ACOM 04AT | Remote Automatic Antenna Tuner and Switch

ACOM 04AT | Remote Automatic Antenna Tuner and Switch

  • Remote matching of antennas - less losses in the feed line. Designed for installation in a shack, under a shed, or in open (see mounting kit options). Can be distanced up to 100 m (330 feet) from amplifier.
  • Powered and controlled directly from the ACOM solid state HF+6m amplifiers through the amplifier RF output cable only - there is no need for power or control cables between the shack and the tuner.
  • Provides automatic or manual antenna change and automatic antenna impedance matching to the ACOM solid state HF + 6m amplifiers, controlled entirely from the amplifier front panel and your transceiver CAT.
  • Guards the transceiver and amplifier against excessive impedance mismatch during the tuning process.
  • Operates with two types of tunings: full tuning (basic matching cycle) and fast tuning (retrieving user tuning patterns from nonvolatile memory.
  • Full tuning is 100% automated however a cycle is initiated only by the operator. User tunings track the antenna and frequency changes automatically during amplifier and transceiver operation.
  • Four typical antenna types: Regular, Sharp, Wide, and Fixed-frequency are available so the operator can adapt the frequency segment width to the specific antenna bandwidth; BYPASS mode is also available.
  • Antennas appear with a number, type, and user-editable name on the ACOM solid state amplifiers screen.
  • Tunings availability presented by a graphic scale on the ACOM solid state amplifiers screen.
  • A plenty of antenna- and tuner- related information is available on the ACOM solid state amplifier screen: menus ATU SERVICE, ATU MEASURE, ATU TUNINGS LOOKUP/ERASE, Resource-estimate function etc.
  • Tuning “age” warning can be set to warn you when you attempt to use an outdated tuning.
  • The user can archive all tunings from nonvolatile memory in a computer file as well as upload earlier archived files in the ACOM 04AT nonvolatile memory through the ACOM solid state amplifier’s RS232 port.
  • Protections: PS voltage, Reverse PS polarity, Excessive RF voltage, RF current or reflected power at the antenna outputs, Excessive tuning power, Excessive Input power, Hot switching of relays, Overheating etc.
  • Protected against building of static electricity in the antennas via bleeding resistors and against close lightning strikes via gasfilled discharger; unused antennas are directly grounded during operation as well as all antennas are when the ACOM 04AT is powered off.
  • Frequency coverage: 1.8 to 30MHz and 50 to 54MHz, continuously (30 to 50MHz on request).
  • Antenna impedance matching capability: all impedances with 50 Ohm-SWR between 1:1 and 3:1; (for some higher-SWR impedances matching is also possible see power limitations below).
  • Maximum RF Input power admissible, average or continuous (no mode limitations; in brackets - PEP):








Pin, W







* (when tuning is possible for SWR above 3:1)

  • Rem: Operation at SWR above 10:1 is not permitted even though matching could be possible in some cases.
  • RF Input characteristics:

-Nominal impedance: 50-Ohm unbalanced;

-Connector type: UHF/PTFE (S0239A);

-Input SWR during full tuning (basic matching cycle): below 2:1

-Input SWR soon after full tuning: less than 1.5:1 (below 1.3:1 typ.).

  • Antenna output characteristics:

-Nominal impedance: 50-Ohm unbalanced;

-Connector type: UHF/PTFE (S0239A);

-Number of outputs - 4;

-Antenna SWR: between 1:1  and 3:1 for 100% matching, full power; for higher-SWR impedances (provided matching is possible) see power limitations above).

  • Full tuning duration (basic matching cycle):

-Below 10MHz: less than 5s (2-3s typ.)

-Above 10MHz: less than 3s (1-2s typ.).

  • RF Input power required during full tuning: 25W +3/-3 dB (12.5 to 50 W), non-modulated.
  • Power supply and control: available from the ACOM solid state HF+6m amplifiers through RF-output coaxial cable; +26VDC, up to 25 W consumption; control data using a FSK modem at 60 kHz.
  • Coaxial cable maximum length (same for RF power, DC power supply, and control):

-100 m (330 feet) for cable type RG-213.

Size and mass (operating)

- Width: 345mm (13.6”)

- Depth: 250mm (9.9”)

- Height: 190mm (7.5”)

- Mass: 4.2kg (9.25lbs).

  • Operating environments:

-Weather protection: IP 53 (NEMA Type 3);

-Temperature range: -40 to +65 degrees C (-40...+150F);

-Humidity: up to 98% @ +40 degrees C (104F);

-Height ASL without parameters deterioration: up to 3050 m (10 000 feet).