The Icom AH-4 automatic antenna tuner is designed to work with select ICOM transceivers 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). 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.
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: 7 x 2.9 x 9.2 inches 2.65 Lbs. (172x70x230mm 1.2 kg).
Best External Icom Tuner
This is a rugged longwire tuner (it will do a loop as well ) that can match a 102 inch whip to a 132 foot longwire quickly and efficiently. Primarily designed for mobile use, many HOA restricted and apartment dwellers are making QSOs with this and a random wire. It does need a decent counterpoise. Plugs right into your Icom radio with the 4 pin connector. If you want to take your 7300 or 7100 out in the field then this will match the longwire that the built in tuner may struggle with. Works as well on a power boat as well