Product Overview

mAT-125E Universal Automatic Antenna Tuner

The mAT-125E is a versatile automatic antenna tuner that can be used with almost all types of transmitters. It provides automatic antenna tuning across the entire HF spectrum plus 6 meters, at power levels up to 120 watts. It will tune dipoles, verticals, Yagis, or virtually any coax-fed antenna. The mAT-125E will match an amazing range of antennas and impedances, far greater than some other tuners you may have considered, including the built-in tuners on many radios.

The mAT-125E does not require a control cable to be connected to the transceiver. It only needs an RF cable to function properly, making installation quick and simple.

Key Features

mAT-125E Features

The mAT-125E features 16,000 frequency memories. When tuning on or near a previously tuned frequency, it uses "Memory Tune" to recall previous tuning parameters in a fraction of a second. If no memorized settings are available, the tuner runs a full tuning cycle, storing the parameters for memory recall on subsequent tuning cycles on that frequency. In this manner, the mAT-125E "learns" as it is used, adapting to the bands and frequencies as it goes.

Built-in Lithium Batteries

The mAT-125E tuner has two built-in high-capacity 18650 lithium batteries and uses magnetic latching relays. This design eliminates the need for an external power supply and allows the tuner to operate for a very long time when fully charged. Under normal use, it typically does not require recharging for several weeks.

Charging Information

The tuner is designed with a standard USB Type-C charging interface. No charger is included; a charging cable is provided. Users can conveniently charge it using a mobile phone charger. The charging voltage is 5 V with a maximum current of 1 A.

Important: Before first use, and again after reinstalling the lithium batteries, be sure to connect the charger and charge the tuner first to activate the internal lithium battery protection circuit. Otherwise, the tuner will not operate.

Front Panel Controls

mAT-125E Front Panel

The front panel of the tuner features 4 indicator lights and 6 buttons for comprehensive control and status monitoring.

1.5, 2.0, 3.0 Indicators

Show current SWR and operational status. Flashing patterns indicate different modes and functions.

PWR Indicator

Green when tuner is working, red when charging, flashes rapidly when battery is depleted, and turns off when battery is fully charged.

[TUNE] Button

Initiates tuning cycle, switches between Online/Bypass states (also by quick press), multifunctional key.

[CUP] / [CDN] Buttons

Manually increase/decrease capacitance for fine tuning.

[LUP] / [LDN] Buttons

Manually increase/decrease inductance for fine tuning.

[POWER] Button

Power on/off key.

Button Combinations:

  • [TUNE] + [CDN]: Switch between Online/Bypass states
  • [TUNE] + [LUP]: Manually save current tuning network data to memory
  • [TUNE] + [LDN]: Switch between Automatic/Semi-automatic modes
  • [TUNE] + POWER ON: Enable/disable Auto-Shutdown function

Note: [A] + [B] means first press and hold [A], then press [B], then release both.

Rear Panel

mAT-125E Rear Panel

Rear Panel Connectors:

  • GND: Connect to antenna system ground for optimal performance and safety
  • ANTENNA: SO-239 socket for antenna connection using 50 ohm coaxial cable
  • RF IN: SO-239 socket connected to transmitter's "ANT" socket
  • CHARGER: Type-C USB socket for charging (4.5-5.5V, less than 1.0A)

Operation Modes

Automatic Mode:

When RF signal is input, the tuner verifies power is within predefined range (1-20W). If within range, it captures a signal sample, measures frequency, checks memory for previous tuning data, sets the tuning network, measures VSWR, and displays results. Tuning cycle only initiates when [TUNE] is pressed if SWR is high.

Semi-automatic Mode:

When RF signal is input, the tuner measures and displays current VSWR. Tuning cycle only initiates when [TUNE] is pressed. After pressing [TUNE], it measures frequency, retrieves configuration from memory, configures LC network, and measures VSWR. If VSWR < 1.5, tuning completes; if higher, new tuning cycle starts.

Manual Tuning:

In either mode, you can fine-tune the LC network using [CUP], [CDN], [LUP], and [LDN] buttons. After manual adjustment, save the configuration to memory using [TUNE]+[LUP].

Technical Specifications

Frequency Range 1.8 - 54 MHz
Maximum Input Power 120W (SSB), 30W (DATA)
Tuning Power Required 0.5-15W
Tuning Time Maximum 5 seconds (Full tuning)
0.1 seconds (Memory tuning)
Battery Two 18650 lithium batteries, 3.7V, 2000mAh each
Charging Type-C USB, 4.5-5.5V, 1.0A
Operating Temperature -10°C ~ +60°C (14°F ~ 140°F)
Memory Channels 16000
Dimensions 200 x 130 x 35 mm (7.9 x 5.1 x 1.4 inches)
Weight 800g (28.2 oz)
Construction Metal shell with aluminum milling panel

Supplied Accessories

Type-C Charging Cable - Standard accessory

Auto-Shutdown Function

The tuner features an energy-saving auto-shutdown function. When activated, the tuner will automatically turn off if no button is pressed for approximately 3 minutes. Since the tuner uses magnetic latching relays, the current tuning state is preserved even after shutdown.

Technical Support

Visit our website: http://www.mat-tuner.com/ for more information, product manuals, specifications, and photographs. Our website also provides links to authorized MAT-TUNER dealers ready to assist with your purchase decisions.

(Note: The pictures on this page are for reference only. The actual products received are the basis.)