ACOM 1003 HF + 6 meter Linear Amplifiers

ACOM 1003 HF + 6 meter Linear Amplifiers are self-contained, full-featured units that cover all amateur bands from 1.8 MHz to 54 MHz. With less than 80 watts input, they deliver 1000 watts PEP output or 900 W continuous carrier using a single ceramic/metal power triode 3CX800A7. The ACOM 1003 models have two new front panel relay switches, one to select from three antenna outputs and another to quickly engage and disengage an input attenuator for rapid tuning without transceiver adjustment. A multitude of advanced features in this compact and affordable amplifier validates its admirable design.

ACOM 1003 Amplifiers are available from DX Engineering in three versions:

• AOM-1003-240 Tested with a preinstalled NEMA 6-15P for 240 VAC at 8.5A (10A fuses)

• AOM-1003-120 Tested with a preinstalled NEMA 5-15P for 120 VAC at 15A+ (20A fuses)

• AOM-1003 Install your own power plug, voltage taps preset to 240VAC internally, 10A fuses supplied

The ACOM1003 HF+6M Linear Amplifier is amazingly easy to operate with these features!

True Resistance Indicator (TRI) bar scale meter: Simplifies accurate adjustment of plate-load impedance controls.

Two-line OLED Display: Provides a peak power bar graph meter, 18 unique operational parameters and text status messages.

External Tuner Not Needed: For antenna SWR up to 3:1, even at 1000 W output.

Front-panel Input Attenuator: Instantly reduces input power when tuning, eliminating the need for transceiver power adjustments.

Silent HF Reed Relay: Enables Fast T/R switching for QSK CW.

Additional features and protection:

• Operator selectable class AB₂ mode for best linearity in SSB mode or class B for reduced plate dissipation in continuous digital modes.

• Operator selectable Full 100% or 50% power output with no efficiency deterioration.

• Auto controlled air flow tube cooling.

• Continuous monitoring of amplifier parameters and tube protection.

• Able to monitor 18 operator-selectable amplifier parameters on the display.

• Unique ACOM protection for the bands switch.

• Factory tuned input lowpass filters for best linearity and input SWR less than 1.3 in each amateur radio band.

OLED comment display – Two-line OLED display with peak-reading forward-output power bar graph and 18 operator-selectable amplifier parameters on the display.

Three antenna outputs – Three antenna outputs are selectable by a push-button on the front panel.

Less noise in the shack – HF antenna reed relay for a virtually silent, QSK compatible CW operation.

Transceiver-independent – The amplifier operates without special signals from the transceiver - "Ground on TX" (PTT) and 50-80 W RF drive power are sufficient.

Single tube operation – Uses a single ceramic/metal power triode 3CX800A7 in cathode driven, grounded grid configuration.

Tube protection – Continuous monitoring of amplifier parameters and tube protection.

Output RF arc protection – Original ACOM HF arc protection at the output, or at the antenna.

Power supply – A rugged toroidal transformer operates on single phase mains power, 90-132 / 180-264 VAC at 50-60 Hz, power consumption at rated output – up to 2000 VA @ 240 VAC. Internal taps for 8 nominal AC mains voltages: 100, 110, 120, 200, 210, 220, 230 & 240VAC, ±10% tolerance), 50-60 Hz, single phase.

Easy maintenance – Non-volatile memory with SIGNATURE records eight of the most recent Serious (Hard Fault) Protection events.

Documentation – The User's Manual is available as a PDF file only. The latest version is available under the Download tab (see above). ACOM creates and distributes its documentation in ENGLISH language only.

ACOM 1003 Amplifier Specifications:

Frequency Coverage

• All amateur bands in the 1.8-54 MHz frequency range:

  • 1.800 - 2.000 MHz (160 m band)

  • 3.500 - 4.000 MHz (80 m band)

  • 5.250 - 5.450 MHz (60 m band)*

  • 7.000 - 7.300 MHz (40 m band)

  • 10.100 - 10.150 MHz (30 m band)

  • 14.000 - 14.350 MHz (20 m band)

  • 18.068 - 18.168 MHz (17 m band)

  • 21.000 - 21.450 MHz (15 m band)

  • 24.890 - 24.990 MHz (12 m band)

  • 28.000 - 29.700 MHz (10 m band)

  • 50.000 - 54.000 MHz (6 m band)* (*) Please refer to the applicable regional band plans and regulations for specific frequency allocations and limitations.

Power Output

• 1000 W PEP or 900 W continuous carrier, with no limitation to the operating mode

• In continuous carrier modes (RTTY, FT8, etc.) when operating for greater than 5 minutes, an external auxiliary fan must be mounted and run.

Intermodulation Distortion at rated power

• Better than 34 dB IMD₃ with regard to one of the two tones (40 dB below PEP).

Hum and noise

• Not more than 4,5% (-27 dB) AM depth at rated power.

Harmonic Emissions Output Suppression

• 1.8-29.7 MHz - better than 50 dB below rated power.

• 50-54 MHz - better than 70 dB below rated power.

Input and Output Impedances

• Nominal impedance: 50 Ω unbalanced, UHF / PTFE coaxial connectors (SO-239A).

• Input circuit: factory tuned low-pass filters for best linearity and input SWR not more than 1.3 in every amateur band from 160 m to 6 m.

• Bypass path SWR: not more than 1.1 continuously from 1.8 to 54 MHz.

• Minimum range of impedance matching capability at the output: all loads with SWR up to 3* at any phase angle. (*) The drive power must be reduced at SWR above 3 in order to keep the Reflected Power under 250 W.

HF Power Gain

• 12 dB ±1 dB (50 W - 80 W at the input for rated output power).

Mains Power Supply Voltage

• 90-132 VAC / 180-264 VAC (taps for 8 nominal voltages: 100, 110, 120, 200, 210, 220, 230 & 240 VAC, ±10% tolerance), 50-60 Hz, Single phase.

Mains Power Consumption

• 2000 VA at 240 VAC.

Safety and Electromagnetic Compatibility

• Complies with European Union's CE safety and electromagnetic compatibility requirements.

• Complies with the US Federal Communications Commission (FCC) regulations - FCC Identifier: 2AJXZ1003, Date of Grant: 03 June 2025.

Size & Weight (operating, excluding connected cables)

• WxDxH: 423x398x195 mm, 21.0 kg (16.7x15.7x7.7 inches, 46.3 lbs.).

Shipping Size & Weight

• WxDxH: Approx. 632x583x413 mm, 25.0 kg (24.9x23.0x16.3 inches, 55.1 lbs.).

Operating environments

• Temperature range: 0 to +50 degrees Celsius (32 degrees F to 122 degrees F).

• Relative air humidity: up to 95% at +35 degrees Celsius (95 degrees F).

• Height above sea level: up to 3050 m (10000 ft) without output deterioration.