The Tachometer Subassembly, cataloged under National Stock Number 6680-01-699-6740, is classified within Federal Supply Class 6680 (Liquid and Gas Flow, Liquid Level, and Mechanical Motion Measuring Instruments) of the Instruments and Laboratory Equipment group. The manufacturer of record is Uma Inc. Government technical data includes 3 specifications, cited from the U.S. Government catalog. The record lists 3 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 6680-01-699-6740 |
| Primary Part Number | 1A3-4 |
| Item Name | Tachometer Subassembly |
| FSC / FSG | 6680 / 66 — Liquid and Gas Flow, Liquid Level, and Mechanical Motion Measuring Instruments |
| Manufacturer | Uma Inc |
| Status | ACTIVE |
| Overall Diameter | 35.052 MILLIMETERS NOMINAL MM |
| Accessory Components and Quantity | INCLUDED IS A 0.156 IN DIAM TANG WITH A 6 FT HARNESS IN |
| Special Markings | NAME PLATE WITH UMA NO, SERIAL NO, AND WEIGHT IN LBS |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
NSN 6680-01-699-6740 is a Tachometer Subassembly, manufactured by Uma Inc, classified under FSC 6680, Liquid and Gas Flow, Liquid Level, and Mechanical Motion Measuring Instruments. Status: active.
NSN 6680-01-699-6740 has 3 manufacturer part numbers on file: 10-01706 (Irwin International, Inc. Dba Irwin International Inc), 1A3-4 (Uma Inc), 10-01706 (Scandinavian Avionics A/s).
Key specifications for 1A3-4: Overall Diameter: 35.052 MILLIMETERS NOMINAL MM; Overall Length: 81.28 MILLIMETERS NOMINAL MM; Accessory Components and Quantity: INCLUDED IS A 0.156 IN DIAM TANG WITH A 6 FT HARNESS IN; Special Features: 1A3 TSU IS DESIGNED TO WORK WITH UMA TSU TACHOMETERS ONLY. SCREW INTO THE ENGINE'S MECHANCIAL TACHOMETER PORT. 4 PIN MALE CONNECTOR (UMA 11216): PIN 1 POWER INPUT (+VSS), PIN 2 GROUND, PIN 3 SIGNAL OUTPUT, PIN 4 NOT USED.. 3 specifications are documented in the U.S. Government catalog.
No hazard code in the DLA record (HMIC N). Hazard information on this page is shown exactly as it appears in the DLA record.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-16.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-18.