Amprobe AF-600 [4994405] A-Frame Cable Ground Fault Locator. The Amprobe AF-600 A-Frame Cable Ground Fault Locator is an optional accessory specifically designed for the Amprobe UAT-600 series. In combination with the Transmitter, it will pinpoint the place where a cable metal conductor (either a sheath or a metallic conductor of the wire) touches the ground. It can also detect other conductors to ground faults such as pipeline coating defects.