Acom 04AT Remote Automatic Antenna Tuner and Switch

  • Fully Automatic Remote ATU
  • Integral 4 way antenna switch
  • 1.8-30MHz and 50-54MHz
  • Integrates with Acom SSPA’s
  • Outdoor rated
  • Powered and controlled via the coax feed

Price excl VAT: £915.83
incl VAT: £1,099.00

2 in stock (can be backordered)


ACOM 04AT is a remote automatic antenna tuner for HF + 6 m with integrated four-way antenna switch. The tuner automatically selects one of four available antenna outputs (as assigned in bands by the operator) and matches the impedance of the chosen antenna output by transforming it to 50 Ohm with SWR below 1.5:1 at the tuner input (typically below 1.3), providing an optimum load impedance for the amplifier.

The ACOM 04AT tuner is specifically designed and developed to work with the ACOM series of solid state (transistor) amplifiers, e.g., ACOM 500S, 600S, 700S, 1200S or ACOM 2020S.

Easy set-up of user tuning presets
For a CAT transceiver a single press of the TUNE button on the amplifier front panel is all you need.

Transparent (invisible) operation
After setting up the user presets (auto tune) for the frequency segments and antennas, the operator will not be involved with tuner operation.

Three kinds of frequency segments, according to antenna bandwidth
The operator can choose according to the nature of each of the four antennas: Narrow band – Sharp, Normal – Regular, and Broadband – Wide) Also capable of operation at fixed frequencies

Non-volatile memory
Non-volatile memory for user presets (auto tune), independent for the four antennas, the three types of segment width, and more than 1000 random fixed frequencies for each antenna.

User presets
The user presets are automatically loaded, following frequency and antenna selection changes.

Export (backup) of preset memory
Backup of preset memory to a computer file, import of previously made backup files from a computer to the tuner memory.

Helpful information
Information about the setting age, and alerts for settings that reach a certain age, defined by the operator in 4 possible age levels.

Power supply and control to the tuner
Power supply and control to the tuner, as well as status return from the tuner are supplied over the coaxial cable between the amplifier and tuner, there is no requirement for additional cables or special control signals from the transceiver (the availability of CAT control from the transceiver will give further advantages to the setup).

Improved electromagnetic compatibility
Full tuning can be completed within 5 seconds (typically 2-3 seconds), at 25 W at the tuner input and less than 6 W at the antenna output; quick tuning (from nonvolatile-memory presets) is completed in less than 0.05 seconds with zero emitted signals.

Input SWR during full tuning cycles
Input SWR during full tuning cycles – below 2:1, preventing activation of transceiver PA protection.

Input SWR after completing a tuning cycle
Input SWR after completing a tuning cycle – below 1.5:1 (typically below 1.3:1).

Relays with gold-plated contacts
Relays with gold-plated contacts for excellent receive characteristics.

Relay switching
Relay switching will only take place when no RF current is flowing, preventing contact arcing critical to preventing contact oxidation, surface melting and material transfer (otherwise resulting in poor receiving performance) and to avoid any unwanted widening of the spectrum of signals, emitted during the tuning cycle.

Air-core coils and high-quality ceramic capacitors
Air-core coils (no magnetic materials) and high-quality NP0 (C0G) ceramic capacitors usage throughout the matching circuit.

Harmonic suppression
The matching network is a low-pass L filter naturally improving harmonic suppression.

Remote installation
Allows remote installation, including outdoors, close to the antenna feed point, minimizing losses.
ACOM 04AT can be located up to 100 m (330 ft) away from the shack.

Integrated antenna switch
Integrated four-way antenna switch – less coaxial cable, shorter unmatched sections, less losses.

Automatic and manual antenna switching
Antennas can be automatically and manually switched from the amplifier front panel. The last used antenna selection is memorized.

Customized antennas names and types
Indication and editing of names and types of antennas in editable freeform.

Protection mechanisms
Various protection mechanisms, including: antenna overvoltage, antenna overcurrent, excessive power during operation and tuning, extreme temperatures and power supply voltages, as well as relay hot-switching.

Safe power supply
Safe low power supply voltage (26 VDC).

In BYPASS mode all components of the matching network are excluded, allowing direct operation of broadband antennas.

This menu allowing analysis of the tuner status and review of the used resource of coils and capacitors for all memorized and current tuning presets.

Lightning arrestor and bleeder resistor
Integrated lightning arrestor and bleeder resistor for protection against static discharges; automatic grounding of antennas on powering off.


WxDxH: 345 x 250 x 190 mm, 4.2 kg (13.6×9.9×7.5 inches, 9.3 lbs.)