AUI to thick ethernet transceiver designed to connect to network cards with an AUI 15 pin D socket. This interfaced to a 50 Ohm coaxial cable via N-type coax connectors and provided a connection “Drop”.

The correct name for this is a Medium Attachment Unit.

The transceivers are powered from a source in the network card, the tx and rx connections are over a twisted pair.

The card on the right is an old 3Com one, it has from bottom to top, a thin ethernet BNC socket (10Base-2), and AUI port for connecting to the 3C108 transceiver (Using a 15pin D plug to 15pin D socket, 3 sets of twisted pairs, Tx, Rx and power) and at the top, a 10Base-T RJ45 connector.

Two basic versions of thick ethernet taps were produces, this on is an example of where the Yellow Coax cable has to be severed and an N connector plug crimped or soldered to each end, these are then screwed in to the tap.

The other type used a sharp pin to pierce the cable and could be installed without interruption to service, these were often referred to as “Vampire Taps”.

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