Introduction
The
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 authorized Vertex Standard service technicians who are experienced with the circuitry and fully equipped for re- pair and alignment. Therefore, if a fault is suspected, con- tact the dealer from whom the transceiver was purchased for instructions regarding repair. Authorized Vertex Stan- dard service technicians realign all circuits and make com- plete performance checks to ensure compliance with fac- tory 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 re- serve the right to change circuits and alignment proce- dures 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 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 af- terwards. 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.
Alignment
Required Test Equipment
Avionics Radio Tester with calibrated output level at 1 GHz
Regulated DC Power Supply (standard 7.5V DC, 2A)
Frequency Counter: ±0.2 ppm accuracy at 1 GHz
AF Signal Generator
AC Voltmeter
DC Voltmeter
UHF Sampling Coupler
Microsoft® Windows®95 or later operating system
Vertex Standard
Alignment Preparation & Precautions
A
After completing one step, read the following step to determine whether the same test equipment will be re- quired. If not, remove the test equipment (except dummy load and wattmeter, if connected) before proceeding.
Correct alignment requires that the ambient tempera- ture be the same as that of the transceiver and test equip- ment, and that this temperature be held constant between 68°~ 86°F (20° and 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 oscillator 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 = 0.5 µV (closed circuit).
Important Note
When connecting the
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