The SN76 tachometer signal adapter will amplify a weak tachometer signal and double the frequency. This is useful for converting four-cylinder computer tachometer signals (computer signals tend to be four-cylinder, even if the engine is an eight-cylinder) to work with eight-cylinder tachometers.

Classic Instruments’ 3-3/8-inch tachometers work with four-, six-, or eight-cylinder signals and some 12-pole alternator signals; 4-5/8-inch tachometers work with four-, six-, or eight-cylinder signals and some 10-, 12-, and 20-pole alternator signals.

Classic Instruments tachometer combo gauges with push-button calibration function are compatible with signals of 1 to 14 cylinders and are also compatible with weaker 5V computer tachometer signals.

SOURCE
Classic Instruments
1299 M-75 South
P.O. Box 411
Boyne City
MI  49712
800-575-0461
www.classicinstruments.com