AMERITRON ALS-500M, Инструкция по эксплуатации

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ALS-500M Instruction Manual
3
Supply Voltage
Low voltage solid state amplifiers are very sensitive to power supply voltage changes. For maximum
performance, the voltage should be maintained as high as possible consistent with component life. The
devices used in this amplifier have demonstrated excellent life with supply voltages up to 16 volts, and
will produce the rated output power at 14 volts dc. The output power will decrease by approximately
85 watts per volt as the supply voltage is lowered from 14 to 12 volts.
SWR Considerations
SWR (Standing Wave Ratio) causes higher voltages and/or currents to appear at the output connector
of the amplifier. This problem occurs with all amplifiers regardless of whether tubes or
semiconductors are used in the output stage.
The devices used in the ALS-500M have very good overload tolerance. The low pass output network
in the ALS-500M not extremely sensitive to load impedance changes. This makes the ALS-500M less
sensitive to frequency and SWR changes than many other similar amplifiers. The multiple section
output network and push-pull output configuration used in the ALS-500M also offers excellent
harmonic suppression.
The only danger presented by a high SWR is that the current and power dissipation in the output
devices may exceed safe limits. This can result in heat damage and failure of the amplifying devices.
If the SWR exceeds 2:1 the power level should be reduced until the reflected power is 60 watts or less.
At approximately 70 watts of reflected power the internal safety circuitry will disable the amplifier.
Periodic Maintenance
The lack of high voltage in this unit eliminates the chance of dirt and dust causing high voltage arcing
in this unit. The only deleterious effect of dust and dirt is a reduction in cooling efficiency. The
primary maintenance requirement is to monitor the amount of dirt and dust in the amplifier, and
remove the dust and dirt before cooling problems begin. Low pressure compressed air can be used to
blow the dust out of this amplifier whenever a noticeable accumulation of dust builds up.
A soft bristled brush and a small amount of alcohol can be used to clean stubborn dust from the fan or
the other components. Be careful not to get any cleaning compounds on relay contacts or in switches.
If it becomes necessary to perform maintenance on any switch or relay contact Ameritron. Ameritron
has free technical support for customers that wish to service their own equipment.
Technical Assistance
Ameritron has free technical information bulletins that provide assistance with the most common
operational problems. Technical assistance is also available by calling (662) 323-8211 or FAX (662)
323-6551 during our normal business hours (8:00 to 4:30 Central Time on weekdays) for questions that
are not properly addressed by the technical bulletins. Ameritron's policy is to provide complete
technical support to our customers. Before calling, please have the following information available:
1. The model and serial number the unit.
2. The date of purchase and the dealer.
3. A brief description of the station equipment and antenna system.
4. A complete description of the problem along with all meter readings.