Verizon VXA-220 User manual

Air Band Transceiver
VXA-220
Service Manual
Introduction
This manual provides technical information necessary for servicing the VXA-
220 Air Band Transceiver.
Servicing this equipment requires expertise in handling surface-mount chip
components. Attempts by non-qualified persons to service this equipment may
result in permanent damage not covered by the warranty, and may be illegal
in some countries.
Two PCB layout diagrams are provided for each double-sided circuit board in
the transceiver. Each side of thr board is referred to by the type of the majority
of components installed on that side (“leaded” or “chip-only”). In most cases
one side has only chip components, and the other has either a mixture of both
chip and leaded components (trimmers, coils, electrolytic capacitors, ICs, etc.),
or leaded components only.
While we believe the technical information in this manual to be correct, Vertex
Standard assumes no liability for damage that may occur as a result of typo-
graphical or other errors that may be present. Your cooperation in pointing
out any inconsistencies in the technical information would be appreciated.
©2006 VERTEX STANDARD CO., LTD. (EC072N90A)
Contents
Specifications............................................................................................................................................................... 2
Exploded View & Miscellaneous Parts .................................................................................................................. 3
Block Diagram ............................................................................................................................................................. 5
Circuit Description ..................................................................................................................................................... 7
Alignment ..................................................................................................................................................................... 9
MAIN Unit Circuit Diagram .................................................................................................................................. 13
MAIN Unit Parts Layout ......................................................................................................................................... 15
MAIN Unit Parts List ............................................................................................................................................... 17
Important Note
This transceiver was assembled using Pb (lead) free solder, based on the RoHS specification.
Only lead-free solder (Alloy Composition: Sn-3.0Ag-0.5Cu) should be used for repairs performed on this
apparatus. The solder stated above utilizes the alloy composition required for compliance with the lead-free
specification, and any solder with the above alloy composition may be used.
VERTEX STANDARD CO., LTD.
4-8-8 Nakameguro, Meguro-Ku, Tokyo 153-8644, Japan
VERTEX STANDARD
US Headquarters
10900 Walker Street, Cypress, CA 90630, U.S.A.
YAESU EUROPE B.V.
P.O. Box 75525, 1118 ZN Schiphol, The Netherlands
YAESU UK LTD.
Unit 12, Sun Valley Business Park, Winnall Close
Winchester, Hampshire, SO23 0LB, U.K.
VERTEX STANDARD HK LTD.
Unit 5, 20/F., Seaview Centre, 139-141 Hoi Bun Road,
Kwun Tong, Kowloon, Hong Kong
VERTEX STANDARD (AUSTRALIA)PTY., LTD.
Normanby Business Park, Unit 14/45 Normanby Road
Notting Hill 3168, Victoria, Australia

2
General
Frequency Range: TX: 118.000 - 136.975 MHz,
RX: 108.000 - 136.975 MHz,
Weather Channels (WX-01 - WX-10: USA version only)
Channel Spacing: 25 kHz
Emission Type: TX: AM,
RX: AM & FM (FM: for receiving the Weather Channels, USA version only)
Supply Voltage: 6.0 - 15.0 VDC
Current Consumption (approx.): 250 μA (power off),
35 mA (battery saver on, saver ratio 1:5)
60 mA (squelch on),
200 mA (receive),
850 mA (transmit 1.5 W Carrier)
Temperature Range: +14 °F to + 140 °F (–10 °C to +60 °C)
Case Size (WxHxD): 2.36 x 4.09 x 1.2 inches (60 x 104 x 30.5 mm) w/o knob & antenna
Weight (approx.): 12.7 oz (360 grams) with FNB-83, antenna, and belt clip
Receiver
Circuit Type: Double-conversion superheterodyne
IFs: 47.25 MHz & 450 kHz
Sensitivity: AM: Better than 0.8 μV (for 6 dB S/N with 1 kHz, 30 % modulation)
FM; Better than 0.4 μV (for 12 dB SINAD)
Selectivity: More than 8 kHz/–6 dB
Adjacent CH. Selectivity: Less than 25 kHz/–60 dB
AF Output (Internal speaker): 0.7 W @ 16 Ohms, 10 % THD
Transmitter
Power Output (@ 7.2 V): 5 W (PEP), 1.5 W (Carrier Power)
Frequency Stability: Better than ±10 ppm (+14 °F to + 140 °F [–10 °C to +60 °C])
Modulation System: Low Level Amplitude Modulation
Spurious Emission: >60 dB below carrier
Int. Microphone Type: Condenser
Ext. Mic. Impedance: 150 Ohms
Specifications are subject to change without notice or obligation.
Specifications
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9
Alignment
Introduction
The VXA-220 is carefully aligned at the factory for the
specified performance across the Aircraft and Weather
bands. Realignment should therefore not be necessary
except in the event of a component failure.
The following procedures cover the adjustments that are
not normally required once the transceiver has left the
factory. However, if damage occurs and some parts sub-
sequently are replaced, realignment may be required. If a
sudden problem occurs during normal operation, it is like-
ly 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 au-
thorized Vertex Standard service technicians who are ex-
perienced with the circuitry and fully equipped for re-
pair and alignment. If a fault is suspected, contact the
dealer from whom the transceiver was purchased for in-
structions regarding repair. Under no circumstances
should any alignment be attempted unless the normal
function and operation of the transceiver are clearly un-
derstood, the cause of the malfunction has been clearly
pinpointed and any faulty components replaced, and re-
alignment determined to be absolutely necessary. Prob-
lems caused by unauthorized attempts at realignment are
not covered by the warranty policy
Vertex Standard reserves the right to change circuits and
alignment procedures, in the interest of improved perfor-
mance, without notifying owners.
The following test equipment (and familiarity with its use)
is necessary for complete realignment. While most steps
do not require all of the equipment listed, the interactions
of some adjustments may require that more complex ad-
justments be performed afterwards. Do not attempt to
perform only a signal step unless it is clearly isolated elec-
trically from all other steps. Have all test equipment ready
before beginning, and follow all of the steps in a section
in the order presented.
Correction of problems caused by misalignment result-
ing from use of improper test equipment is not covered
under the warranty policy.
Required Test Equipment
Radio Tester with calibrated output level at 200 MHz
In-line Wattmeter with 5 % accuracy at 200 MHz
50 Ohm, 10 W RF Dummy Load
Regulated DC Power Supply adjustable from 3 to 15
VDC, 2 A
Frequency Counter: ±0.2 ppm accuracy at 200 MHz
AF Signal Generator
AC Voltmeter
DC Voltmeter: high impedance
VHF Sampling Coupler
Alignment Preparation & Precautions
A 50 Ohm RF load and in-line wattmeter must be con-
nected to the main antenna jack in all procedures that call
for transmission, except where specified otherwise. Cor-
rect alignment is not possible with an antenna. After com-
pleting one step, read the next step to see if the same test
equipment is 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 -
30 °C (68 - 86 °F). When the transceiver is brought into the
shop from hot or cold air, it should be allowed some time
to come to room temperature before alignment. Whenev-
er possible, alignments should be made with oscillator
shields and circuit boards firmly affixed in place. Also,
the test equipment must be thoroughly warmed up be-
fore beginning.
Set up the test equipment as shown below for transceiver
alignment, apply 7.2 VDC power to the transceiver.
Notes: signal levels in dB referred to in alignment are
based on 0 dBμ= 0.5 μV (closed circuit).
F
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