Tekprobe BNC connector
The Tekprobe BNC interface was introduced in 1986 and is widely used in 1990s Tektronix equipment to interface active probes (e.g. the P6243) to oscilloscopes.
It consists of a plain BNC connector that allows traditional BNC based connections such as from passive probes.
This connector is surrounded by contact pads carrying power and data. The two larger pad areas match the simple resistive readout pins on probes from the 7000 series scope generation (e.g. a ×10 probe will connect this pad to ground through 11 kΩ, or short it to ground when the Identify button is pressed — see 7000 series readout system for details). The smaller pads carry +15 V, +5 V and -15 V power, an offset voltage supplied and controlled by the mainframe, and a clock/data signal pair for serial communication between the mainframe and "smart" probes.