Yaesu VX-4000 Series User manual

Alignment
The VX-4000 has been carefully aligned at the factory
for the specified performance across the frequency range
specified for each version.
Realignment should therefore not be necessary except
in the event of a component failure, or alteration of
version. All component replacement and service should
be performed only by an authorized Yaesu representative,
or the warranty policy may be voided.
The following procedures cover the sometimes critical
and tedious adjustments that are not normally required
once the transceiver has left the factory. However, if
damage occurs and some parts are replaced,
realignment may be required. If a sudden problem occurs
during normal operation, it is likely due to component
failure; realignment should not be done until after the
faulty component has been replaced.
We recommend that servicing be performed only by
authorized Yaesu service technicians who are
experienced with the circuitry and fully equipped for
repair and alignment. Therefore, if a fault is suspected,
contact the dealer from whom the transceiver was
purchased for instructions regarding repair.
Authorized Yaesu service technicians realign all circuits
and make complete performance checks to ensure
compliance with factory specifications after replacing any
faulty components. Those who do undertake any of the
following alignments are cautioned to proceed at their
own risk. Problems caused by unauthorized attempts at
realignment are not covered by the warranty policy. Also,
Yaesu must reserve the right to change circuits and
alignment procedures in the interest of improved
performance, without notifying owners. Under no
circumstances should any alignment be attempted unless
the normal function and operation of the transceiver are
clearly understood, the cause of the malfunction has
been clearly pinpointed and any faulty components
replaced, and the need for realignment determined to be
absolutely necessary. The following test equipment
(and thorough familiarity with its correct use) is necessary
for complete realignment. Correction of problems caused
by misalignment resulting from use of improper test
equipment is not covered under the warranty policy.
While most steps do not require all of the equipment
listed, the interactions of some adjustments may require
that more complex adjustments be performed afterwards.
Do not attempt to perform only a single step unless it is
clearly isolated electrically from all other steps. Have all
test equipment ready before beginning, and follow all of
the steps in a section in the order presented.
Required Test Equipment
RF signal generator: calibrated output level at 1000 MHz
(0 dBµ =1.0 µV - closed circuit)
Deviation Meter (linear detector)
AF Millivoltmeter
SINAD Meter
Inline Wattmeter with 5% accuracy at 1000 MHz
Regulated DC Power Supply: adjustable from 10 to 17
VDC, 15A
50-ohm Non-reactive Dummy Load: 100W at 1000 MHz
Frequency Counter: >0.1 ppm accuracy at 1000 MHz
AF Signal Generator
DC Voltmeter: high impedance
RF Sampling Coupler(attenuation pad)
AF Dummy Load: 4 ohm, 20W
Oscilloscope
Spectrum Analyzer
IBM PC/compatible computer w/Yaesu CT-71
programming cable and CE-35 channel programming
editor.
50-ohms RF Signal
Dummy load Generator
RFSampling
Inline Wattmeter Coupler
Transceiver
DeviationMeter CT-70
CT-29 Connection
Frequency Cable Power Supply
Counter IBM PC 13.8V DC
COMport
Alignment Preparation & Precautions
A dummy load and inline wattmeter must be connected to
the main antenna jack in all procedures that call for
transmission, except where specified otherwise. Correct
alignment is not possible with an antenna. After
completing one step, read the following step to determine
whether the same test equipment will be required. If not,
remove the test equipment (except dummy load and
wattmeter, if connected) before proceeding.
Correct alignment requires that the ambient temperature
be the same as that of the transceiver and test
equipment, and that this temperature be held constant
between 20 and 30°C (68 86F). When the transceiver is
brought into the shop from hot or cold air it should be
allowed some time for thermal equalization with the
environment before alignment. If possible, alignments
should be made with oscillator shields and circuit boards
firmly affixed in place. Also, the test equipment must be
thoroughly warmed up before beginning.
Before beginning, connect the transceiver and PC using
the CT-71 programming cable as described in the
EEPROM Programming chapter, and download the
EEPROM data from the transceiver to the computer.
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 procedure are
based on 0 dBm = 0.5 mV (closed circuit).
Caution: Do not connect this 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 circuit used in the
radio, it is necessary to construct and use a simple audio
load test adapter as shown in the schematic diagram
above, when conducting receiver alignment steps.
3.5mmPLUG Attenuated
TestOutput(1/2)
2ohms 10W
Ground
+ 470uF
2ohms 10W
AF Test Adapter Schematic
Alignment Channel Frequencies
VHF TYPE A
Channel Frequency
(simplex) CTCSS Encode DCS Encode Narrow /wide
CH1 134.01MHz None None Wide
CH2 147.01MHz None None Wide
CH3 159.99MHz None None Wide
CH4 134.01MHz None None Narrow
CH5 147.01MHz None None Narrow
CH6 159.99MHz None None Narrow
CH7 147.01MHz 151.4Hz None Wide
CH8 147.01MHz None 023 Wide
CH9 147.01MHz 151.4Hz None Narrow
CH10 147.01MHz None 023 Narrow
VHF TYPE C
Channel Frequency
(simplex) CTCSS Encode DCS Encode Narrow /wide
CH1 148.01MHz None None Wide
CH2 161.01MHz None None Wide
CH3 173.99MHz None None Wide
CH4 148.01MHz None None Narrow
CH5 161.01MHz None None Narrow
CH6 173.99MHz None None Narrow
CH7 161.01MHz 151.4Hz None Wide
CH8 161.01MHz None 023 Wide
CH9 161.01MHz 151.4Hz None Narrow
CH10 161.01MHz None 023 Narrow
UHF TYPE A
Channel Frequency
(simplex) CTCSS Encode DCS Encode Narrow /wide
CH1 400.01MHz None None Wide
CH2 415.01MHz None None Wide
CH3 429.99MHz None None Wide
CH4 400.01MHz None None Narrow
CH5 415.01MHz None None Narrow
CH6 429.99MHz None None Narrow
CH7 415.01MHz 151.4Hz None Wide
CH8 415.01MHz None 023 Wide
CH9 415.01MHz 151.4Hz None Narrow
CH10 415.01MHz None 023 Narrow
UHF TYPE D
Channel Frequency
(simplex) CTCSS Encode DCS Encode Narrow /wide
CH1 450.01MHz None None Wide
CH2 465.01MHz None None Wide
CH3 479.99MHz None None Wide
CH4 450.01MHz None None Narrow
CH5 465.01MHz None None Narrow
CH6 479.99MHz None None Narrow
CH7 465.01MHz 151.4Hz None Wide
CH8 465.01MHz None 023 Wide
CH9 465.01MHz 151.4Hz None Narrow
CH10 465.01MHz None 023 Narrow
UHF TYPE F
Channel Frequency
(simplex) CTCSS Encode DCS Encode Narrow /wide
CH1 480.01MHz None None Wide
CH2 496.01MHz None None Wide
CH3 511.99MHz None None Wide
CH4 480.01MHz None None Narrow
CH5 496.01MHz None None Narrow
CH6 511.99MHz None None Narrow
CH7 496.01MHz 151.4Hz None Wide
CH8 496.01MHz None 023 Wide
CH9 496.01MHz 151.4Hz None Narrow
CH10 496.01MHz None 023 Narrow
PLL & Transmitter
Set up the test equipment as shown for transmitter
alignment.
Maintain the supply voltage at 13.8V DC for all steps.
PLL VCV
Connect the positive lead of the DC voltmeter to the test
point TP1013 (VCV) on the Main Unit, as indicated in the
figure, and the negative lead to chassis ground.
Set the transceiver to the high band edge frequency
channel, then adjust coil on the Unit for 4.2 V on the
voltmeter.
VHF: L1016 / UHF: L1021
Key the transmitter, and adjust coil on the Unit for 4.2 V
on the voltmeter.
VHF: L1017 / UHF: L1022
Next select to the low edge frequency channel and
confirm about 1.0 V (0.8V – 1.2V) on the voltmeter.
Key the transmitter, and confirm about 1.0 V(0.8V – 1.2V)
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, key the transmitter and adjust
TC1001 on the Main Unit, if necessary, so the counter
frequency is within 100 Hz of the channel center
frequency for the transceiver version.

Transmitter Output Power (VHF)
Select band center frequency channel, and select high
power output level.
Key the transmitter and adjust by control commands for
high power from the computer for 50 ± 1 Watts as
indicated on the wattmeter.
Select band center frequency channel, and select low
power output level.
Key the transmitter and adjust by control commands for
low power from the computer for 5 ± 0.1 Watts as
indicated on the wattmeter.
Transmitter Output Power (UHF)
Select band center frequency channel, and select high
power output level.
Key the transmitter and adjust by control commands for
high power from the computer for 40 ± 1 Watts as
indicated on the wattmeter.
Select band center frequency channel, and select low
power output level.
Key the transmitter and adjust by control commands for
low power from the computer for 5 ± 0.1 Watts as
indicated on the wattmeter.
Transmitter Deviation
Microphone Audio Modulation Level
Select band center frequency channel, and adjust the AF
generator for 25mV(-30dBm) output at 1 kHz to the
microphone jack.
Key the transmitter and adjust by control commands for
maximum deviation from the computer for 4.2kHz ±
0.05kHz deviation as indicated on the deviation meter.
CTCSS Modulation Level
Select band center frequency channel, with 151.4 Hz
CTCSS encode, and reduce the AF generator injection to
zero.
Key the transmitter and adjust by control commands for
CTCSS deviation from the computer for 0.7kHz ±
0.05kHz deviation as indicated on the deviation meter.
DCS Modulation Level
Select band center frequency channel, with DCS 023
enabled, reduce the AF generator injection to zero.
Key the transmitter and adjust by control commands for
DCS deviation from the computer for 0.7 kHz ± 0.05 kHz
deviation as indicated on the deviation meter.
Receiver
Set up the test equipment as shown for receiver
alignment, and construct the audio test adapter as
described in the box below.
With the transceiver set to band center frequency
channel, and the RF signal generator tuned to the same
frequency, set the generator for ±3.0kHz deviation (for
25kHz steps) with 1kHz tone modulation, and set the
output level for 1µV at the antenna jack.
Adjust by control commands for tune from the computer
for optimum SINAD, reducing signal generator output
level as necessary for proper meter deflection.
After the previous step, final signal generator level should
be less than 0.25µV for 12dB SINAD.
Squelch Threshold
Select band center frequency channel, and the RF signal
generator turned to the same frequency, set the
generator for ±3.0 kHz deviation with 1kHz tone
modulation, and set the output level for -8dBµ at the
antenna jack.
Adjust the squelch threshold level by control commands
for squelch threshold from the computer so that it just
closes (BUSY LED turns off).