Key facts
- Brand
- ICOM
- Model
- AH-4
- Category
- Other Electronics
- Documents
- 2
- Languages
- EN
- Last added
- 2026-10-16
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Icom AH-4 Antenna Tuner Operation Guide
The Icom AH-4 is a wide-range antenna tuner designed to match a 50 ohm feed line to antenna feed impedances ranging from 10 to 5,000 ohms. It is capable of operating with up to 120 watts of power and utilizes a microprocessor control system with 22 relays to switch combinations of inductance and capacitance for tuning. The unit features a weatherproof housing suitable for permanent outdoor installation and interfaces with HF radios via a coaxial feed line and a 4-conductor control cable. Key design advantages include a power divider network that keeps the radio's SWR low during tuning and relays that are never switched under power to ensure longevity.
Read onlineIcom AH-4 specifications
| Impedance Matching Range | 10 to 5,000 ohms |
|---|---|
| Maximum Power | 120 watts |
| Tuning Time | 1 to 3 seconds |
| Number of Relays | 22 |
| Operating Voltage | 12 volt |
| Peak Current Demand | Less than one amp |
All Icom AH-4 documents by type
Day-to-day operation, settings and troubleshooting. Start here if the product is already set up.
Questions answered in these manuals
What is the impedance matching range of the AH-4?
The tuner matches a 50 ohm feed line to an antenna feed impedance in the range of 10 to 5,000 ohms.
How long does the tuning process typically take?
The tuning process typically takes between 1 to 3 seconds.
What is the tuning power required for the AH-4?
The tuning power required is between 5 and 15 watts.
From: Icom AH-4 HF + 50 MHz Automatic Antenna Tuner User Manual
Can the AH-4 be used with the IC-706 and IC-736 transceivers?
Yes, but these models can only be tuned in the 3.5-30 MHz range.
From: Icom AH-4 HF + 50 MHz Automatic Antenna Tuner User Manual