K3NG was working on an open-source Arduino-based ATU, but I am not sure what the current status is : http://blog.radioartisan.com/arduino-antenna-tuner/
Built with an Arduino nano it could be quite small.
I would like to ask over here if someone can let me know what are some inexpensive automatic antenna tuners that can be built into the transceivers with lack of ATU please?
Thank You a lot,
73 - Petr, OK1RP