vampire tap
The classic Ethernet according to 10Base-5 had the bulky Yellow Cable as transmission medium. For the direct connection of a transceiver to the Terminal Access Point( TAP), a hole was drilled in the cable, which reached up to the center conductor.
Through this hole, the transceiver's contact pin made contact with the center conductor. The ground connection of the transceiver was then made to the outer shield of the Yellow cable by claws that cut through the outer insulation. This connection technique was accomplished with vampire clamps.
As an alternative to the vampire clamp technique, it was necessary to cut the Yellow Cable, install an N- connector tee, and make the transceiver connection via a T-connector.