Alignment - Vertex Standard VX-1210 Service Manual

The VX-1210 is carefully aligned at the factory for the speci-
fied performance across the entire operating frequency range.
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 Vertex Standard rep-
resentative, or the warranty policy may be void.
The following procedures cover the sometimes critical and
tedious adjustments that are not normally required once the trans-
ceiver has left the factory. However, if damage occurs and some
parts subsequently are placed, 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 autho-
rized Vertex Standard 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 repeater was purchased for instructions regarding repair. Au-
thorized Vertex Standard 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 un-
authorized attempts at realignment are not covered by the war-
ranty policy. Also, Vertex Standard reserves 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 realignment
determined to be absolutely necessary.
The following test equipment (and thorough familiarity with
its correct use) is necessary for complete realignment. Correc-
tion 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 com-
plex 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
r RF Signal Generator with calibrated output level at 30 MHz
r Spectrum Analyzer
r In-line Wattmeter with 5 % accuracy at 30 MHz
r 50 W RF Dummy Load with power rating 50W at 30MHz
r Frequency Counter with 0.02 ppm accuracy at 40 MHz
r AF Signal Generator
r AC Voltmeter
r DC Voltmeter: High input impedance
r DC Ammeter
r HF Sampling Coupler
r IBM PC / compatible Computer with MS-DOS or later oper-
ating system
r Vertex Standard SVC-1200 Service Set & CE42 Channel/
Alignment Diskette
Alignment Preparation & Precautions
A 50 W RF Dummy Load and in-line wattmeter must be con-
nected to the ANT jack in all procedures that call for transmis-
sion, except where specified otherwise. Correct alignment is not
possible with an antenna.
After completing one step, read the following step to deter-
mine whether the same test equipment will be required. If not,
remove the test equipment (except dummy load and wattmeter,
in 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 68 °F and 86 °F (20
°C ~ 30 °C). When the transceiver is brought into the shop from
hot or cold air, it should be allowed time to come to room tem-
perature before alignment.
Whenever possible, alignments should be made with oscilla-
tor shields and circuit boards firmly affixed in place. Also, the
test equipment must be thoroughly warmed up before beginning.
Note: Signal levels in dB referred to in the alignment procedure
are based on 0dBµ = 0.5µV (Closed Circuit).

Alignment

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