Introduction
The
be necessary except in the event of a component failure, or altering version type. All component replacement and service should be performed only by an authorized Vertex Standard representative,or the warranty policy may be void.
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 subsequently are placed, realign-
ment may be required. If a sudden problem occurs during normal operation, it is likely due to component fail- ure; 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. 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
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. Correction of problems caused by misalignment result-
ing 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 follow all of
the steps in a section in the order presented.
Alignment
Required Test Equipment
rRF Signal Generator with calibrated output level at 500MHz
rDeviation Meter (linear detector)
r
r50W RF Dummy Load with power rating 100W at 500MHz
r4W AF Dummy Load
rRegulated DC Power Supply (standard 13.6V DC, 15A)
rFrequency Counter with 0.1ppm accuracy at 500MHz
rAC Voltmeter
rDC Voltmeter
rVHF Sampling Coupler
rIBM PC/compatible Computer
rOscilloscope
rVertex Standard
Alignment Preparation & Precautions
A50W RF Dummy Load and
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.
After completing one step, read the following step to determine 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 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 the alignment procedure are based on 0dBµV = 0.5µV into 50W.
11