The BT-300 WT line locator enables the tracing and testing of individual wires, of pairs of wires, communication lines as well as data and network lines. The BT-300 WT consists of a transmitter and receiver. The transmitter couples a reference signal to the line being traced and this signal can be detected by the receiver to identify the cable. Likewise, RJ45 (network) and RJ11 (telephone) cables can be checked for correct cabling.