Vertex Standard VX-2000U, Service Manual, Page: 19 / 65

19
Alignment
The VX-2000 is carefully aligned at the facto-
ry for the specified performance across the de-
signed frequency range. Realignment should,
therefore, not be necessary except in the event of
a component failure, or when altering the fre-
quency range (“version”).
The following procedures cover the sometimes-
critical and tedious adjustments that are not nor-
mally required once the transceiver has left the
factory. However, if damage has occurred and
some parts subsequently are replaced, alignment
may be required in order to restore the original
alignment. If a sudden problem occurs during oth-
erwise normal operation, it is likely due to part
failure, and realignment should be performed only
after the faulty component has been replaced.
All component replacement and service
should be performed only by an authorized
Vertex representative, or the warranty policy
may be voided. Vertex service technicians are ex-
perienced with the circuitry, and are fully
equipped for part replacement and alignment.
When any repairs are completed, Vertex service
technicians perform comprehensive performance
checks to ensure that total transceiver system per-
formance complies with each and every specifi-
cation for this product.
Those who undertake any of the following
alignment procedures are cautioned to proceed
at their own risk. Problems caused by unautho-
rized attempts at realignment are not covered by
the warranty policy covering this transceiver.
Also, Vertex reserves the right to change circuits
and alignment procedures, in the interest of im-
proved performance, without notifying owners.
Under no circumstances should any alignment
be attempted unless the normal function and op-
eration of the radio are fully understood, the cause
of the malfunction has been clearly pinpointed and
any/all faulty components replaced, and realign-
ment determined to be absolutely necessary.
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 the use
of improper test equipment is not covered by our
warranty policy.
While most steps do not require all the test
equipment listed, the interactions of some adjust-
ments may require that more complex adjust-
ments be performed afterwards. Do not, there-
fore, attempt to perform only a single step un-
less it is clearly isolated electrically from all oth-
er steps. Have all test equipment ready before
beginning, and follow all of the steps in a section
in the order presented.
r
RF Signal Generator with calibrated output to
550 MHz
r
Deviation Meter (linear detector)
r
In-line Wattmeter with 5% accuracy at 550 MHz
r
50-
W
Dummy Load with a power rating of 50
W at 550 MHz
r
Regulated DC Power Supply, adjustable from
10 V to 17 V DC at 10 A
r
Frequency Counter with 0.2 ppm accuracy at
550 MHz
r
AF Signal Generator
r
DC Voltmeter, high impedance
r
SINAD Meter
r
IBM PC
®
/compatible computer with Microsoft
Windows
®
v3.1 (or later) installed
r
Vertex VPL-1 Connection Cable and CE-20
Channel Programming Diskette
r
UHF Sampling Coupler