Description
HF Automatic Antenna Tuner for Marine and Land Mobile Transceivers
Advanced weather-resistant antenna matching network engineered for 150W single sideband (SSB) communications.
The Icom AT140 is an authentic original equipment manufacturer heavy-duty automatic antenna tuner designed to deliver rock-solid impedance balancing across oceanic and remote land terrain environments. Engineered to connect with high-class marine single sideband (SSB) and commercial base transceivers, this high-performance system handles up to 150 Watts PEP of input power. The Icom AT140 HF (1.6-30MHz) Automatic Antenna Tuner enables operators to quickly match long-wire, backstay, or vertical whip antennas measuring 7 meters (23 feet) or longer, ensuring peak power transfer efficiency and a safe voltage standing wave ratio (VSWR) across challenging operations.
Housed in a durable, completely weather-resistant acrylic case fitted with custom internal rubber gaskets, this marine-grade system can be installed externally near the base of the antenna element to minimize RF transmission line loss. Controlled by an advanced central processor, the unit rapidly runs automated matching cycles in roughly 2 to 3 seconds. For extreme convenience when alternating channels, the tuner features an integrated non-volatile electronic memory array capable of caching previous configurations for up to 45 unique frequencies, enabling rapid 1-second re-tuning when returning to an established band.
To preserve strict channel hygiene and prevent active interference with neighboring channels, the tuner implements a specialized low-power tune-up system that radiates only 300mW of RF energy from the antenna during active matching routines. The unit features built-in pass-thru tuning capability and pre-wired connection blocks to simplify hardware field terminations. This outdoor component draws its entire 13.6V DC operational power supply lines straight from the connected host radio via a shielded data control cable, bypassing any need for a distinct external power wire run. Operators should note that the physical long-wire antennas, copper grounding foil systems, linear high-power amplifiers, and core desktop transceiver decks are sold separately.
Key Features & Benefits
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Wide Range HF Coverage: Automatically matches frequencies across the 1.6 MHz to 30 MHz range when connected to an antenna element 7 meters or longer.
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Weatherproof Acrylic Casing: Engineered with a heavy-duty gasket-sealed outer shell to repel heavy rain, high humidity, salt spray, and oceanic environment stress.
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45 Frequency Auto-Memories: Recalls matching parameters instantly from onboard memory blocks to drop re-tuning times to roughly 1 second.
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Ultra-Low Tuning Radiation: Emits a minimal 300mW RF footprint during setup to safeguard spectrum clarity and block interference with other vessels.
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Pass-Thru Tuning Integration: Retains a bypass pathway to ensure continuous basic receiver signal flow even if power pathways are deactivated.
Specifications
| Attribute |
Details |
| Brand |
Icom |
| Model/SKU |
AT140 |
| Product Type |
Automatic Antenna Tuner |
| Frequency Segment |
HF (1.6 – 30 MHz) |
| Maximum Input Power |
150 Watts PEP / 100 Watts Continuous |
| Input Impedance |
50 Ohm (SO239 Female Coaxial Terminal) |
| Tuning Power Required |
5 – 15 Watts (Nominal Rated) |
| Tuning Speed |
2 – 3 Seconds Average (15 Seconds Max) |
| Re-tuning Speed |
Approximately 1 Second (Memorized Channel) |
| Tuning Accuracy |
VSWR 2.0:1 or Better |
| Memory Capacity |
45 Onboard Saved Frequencies |
| Power Supply Requirement |
13.6V DC (Supplied Directly from the HF Transceiver) |
| Current Drain |
Max 2.0 Amps |
| Case Construction |
Weather-Resistant Sealed Acrylic with Rubber Gaskets |
| Usable Pole Diameter |
32 to 60 mm (1.3 to 2.4 Inches) |
Compatibility
Frequently Asked Questions
Is the primary radio control interface cable included inside this package box?
No, this SKU comprises the automatic antenna tuner hardware and basic mechanical mounting brackets. The necessary multi-conductor shielded control interface lines must be purchased as separate accessories.
Can I mount this antenna tuner on an open deck exposed to ocean water sprays?
Yes, the housing is constructed with an air-tight acrylic shell and moisture-blocking rubber perimeter gaskets specifically designed for exposed outdoor marine mast or bulkhead installations.
What is the absolute minimum wire size needed to operate down to 1.6 MHz?
To tune across the full specified range down through the lower 1.6 MHz band lines, your long-wire antenna or whip configuration must measure a minimum of 7 meters (23 feet) in length.
Does this tuner require an independent marine grounding setup?
Yes, a low-resistance electrical pathway to a heavy ground counterpoise plate, external hull anode plane, or wide copper ground strip is vital to track accurate VSWR levels.
Will this automatic matcher function safely with a 500W commercial power deck?
No, this unit is engineered strictly for 150W-class SSB and HF marine radios. Passing higher wattage tiers through this component will trigger an instant thermal or inductive overload.
Why does the tuner limit its transmission output to 300mW during setup?
Limiting the active tune power to a minimal 300mW baseline ensures that the host radio avoids radiating heavy output spikes, keeping localized marine data frequencies safe from cross-talk.
Warranty
1-year manufacturer’s warranty.
