- The AT-30 Tachometer is a rugged instrument with solid-state circuitry for indication of engine RPM. This model will accept all signal sources: alternator, magnetic pickup or ignition, and has improved the calibration procedure to a single push button on the back. It is equipped with a ring nut for mounting into a standard 3-3/8 in. (86 mm) dash mounting hole. A full 240° sweep of the pointer gives an accurate indication on a large easy–to–read scale, and the dial can be illuminated.
The AT-30 tachometer is a rugged instrument with solid-state circuitry for indication of engine RPM. It is equipped with a ring nut for mounting into a standard 3-3/8 in. (86 mm) dash mounting hole. A full 240° sweep of the pointer gives an accurate indication on a large easy-to-read scale, and the dial can be illuminated for night reading. This AT Series tachometer indicates engine speed in revolutions per minute (RPM). Calibration has been improved and is now accomplished with a single push button on the back. Not intended for use with Capacitive Discharge (CD) ignitions or magnetos, only for inductive, automotive-type ignitions. The tachometer is for negative ground or isolated electrical systems. If the instrument is connected to reverse polarity, it will not operate until proper connections are made. It is powered by a 12- or 24-volt battery (operating range: 10-32 VDC). Replaces Murphy part numbers: ATS-30-12 (20700188), ATS-30-24 (20700202), ATS-40 (20700227), ATA-30-12 (20700175), ATA-30-24 (20700198), ATA-40 (20700134).