It provides reliable matching of frequencies from 3.5 to 54 MHz when using a wire of at least 23 feet (7 m) in length. It can also be used for matching 7 to 54 MHz when used with the optional ICOM AH-2b antenna element. The built-in 8-bit microprocessor chooses the lower SWR condition from more than 1,040,000 different LC (coil/capacitance) combinations. The LC combinations of 45 previously-used frequencies are automatically memorized by the AH-4. Once a frequency is memorized, the AH-4 tunes on that frequency is less than one second. (Memories are retained only when the power is on).
The AH-4 is sealed in a plastic weatherproof case for convenient mounting outdoors under your antenna. The transceiver and the AH-4 tuner must have a proper ground connection. Use a short heavy gauge wire or strap for this. This tuner may be attached to a pole using the two supplied U Bolts, or to a flat surface (screws and bolts are supplied). Click here to view mounting examples.
The AH-4 comes with a 16 foot (5 m) control cable that connects to the rear panel of compatible ICOM transceiver. A 16 foot (5 m) raw coax cable and two PL-259s are supplied to connect the transceivers antenna output to the AH-4 antenna input. The PL-259s must be soldered on by the user. Click here to view wiring example.
This tuner requires about 10 watts (5-15 Watts) to activate and can handle up to 120 watts. It operates on 13.8 VDC (less than 2 amps) drawn from the transceiver control cable. Size: 7x2.9x9.2 inches 2.65 Lbs. (172x70x230mm 1.2 kg).
For mobile use (40-6 Meters), add the optional AH-2b (the ICOM AH-2b bumper mount antenna covers 40 to 6 meters. It is 8.2 feet (2.5 m) tall and features a stainless steel spring) whip element (optional).