An antenna tuning unit, ATU or antenna tuner is an item consisting of inductors and capacitors that is used to tune an antenna so that it matches the feeder and reduces the SWR.
This does not signal a problem with temperature or SWR. E. Pre-emphasis. Use this jumper to set pre-emphasis. This can either be 50uS (EU and most of the world) or 75uS (USA). If you plan to connect stereo encoder to the MAX PRO 3+ board, remove the jumper (this disables pre...