Acom 04AT

Remote 1.5kW Auto ATU and four way Antennas switch

SKU: ACOM 04AT Category: Feature: Brand: Awaiting Stock



  • 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 305m 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.
  • 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.
  • 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 gas filled discharger; unused antennas are directly grounded during operation as well as all antennas 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 impedance’s with 50 Ohm-SWR between 1 and 3; (for some higher-SWR impedance’s matching is also possible – see power limitations below).

Maximum RF Input power admissible, average or continuous (no mode limitations; in brackets – PEP):

  • At antenna SWR below 2:1500W (1500W PEP);
  • At antenna SWR between 2 and 3:1200W (1500W PEP);
  • At antenna SWR between 3 and 5 (provided matching is possible): 700W (1000W PEP);
  • At antenna SWR between 5 and 10 (provided matching is possible): 350W (500W PEP);

Operation at SWR above 10 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 1.8;
  • Input SWR soon after full tuning: less than 1.5 (below 1.3 typ.).
  • Antenna output characteristics:
  • Nominal impedance: 50-Ohm unbalanced;
  • Connector type: UHF/PTFE (S0239A);
  • Number of outputs – 4;
  • Antenna SWR: between 1 and 3 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.
  • Fast tuning duration: less than 50ms (from nonvolatile memory).

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):

  • 61 m (200 feet) for cable type RG-58;
  • 305 m (1000 feet) for cable type RG-213.

ATTENTION! In order to keep possible RF loss at a minimum, use only the minimum length needed to install the ACOM 04AT tuner and switch as close to the antennas as practical.

  • Size and mass (operating) W 510 mm x D 400 mm  x H 300 mm (11.8); 7.0 kg (15.43 lbs).

Operating environments:

  • Weather protection: IP 53 (NEMA Type 3);
  • Temperature range: -40 to +65 degrees C (-40…+150F)

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