to the high band edge fre-
quency channel (CH3 or CH6), then key the trans-
mitter, and adjust L1026 on the Main Unit for 4.3
V ±0.1 V on the voltmeter.
r Adjust L1023 on the Main Unit for 4.3 V ±0.1 V
on the voltmeter.
r Next select to the low edge frequency channel
(CH1 or CH4) and confirm the VCV is more than
1.0 V on the voltmeter.
r Key the transmitter, and confirm the VCV is more
than 1.0 V on the voltmeter.
PLL Reference Frequency
With the wattmeter, dummy load and frequency
counter connected to the antenna jack, and select
band center frequency channel (CH2 or CH5), key
the transmitter and adjust VR1001 on the Main Unit,
if necessary, so the counter frequency is within 100
Hz of the channel center frequency for the trans-
ceiver version.
RF Signal
Generator
Transceiver
Power Supply
PC
13.8V DC
COM port