AMERITRON ALS-706 - User Manual

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Summary

Installation and Operation

Placement Guidelines

Guidelines for positioning the amplifier and power supply for optimal operation and ventilation.

Power Line or Mains Connections

Details on connecting the amplifier system to the electrical power mains, including voltage and plug types.

Radio and Antenna Connections

Instructions for connecting RF cables and ALC/keying lines between the amplifier and transceiver.

General Operation and System Details

Power Supply and Power Requirements

Detailed features and requirements for the ALS-600PS and ALS-600SPS power supplies.

Power Line Requirements

Specifications for connecting the amplifier to AC power mains, including voltage and fuse details.

Power Supply Location Recommendations

Recommendations for placing the power supply unit to ensure proper ventilation and minimize interference.

Amplifier Overview

General description of the ALS-706 amplifier, its design, and key components.

System Installation

Installation Clearances

Required space around the amplifier and power supply for adequate airflow and heat dissipation.

Installation Warnings

Crucial safety warnings and precautions related to installing accessory equipment and devices.

Installation, Wiring, and Connections

Step-by-step guide for wiring the power supply, connecting components, and ensuring proper fuse installation.

Safety and Lightning Grounding

Essential guidelines for grounding the system and protecting against lightning strikes for safety.

Station RF Grounding

Information and best practices for establishing an effective RF ground system for station equipment.

Coaxial Line Isolators

Guidance on the use and placement of coaxial line isolators to manage common mode currents.

Front Panel Controls and Indicators

Interconnections and Cabling

RF IN Connection

Connection details for the RF input signal from the transceiver to the amplifier.

RF OUT Connection

Connection details for the amplified RF output signal to the antenna or other station equipment.

RADIO INTERFACE Port

Information on using radio interface cables for automatic band selection and amplifier actuation.

REMOTE Control Connection

Details on connecting Ameritron remote control heads or interface boxes for remote operation.

KEY LOOP Functionality

Explanation of the Key Loop jack and switch for use with automatic antenna tuners.

Optional Radio Interface Cables

Initial Operation and Testing

ALC Adjustment Procedure

Procedure for adjusting the Automatic Level Control (ALC) for optimal power output and stability.

High Duty Cycle Modes Operation

Recommendations for operating the amplifier in modes like FT8, RTTY, or FM to prevent overheating.

ALS-600 SPS Switching Power Supply Configuration

The Ameritron ALS-706/S is a solid-state, 600-watt nominal PEP output amplifier designed for amateur radio use, covering 160 through 6 meters. It utilizes an external power supply system and is optimized for 50-ohm loads. The amplifier is compact, measuring 9.5" wide by 7" high by 14" deep, and weighs approximately 15 pounds.

Function Description:

The ALS-706/S amplifies radio frequency (RF) signals from a transceiver, increasing their power output for transmission. It supports operation across the 160, 80/75, 40, 30, 20, 17, 15, 12, 10, and 6-meter amateur radio bands. A key feature is its "no tune" operation, simplifying setup and use. The amplifier includes automatic band selection when connected to compatible transceivers via an Ameritron interface cable, supporting ICOM, Elecraft, Yaesu, and Kenwood band data inputs.

Important Technical Specifications:

Output Power: 600 watts nominal PEP.
Frequency Coverage: 1.8 MHz to 54 MHz (160-6 meters).
Drive Power: 100 watts or less (nominal 80-100 watts for 600 watts output, approximately 9-10 dB gain).
Transistor: One conservative linear-service rated 50-volt Dual LDMOS FET (MRFE6VP5600HR6).
Power Supply: External 50-volt 25-ampere CCS power supply (ALS-600SPS switching regulated supply or ALS-600PS unregulated choke input supply). The power supply also provides 14-volt positive and negative supplies for illumination, bias, and control.
Power Line Requirements:
- ALS-600SPS: 95-130 VAC 50-400 Hz 15A (automatically adapts).
- ALS-600PS: 100-130 VAC 50-60 Hz 15A (requires tap changes for 240V).
- 240V operation is possible with 8A maximum, fast blow 250VAC fuses.
ALC Output: Standard negative-going ALC with front panel adjustment.
Relay Line: Low voltage (<14V), low current (<20 mA) for transceiver keying.
Harmonic Suppression: Excellent, achieved through push-pull operation and 5-pole low-pass filters.
Cooling System: Quiet variable-speed forced-air cooling with temperature sensors.
Dimensions: 14” deep x 7" high x 9.5" wide (amplifier section).
Weight: 15 pounds (amplifier section).
FCC Lockout: Automatic disconnect and other features prevent 27-MHz operation.

Usage Features:

Front Panel Controls:
- MULTIMETER: Displays FET Module Current, Voltage, ALC, and Reflected Power on the right scale (0-70 volts/amperes) and Forward Power Output on the left scale (0-1000 watts).
- BAND SELECT: Rotary knob for manual band selection or REMote operation.
- BAND INDICATOR: Backlit LEDs indicate selected band (160, 80, 40, 30, 20, 17, 15, 12, 10, 6 meters, or REM). Flashes for warnings.
- ALC SET: Knob for ALC limit adjustment.
- ALARM INDICATORS: LEDs for ALC (yellow, indicates output), SWR, PA (fault), and TX (green, transmit mode). SWR and PA indicators flash in codes for severe operational problems.
- MULTIMETER SELECTOR: Switch to select what the multimeter displays (HV, ALC, REF, CUR).
- OPERATE/STANDBY: Switch to enable/disable amplifier operation and reset fault warnings.
- MAIN POWER: Switch to turn the amplifier on/off and reset power supply overload.
Automatic Band Selection: Available with optional Ameritron radio interface cables for ICOM, Elecraft, Yaesu, and Kenwood transceivers.
Protection Circuitry:
- Reflected power protection.
- Thermal overload protection (PA FET too hot).
- Bandswitch error protection (wrong filter, filter input SWR).
- Disables operation for illegal 11-meter signals or bad band data.
- Shuts down for incorrect band selection or high antenna SWR.
High Duty Cycle Modes: For modes like FM, RTTY, FT8, or other digital modes, reduce power input to less than 600W and PA current to less than 20A to prevent thermal cutouts.
ALC Adjustment: A small flat-blade screwdriver adjustment on the left cabinet side allows fine-tuning of ALC gain to prevent "power bounce."

Maintenance Features:

Easy-to-Service Modular Construction: Designed for straightforward maintenance.
Fault-Error Diagnosis: Front panel LED indicators provide rapid diagnosis of operational faults.
Power Supply Fuses: The ALS-600PS uses protective fuses (15A 250V for 120V operation, 8A 250V for 240V operation).
Power Supply Voltage Settings:
- ALS-600PS: Requires opening the supply and changing solder jumpers to set the line voltage range (95-110V, 105-120V, 115-130V, 200-220V, 210-230V, 220-240V).
- ALS-600SPS: Requires opening the supply and moving jumpers to switch between 120V and 240VAC. Capacitors must be discharged before opening.
Grounding: Rear panel ground lug for connection to a station ground bus. Proper safety and lightning grounding practices are emphasized, including bonding to the mains entrance ground rod.
Ventilation: Requires clear airflow to inlets (top left, lower right, right side cabinet bottom) and outlets (rear vents). Avoid blocking ventilation holes and exposure to moisture, water, or external heat.
RF Exposure Information: Detailed charts are provided for controlled and uncontrolled RF exposure distances at various power levels, frequencies, and antenna gains, in compliance with FCC regulations.