Features: brand new and high quality ● Connect the radio-ATU antenna tuner-antenna ● If the SWR of the ATU antenna tuner shows greater than 2.0 in the transmission state, it means that the antenna has been detuned. You need to use an antenna tuner. Press and hold the ATU button TUNE to tune and observe the SWR value. If the SWR is greater than 3.0 after tuning, the antenna will be detuned. Seriously, it is not recommended to use a power above 30W, and the transmission power should be controlled below 30W; if the tuning is completed, the SWR display is less than 2.0, and the maximum power of 100W can be used for transmission ● Select the antenna frequency band to be used, use 20-30W power in FM mode, press the radio PPT, observe the ATU antenna tuner PWR and SWR ● Set radio mode, use FM mode ● The use of ATU button TUNE: Short press (less than 1 second) ATU button, it is in reset state, long press (more than 1 second) ATU button is in adjustment state ● When using it for the first for time, please set the output power of the radio or power amplifier between 20-30W, warning that high-power tuning may easily damage the antenna tuner. Specifications: Material:Metal Maximum working power: 100 watts Maximum possible measured power: 150 watts 1 watt: It is necessary to start setting the minimum power The smallest possible measured power: 0,1 watts Measurement procedure with power up to 10W: 0, 1 watt Hourly powerful measurement steps 10 watts above STI: 1 watt Power measurement accuracy: 10% Specified maximum inductance: 8,4 uH capacity Minimum installation step length of inductance: 0.05μH Maximum installation capacity: 1870 pF capacitor Minimum installation step length: 10 Package Includes: 1PcxAntenna Tuner 1PcxWire note: 1.Please allow 1-2mm errors due to manual measurement, make sure that you do not mind before you order. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item.