ATU-500W Automatic Antenna Tuner (HP improved version of ATU-100)

Product Name: 1.8-50 MHz Compatible ATU500W Automatic Antenna Tuner
ATU-500W by N7DDC
Accessories: DC power plug, simple instruction manual (English), original box
Purchase Date: July 2025, from online retailer in China
Maximum Operating Power: 500 W
My Usage: SSB 200W or less, FT-8 100W or less
Dimensions: 13.5 x 7.5 x 25 cm
Weight: 1.2 kg

Various usage guides are available on YouTube.

・Strictly adhere to 10W-30W during tuning.
・After tuning, you can increase the output for operation. However, in automatic mode, if the SWR increases during transmission, it will re-initiate tuning, so be mindful of the output power. For peace of mind, use the sequence: Bypass > Reset > Tune.
・Tunes to 1.5 or below in 2-3 seconds. However, it may not tune down if the SWR is too high. By combining capacitors and coils, it will drop to the 1.0 range when the transmission frequency matches. Adjusting it can be quite enjoyable.
・A reset is required when changing bands.
・Caution is advised for FT-8 output as it's not specified (around 100W or less?).
・I believe it is in beautiful condition as it has not been used much.

Information from the sales site below:
Materials:
Uses low-loss, low-temperature rise T130-2EW for the magnetic ring, and German BASF 6000 mesh 1-3 micron iron powder core for the material. Performance is improved compared to T130.
Parameters:
- Frequency Range: 1.8 - 50 MHz
- Power Supply Range: 10 - 15 VDC
Note: Recommended maximum power during tuning is 30 watts or less (after tuning, you can increase the wattage to operate at this power. Otherwise, it may burn out).
- Maximum Operating Power: 500 Watts
- Minimum Power for Tuning Start: 10 Watts (tuning may be insufficient at 1-10W)
- Minimum Measured Power: 10 Watts
- Measurement Step for Power below 10 Watts: 0.1 Watts
- Measurement Step for Power above 10 Watts: 1 Watt
- Power Measurement Accuracy: 10%
- Maximum Inductance Setting: 8.5 uH
- Minimum Step for Inductance Setting: 0.1 uH
- Maximum Capacitance Setting: 1870 pF
- Minimum Step for Capacitance Setting: 10 pF