Radio frequency line tracers, audio frequency line tracers, pipe and cable locators, multi-frequency pipe and cable locators, power line detectors, fiber optic cable locating systems, namely, multi-channel RF transmitter, filter modules, surge protection modules, relay modules, splice boxes, namely, laser range finders, and handheld locate receivers; pipeline current mapping systems, namely, multi-channel RF transmitter, filter modules, relay modules, splice boxes, namely, laser range finders, and handheld locate receivers, ball marker locators comprising signal transmitters, signal receivers and indicators; valve box locators, iron and steel locators, hand-held electronic amplification leak detectors, digital resistance cable fault locators, hand-held inductive probes, electromagnetic transmitters, hand-held underwater locators, sheath fault locators, fiber optic intercoms, time domain reflectometers, copper cable telecom loop analyzers, and directional drilling guidance control equipment, namely, transmitters, receivers, and distance measurement devices