AMERITRON ALS-600 - AM Operation; Drive Power Requirements

The power supply high voltage output can be reduced to increase the efficiency at lower
output levels. At 30 volts the ALS-600 will deliver 275 watts of output power. This
allows a 100% duty cycle with any fan delivering more than 40 CFM at .08" of static
pressure, or a 5 minute on, two minute off duty cycle with the standard fan. Consult the
factory if you wish to reduce the high voltage output.level.
Either the exciter drive level or the amplifier "ALC SET" control can be adjusted to limit
the power output in the RTTY and FM modes.
AM Operation
AM operation requires that the carrier power of any linear amplifier be restricted to one
fourth of the peak envelope output power. With this amplifier, the maximum carrier
power on AM should be set for no more than 150 watts.
Proper modulation AM is indicated by observing the ratio of unmodulated carrier power
to the power indicated on voice modulation peaks. This should be approximately 4:1.
Never use the ALC to control the power on AM. The "ALC SET" control should be set
to the maximum clockwise position.
Drive Power Requirements
The ALS-600 requires less than 100 watts of drive to produce full output power.
Exceeding 100 watts of drive for short periods of time will cause distortion and increase
the bandwidth of the transmitted signal. Exceeding 100 watts of drive for long periods of
time may cause component failures.
Follow these instructions in numerical order. Consult the exciter manual if necessary.
Be sure the power supply transformer is correctly wired for your line voltage. See the
"Line Voltage Modifications" section for wiring details.
1. Set the ALS-600 front panel switches as follows:
ON-OFF to OFF
OPERATE-STANDBY to STANDBY
2. Plug the AC line cord into the proper voltage outlet.
3. Place the power switch in the ON position. The meter lamps should light and the
power supply and amplifier fans should start.
4. Check the voltage on the power supply meter. The ALS-600PS voltage should be
between 55 and 65 volts at this step. If the voltage is outside this range then check
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