Yaesu FT-1900R, Technical Supplement

Page: 9 / 34

9
Alignment
Introduction
The FT-1900R is carefully aligned at the factory for
the specified performance across the amateur band.
Realignment should therefore not be necessary ex-
cept in the event of a component failure. Only an
authorized Vertex Standard representative should
perform all component replacement and service, or
the warranty policy may be void.
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 subsequently are replaced, realignment may
be required. If a sudden problem occurs during nor-
mal 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 Vertex Standard service technicians
who are experienced with the circuitry and fully
equipped for repair and alignment. If a fault is sus-
pected, contact the dealer from whom the transceiver
was purchased for instructions regarding repair.
Authorized Vertex Standard service technicians re-
align all circuits and make complete performance
checks to ensure compliance with factory specifica-
tions 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 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.
Required Test Equipment
The following test equipment (and familiarity with
its use) is necessary for complete realignment. Cor-
rection of problems caused by misalignment result-
ing from use of improper test equipment is not cov-
ered under the warranty policy. While most steps
do not require all of the equipment listed, the inter-
actions 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 pre-
sented.
ˆ
RF Signal Generator with calibrated output level
at 200 MHz
ˆ
Deviation Meter (linear detector)
ˆ
In-line Wattmeter with 5% accuracy at 200 MHz
ˆ
50-Ohm 50-W RF Dummy Load
ˆ
8-Ohm AF Dummy Load
ˆ
Regulated DC Power Supply adjustable from 6
to 15 VDC, 10A
ˆ
Frequency Counter: 0.2-ppm accuracy at 200 MHz
ˆ
AF Signal Generator
ˆ
AC Voltmeter
ˆ
DC Voltmeter: high impedance
ˆ
VHF Sampling Coupler
ˆ
SINAD Meter