Alignment, Introduction, Required test equipment – Vertex Standard VX-4200 User Manual
Page 11: Alignment preparation & precautions
Introduction
The VX-4100/-4200 series has been aligned at the factory
for the specified performance across the entire frequency
range specified. Realignment should therefore not be nec-
essary except in the event of a component failure. All com-
ponent replacement and service should be performed only
by an authorized Vertex Standard representative, or the
warranty policy may be voided.
The following procedures cover the sometimes critical and
tedious adjustments that are not normally required once
the transceiver has left the factory. However, if damage
occurs and some parts are replaced, realignment may be
required. If a sudden problem occurs during normal op-
eration, 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 au-
thorized Vertex Standard service technicians who are ex-
perienced with the circuitry and fully equipped for repair
and alignment. Therefore, if a fault is suspected, contact
the dealer from whom the transceiver was purchased for
instructions regarding repair. Authorized 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 unauthorized attempts at realignment 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, with-
out 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 the need for realign-
ment determined to be absolutely necessary. The follow-
ing test equipment (and thorough familiarity with its cor-
rect 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 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 fol-
low all of the steps in a section in the order presented.
Required Test Equipment
Radio Tester with calibrated output level at 200 MHz
In-line Wattmeter with 5% accuracy at 200 MHz
50-ohm, 50-W RF Dummy Load
Regulated DC Power Supply (standard 13.6V DC, 15A)
Frequency Counter: ±0.2 ppm accuracy at 200 MHz
AF Signal Generator
AC Voltmeter
DC Voltmeter
VHF Sampling Coupler
Microsoft® Windows® 95 or later operating system
Vertex Standard VPL-1 Connection Cable and CE59
Alignment program
Alignment Preparation & Precautions
A 50-ohm RF Dummy load and in-line wattmeter must be
connected to the main antenna jack in all procedures that
call for transmission, except where specified otherwise.
Correct alignment is not possible with an antenna.
Beacuse of the BTL (Bridged TransLess) Amplifier circuit
used in the VX-4200/-4100, do not connect eather side of
the speaker leads to chassis "ground."
After completing one step, read the following step to de-
termine whether the same test equipment will be 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 °C
and 30 °C (68 °F ~ 86 °F). When the transceiver is brought
into the shop from hot or cold air, it should be allowed
time to come to room temperature before alignment.
Whenever possible, alignments should be made with os-
cillator 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 this procedure are
based on 0 dBµ EMF = 1.0 µV.
Alignment
F-1