Vertex Standard VX-6000U, Руководство по обслуживанию

Страница: 14 / 44

9-1
VX-6000 UHF Service Manual
Alignment
The VX-6000 has been carefully aligned at the fac-
tory for the specified performance across the frequen-
cy range specified for each version.
Realignment should therefore not be necessary
except in the event of a component failure, or when
altering the transceiver version. If a sudden prob-
lem occurs during normal operation, it is likely due
to component failure; realignment should not be
done until after the faulty component has been re-
placed. All component replacement and service
should be performed only by an authorized
VER-
TEX STANDARD
representative, or the warranty
policy may be voided. Therefore, if a fault is suspect-
ed, contact the dealer from whom the transceiver was
purchased for instructions regarding repair.
Authorized VERTEX STANDARD service tech-
nicians realign all circuits and make complete per-
formance checks to ensure compliance with factory
specifications after replacing any faulty components.
Those who do undertake any of the following align-
ments are cautioned to proceed at their own risk.
Problems caused by unauthorized attempts at re-
alignment are not covered by the warranty policy.
Also,
VERTEX STANDARD
must reserve the right
to change circuits and alignment procedures in the
interest of improved performance, without notify-
ing 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.
Required Test Equipment
The following test equipment (and thorough fa-
miliarity with its correct use) is necessary for com-
plete realignment. Correction of problems caused by
misalignment resulting from use of improper test
equipment is not covered under the warranty poli-
cy.
While most steps do not require all of the equip-
ment listed, the interactions of some adjustments
may require that more complex adjustments be per-
formed 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 sec-
tion in the order presented.

RF signal generator: calibrated output level at 1000
MHz

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, 35A

50-ohm non-reactive Dummy Load: 200 W 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 ohms, 20W

Oscilloscope

Spectrum Analyzer

IBM PC-compatible computer w/VERTEX
STADARD CT-88 programming cable and SVC49
channel programming editor
Alignment Preparation & Precautions
A dummy load and inline wattmeter must be con-
nected to the main antenna jack in all procedures
that call for transmission, except where specified oth-
erwise. Correct alignment is not possible with an
antenna. After completing one step, read the follow-
ing step to determine whether the same test equip-
ment will be required. If not, remove the test equip-
ment (except dummy load and wattmeter, if connect-
ed) before proceeding.
Correct alignment requires that the ambient tem-
perature be the same as that of the transceiver and
test equipment, and that this temperature be held
constant between 68° and 86°F (20° ~ 30°C). 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 oscilla-
tor shields and circuit boards firmly affixed in place.
Also, the test equipment must be thoroughly warmed
up before beginning.