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Provides reliable matching from 1.8 MHz to 54 MHz with specific antennas.
Utilizes a microprocessor for optimal SWR selection via LC combinations.
Automatically memorizes previously used frequencies for fast tuning (<1 second).
Radiates less than 0.3 W during tuning, minimizing interference.
Tightly sealed case allows versatile mounting, including outdoors.
Defines hazard levels (DANGER, WARNING, CAUTION, NOTE) for safety.
Critical safety warnings regarding grounding, antenna connection, and high voltage.
Details FCC rules for digital devices and potential interference issues.
Instructions for proper disposal of electronic products in the EU.
General safety warnings for installing the antenna tuner and its cables.
Step-by-step guide to ensure a watertight connection at the antenna.
Importance and methods for establishing an adequate ground connection.
Instructions for connecting coaxial and control cables to the transceiver.
Provides methods and safety precautions for mounting the antenna tuner.
Guide on how to tune the antenna tuner for optimal performance.
Technical details including frequency range, power, impedance, and dimensions.
Lists optional accessories like control cables and antenna elements.
The Icom AH-730 is an automatic antenna tuner designed to provide reliable impedance matching for a wide range of HF and 50 MHz transceivers. Its primary function is to optimize the performance of your antenna system by ensuring an efficient transfer of power from the transceiver to the antenna, minimizing reflected power (SWR). This allows the transceiver to operate at its full potential across various frequencies, even with antennas that are not inherently resonant.
The core function of the AH-730 is automatic impedance matching. It employs a sophisticated 32-bit microprocessor that intelligently selects the optimal combination of inductors (coils) and capacitors (LC combinations) from over 1,040,000 possibilities to achieve the lowest possible Standing Wave Ratio (SWR). This digital control ensures precise and rapid tuning.
The tuner is designed to work with a broad frequency range, from 1.8 MHz to 54 MHz, making it suitable for most HF and 50 MHz bands. For optimal performance across this range, it requires a minimum antenna length of 7 meters (23 feet). When paired with the optional AH-2b ANTENNA ELEMENT, the tuning range for the AH-730 extends from 3.5 MHz to 54 MHz.
During the tuning process, the AH-730 minimizes radiated power to less than 0.3 W. This low radiated power is a significant feature, as it helps to reduce potential interference to other nearby stations, ensuring a cleaner operating environment.
The AH-730 offers several features that enhance its usability and convenience:
Fast Tuning with Memory: The tuner incorporates 45 frequency memories. It automatically stores the LC combinations for previously used frequencies. Once a frequency is memorized, the AH-730 can retune to that frequency in less than 1 second. This significantly speeds up operation, especially for frequently visited bands. It's important to note that the tuner does not memorize frequencies that are already tuned within 2.5 seconds, as these are considered sufficiently matched. The memories are retained as long as the tuner has power.
Compatibility: The AH-730 is designed to be compatible with most Icom HF transceivers that cover HF through 50 MHz bands. However, specific models like the IC-706 and IC-736 have a tuning range limitation of 1.8 MHz to 30 MHz when used with the AH-730.
Simple Operation: Tuning with the AH-730 is straightforward, typically initiated from the connected Icom transceiver. For example, with an IC-7300, pressing the "TUNER" button activates or bypasses the AH-730. Holding the "TUNER" button for 1 second initiates a manual tuning cycle, during which the transceiver's display will indicate the tuning status (e.g., "TUNE" blinking red). Once tuning is complete, "TUNE" will be displayed, indicating a successful match. If the tuner cannot achieve an SWR of less than 2:1 within 15 seconds, the "TUNE" indication will go out, and the AH-730 will be bypassed, directly connecting the antenna to the transceiver.
Mounting Flexibility: The AH-730's robust and weatherproof design allows for versatile mounting options. It can be mounted outdoors, directly under the antenna, on an antenna pole using the supplied U-bolts, or on a flat surface using nuts and bolts or self-tapping screws. This flexibility ensures that the tuner can be placed in an optimal location for antenna performance.
While the AH-730 is designed for durability, proper installation and care contribute to its long-term performance:
Weatherproof Design (IPX4): The AH-730 features a tightly sealed plastic case that meets IPX4 requirements for splash resistance. This makes it suitable for outdoor installation, protecting it from rain and splashes. However, it's crucial to avoid immersing the unit in water. If the tuner has been dropped, its splash resistance may be compromised due to potential cracks or seal damage.
Antenna Connection Waterproofing: The manual provides detailed instructions for waterproofing the antenna connection using a weatherproof cap, rubber vulcanizing tape, and electrical tape. This is a critical step to prevent moisture ingress into the connector, which could lead to damage and degraded performance. Following these steps carefully ensures the longevity of the connection.
Grounding Importance: The AH-730 requires a solid ground connection. The ground wire of the antenna tuner acts as an antenna element, and an adequate ground for both the tuner and the transceiver is essential. Proper grounding maximizes overall efficiency, reduces interference, minimizes RF feedback, and prevents electrical shocks. The manual recommends using the heaviest gauge wire or strap available and keeping the connection as short as possible. A long wire connected to the GND terminal can also serve as a counterpoise.
Cable Management: During installation, it's important to handle the control and coaxial cables with care. They should not be modified, bent, twisted, pulled, or heated. Heavy objects should not be hung on them, and they should be secured to prevent pulling or stretching. If RF feedback occurs, connecting the control cable ground to both the AH-730 GND and the transceiver's GND terminals is recommended.
Safe Operation Practices: To prevent personal injury or equipment damage, it is crucial to never operate or tune the antenna tuner without a connected antenna and a solid ground. High voltage is present on the antenna during transmission and tuning, so the antenna should never be touched during these operations and should be placed in a safe, inaccessible position. The tuner should also not be mounted upside down.
By adhering to these installation and maintenance guidelines, users can ensure the AH-730 operates reliably and efficiently for many years, providing excellent antenna matching capabilities for their Icom HF/50 MHz transceivers.
General| Type | Automatic Antenna Tuner |
|---|---|
| Input Impedance | 50 Ω |
| Output Impedance | 50 Ω |
| Power Handling (SSB) | 200 W |
| Power Handling (CW) | 200 W |
| Power Handling (AM/FM/DV) | 100 W |
| Minimum Input Power for Tuning | 10 W |
| Operating Temperature | -10°C to +60°C |
| Frequency Range | 1.8-30 MHz |
| Impedance Range | 16 to 150 Ω |
| Power Supply | 13.8 V DC |
