Description
HF/50 MHz Automatic Antenna Tuner for Portable SDR Transceivers
Compact, weather-resistant outdoor impedance matching system engineered specifically for the IC705 QRP multi-band station.
The Icom AH705 is an authentic original equipment manufacturer automatic antenna tuner engineered to optimize field-deployable portable communication stations. Purpose-built to pair seamlessly alongside the iconic IC705 portable software-defined radio (SDR) transceiver, this micro-sized component delivers fast, effortless matching across the entire HF and 50 MHz spectrum. The Icom AH705 HF/50 MHz (1.8-54MHz) Automatic Antenna Tuner enables multi-band operators to match standard 50-ohm resonant antennas like dipoles and Yagis, as well as unstructured non-resonant long-wire antenna setups, ensuring optimal power transfer and a safe voltage standing wave ratio (VSWR) metric under variable field environments.
Built to sustain rugged tactical and outdoor deployments, the compact chassis features an IP54-certified dust-protected and splash-resistant construction matrix to shield delicate internal matching circuits from ambient moisture. The unit is designed with power-saving latching relays that draw power only during active tuning cycles, dropping standby battery consumption to near zero. For total field deployment independence, the tuner incorporates a dual-mode power architecture, allowing it to run smoothly off two internal AA alkaline dry cells or receive clean external 13.8V DC power directly from an independent base battery pack.
Operators should note that this portable system is a specialized low-power QRP accessory rated to handle a maximum RF power threshold of 10 Watts PEP. Attempting to pass high-wattage desktop base amplification through this unit will cause immediate internal hardware failure. The standalone portable SDR transceiver chassis, external base station linear amplifiers, long-wire antenna wire spools, and secondary multi-unit replacement rechargeable battery packs are sold separately.
Key Features & Benefits
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Wideband Impedance Coverage: Automatically tracks and matches frequencies from 1.8 MHz to 54 MHz using long-wire or dipole elements.
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One-Touch Radio Integration: Initiates full electronic tuning cycles instantly at the press of the native [TUNER] button on the host transceiver control panel.
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IP54 Weatherized Integrity: Protected by sealed outer housing skins and rugged terminal jack covers to repel dust storms and moisture splashes.
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Low-Power Latching Relays: Utilizes state-of-the-art internal latching relays to eliminate continuous electrical drain between active transmission periods.
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Dual Power Delivery Paths: Features a versatile power grid accepting either two standard AA batteries for lightweight portables or direct 13.8V DC input lines.
Specifications
| Attribute |
Details |
| Brand |
Icom |
| Model/SKU |
AH705 |
| Product Type |
Automatic Antenna Tuner |
| Frequency Band |
HF / 50 MHz (1.8 – 54 MHz) |
| Max Input Power |
10 Watts PEP |
| Input Impedance |
50 Ohm |
| Tuning Power Req. |
5 Watts / 10 Watts |
| Tuning Speed |
2 – 3 Seconds Average (15 Seconds Max) |
| Tuning Accuracy |
Less than 1: 2.0 VSWR |
| Internal Memories |
45 Tuned Channels |
| Power Sources |
2x AA Alkaline Batteries or External 13.8V DC (±15%) |
| Current Drain |
< 300 mA (Tuning) / < 1 mA (Standby) |
| Ingress Rating |
IP54 Dust and Water Resistant |
| Interface Ports |
BNC (RF In) / SO239 (Antenna Out) / 3.5mm (Control Link) |
Compatibility
Recommended Accessories
Frequently Asked Questions
Are the AA batteries for this tuner included with the packaging?
No, this product listing is for the automatic tuner assembly and installation wiring hardware. The two required AA alkaline cells must be acquired separately.
Can I supply external DC power to this tuner from the IC705 radio?
No, external 13.8V DC current must be pulled directly from a dedicated standalone external power supply distribution line, never through the IC705 accessory sockets.
Is this tuning unit compatible with high-power 100-watt hf transceivers?
No, this unit is engineered strictly for low-power QRP field operations and has a hard ceiling capacity limit of 10 Watts. High-power inputs will damage internal components.
What type of antenna wire is required to tune down to the 1.8 MHz band?
To operate reliably down into the 1.8 MHz segment, you must deploy a long-wire antenna element measuring at least 30 meters (98.4 feet) in total length.
How many distinct tuning channel frequencies can the internal memory retain?
The onboard processor contains non-volatile electronic memory blocks calibrated to store up to 45 separate unique matched configurations to reduce repeat tuning times.
Does this tuner protect the radio if the VSWR is too high?
Yes, it communicates directly via the control cable to verify proper matching lines, allowing the transceiver to monitor final safety limits before full power transmission.
Warranty
1-year manufacturer’s warranty.
