Vertex Standard VX-127 User manual

FCC ID: K6620224X20
IC IF: 511B-20224X20
Alignment
Vertex Standard Co., Ltd.
1
VX-127/VX-177 Alignment
Introduction and Precautions
The VX-127/VX-177 has been carefully aligned at the factory for the specified performance
across the 430 MHz amateur band. Realignment should therefore not be necessary except
in the event of a component failure. 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.

FCC ID: K6620224X20
IC IF: 511B-20224X20
Alignment
Vertex Standard Co., Ltd.
2
Required Test Equipment
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.
Regulated DC Power Supply: adjustable from 5 to 16 VDC, 3 A
RF Signal Generator with calibrated output level at 500 MHz
Frequency Counter: ±0.1 ppm accuracy at 500 MHz
AF Signal Generator
SINAD Meter
Oscilloscope
Spectrum Analyzer
Deviation Meter (linear detector)
AF Milivoltmetr
AF Dummy Load: 8 Ω, 1 W
DC Voltmeter: high impedance
Inline Wattmeter with 5% accuracy at 500 MHz
50-Ohm non-reactive Dummy Load: 10 watts at 500 MHz
VHF/UHF Sampling Coupler
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 in the repair shop be the same as
that of the transceiver and test equipment, and that this temperature be held constant
between 20 °C and 30 °C (68 °C to 86 °F). 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

FCC ID: K6620224X20
IC IF: 511B-20224X20
Alignment
Vertex Standard Co., Ltd.
3
and circuit boards firmly affixed in place. Also, the test equipment must be thoroughly
warmed up before beginning.
Notes: Signal levels in dB referred to in alignment are based on 0 dBµ = 0.5 µV.
All items tune and/or adjust by Auto-Tuning Mode or Manual Tuning Mode.
PLL Reference Frequency
With the wattmeter, dummy load and frequency counter connected to the antenna jack.
Tune the transceiver 435.05 MHz and set the TX power level to low power mode.
Key the transceiver, adjust the counter frequency is within ±100 Hz of 435.05 MHz.
Transmitter Deviation
With the wattmeter, dummy load and deviation meter connected to the antenna jack.
Inject a 1 kHz audio signal as a level of 80 mV to the microphone-input port.
Key the transmitter on 440.05 MHz. Adjust the frequency deviation is within 4.3-4.7 kHz
on the deviation meter.
CTCSS Deviation
With the wattmeter, dummy load and deviation meter connected to the antenna jack.
Key the transmitter on 440.05 MHz. Adjust the frequency deviation is within 0.65-0.75
kHz on the deviation meter.
DCS Deviation
With the wattmeter, dummy load and deviation meter connected to the antenna jack.
Key the transmitter on 440.05 MHz. Adjust the frequency deviation is within 0.65-0.75
kHz on the deviation meter.

FCC ID: K6620224X20
IC IF: 511B-20224X20
Alignment
Vertex Standard Co., Ltd.
4
Transmitter Power
With the power meter, dummy load and deviation meter connected to the antenna jack.
Key the transmitter on 440.05 MHz. Adjust the output power is within 5 ±0.1 W on the
power meter. (HI)
Key the transmitter on 440.05 MHz. Adjust the output power is within 2 ±0.1 W on the
power meter. (MID)
Key the transmitter on 440.05 MHz. Adjust the output power is within 0.5 ±0.05 W on
the power meter. (LOW)
Receiver Sensitivity
With the dummy load and SINAD meter connected to the external speaker jack.
Inject a RF signal as a level of -9 dBµV to the antenna jack.
Tune the receiver on 440.05 MHz. Adjust the SINAD is above 12 dB on the SINAD
meter.