This popular TECHOMAN ATU-100 is an automatic antenna tuner based on the well-known open-source project by N7DDC. It's designed for HF transceivers and is designed for use for portable operations (POTA/SOTA), mobile or low power temporary base station use.
Important Usage Tips
To keep your gear in top shape and ensure you’re covered by your warranty, please keep the following in mind:
- Watch the Watts: Never exceed 20W while the tuner is actively seeking a match. High power during the tuning process can damage the internal components and circuit board.
- The "Perfect" Match: Tuning aims to significantly improve your SWR for safe operation, though it may not always reach a flat 1:1.
- Best Fit: This unit excels at tuning antennas that are already near-resonant or harmonics of your target frequency.
If you’re working with a non-resonant "wet noodle" antenna or high-impedance wires, we recommend checking out our range of Manual tuners and Automatic Tuners available here at Techoman.
General Specifications:
- Frequency Range: 1.8 – 54 MHz (covers all amateur HF bands plus 6m)
- Maximum Working Power: 100 Watts Peak (SSB/CW)
- Tuning Power: 10 Watts required to trigger an auto-tune)
- Maximum Tuning Power: 20 Watts (Do not exceed this during the tuning process to avoid internal component damage)
- Minimum Measured Power: 0.1 Watt
Hardware & Power:
- Display: 0.91-inch or 0.96-inch OLED (Monochrome).
- Internal Battery: Typically includes a 3.7V / 1800mAh Lithium-ion battery.
- Charging: Micro-USB port (visible on the front panel).
- Current Consumption: 100–400 mA (during tuning); negligible in standby.
- Case Material: Aluminium alloy.
Operational Modes:
- Automatic Mode: Triggers tuning when the SWR is detected above a set threshold (usually 3:1).
- Manual Mode: Tuning is initiated by a long press of the green TUNE button.
- Reset: A short press of the TUNE button resets the relays to a "straight-through" (bypass) position.
Technical Note:
To ensure longevity, it is recommended to drop your transceiver's power to 10-20 Watts while the tuner is actively clicking through its relay cycles, then increase to your full 100 Watts once the "TUNE" indicator on the screen stops.
Please Note: Be very careful when tuning (keep to 10-20 watts) and once tuned maximum of 100 watts. Warranty is void if the ATU is opened, tuning has been undertaken at power above 20 watts or if the circuit board and/or components on the circuit board are burnt or damaged with too high power input .