Arduino Mega 2560 Code with a standard Ethernet Shield that drives Relays to control a MFJ-993b Autotuner remotely.
Supports Up and Down for manual L and C Tuning, Autotune On/Off, Antenna Selection 1/2 and 100ms Short /1000ms Long for Tune.
Op Note 1: You may need additional power for the 5V relay board; sometimes you can power the 5V relay board from the Mega 2560 - but reset/start the device first and then connect power to the relay board.
Op Note 2: You will need determine pinouts to the MFJ-993b DB9 yourself. ...