This is a PCB-design + Arduino firmware for an Ethernet-controlled 1:8 RF-multiplexer. It allows selecting as output one of eight input-channels, as commonly used e.g. in timing-laboratories when one wants to measure many RF-sources (clock outputs like 1PPS or 10MHz) with a single instrument (frequency or time-interval counter). The design is for two independent MUX-boards to fit in a 1U 19” rack enclosure. For more information, see the wiki