ATU-100 Antenna Tuner
Antenna Tuner, designed by N7DDC, 1.8-50MHz, up to 100 Watts. Bought for 97€ in 12/2021.
OLED display and tune button
Power switch, power supply connector, antenna and TX input connector
15 relais…
The PIC16F1938 microcontroller
References
ATU-100 Extended Board User Manual
https://github.com/Dfinitski/N7DDC-ATU-100-mini-and-extended-boards
http://oe1iah.at/Hardware/AutoTuner_ATU100.shtml
Large thread on QRPForum.de (german) - https://www.qrpforum.de/forum/index.php?thread/13177-auto-antennentuner-nach-n7ddc/&pageNo=1
ATU-100 mini original thread (russian) http://www.sdr-deluxe.com/forum/7-17-1