The Synchro,control Transformer, cataloged under National Stock Number 5990-00-121-2134, is classified within Federal Supply Class 5990 (Synchros and Resolvers) of the Electrical and Electronic Equipment Components group. The manufacturer of record is American Precision Industries, Inc Div Portescap Us. Government technical data includes 29 specifications, cited from the U.S. Government catalog. The record lists 2 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5990-00-121-2134 |
| Primary Part Number | SB673-21 |
| Item Name | Synchro,control Transformer |
| FSC / FSG | 5990 / 59 — Synchros and Resolvers |
| Manufacturer | American Precision Industries, Inc Div Portescap Us |
| Status | ACTIVE |
| Body Size | 8 |
| Shaft Type | ROUND, SLOTTED SINGLE SHAFT |
| Flange Diameter | 0.7500 INCHES NOMINAL IN |
| Undercut Width | 0.0620 INCHES NOMINAL IN |
| Shaft Diameter | 0.0900 INCHES NOMINAL SINGLE SHAFT IN |
| Rotor DC Resistance in Ohms | 225.00 NOMINAL |
| Undercut Diameter | 0.6910 INCHES NOMINAL IN |
| Fragility Factor | MODERATELY RUGGED |
| Body Style | STANDARD ROUND A |
| Flange Thickness | 0.0620 INCHES NOMINAL IN |
| Stator Input Current Rating | 81.0 MILLIAMPERES NOMINAL |
| Phase Shift Angle in Deg | 4.000 INPUT TO OUTPUT NOMINAL |
| Mounting Surface to Terminal End Distance | 1.2410 INCHES MAXIMUM IN |
| Frequency in Hertz | 400.0 NOMINAL |
| Zro Resistance in Ohms | 250.00 NOMINAL |
| Stator Input Electrical Power Rating | 200.0 MILLIWATTS NOMINAL |
| Plus J Zso Reactance in Ohms | 140.00 NOMINAL |
| Zrs Resistance in Ohms | 325.00 NOMINAL |
| Terminal Location | REAR |
| Shaft Maximum Radial Play | 0.0006 INCHES IN |
| Shaft Length | 0.3750 INCHES NOMINAL SINGLE SHAFT IN |
| Pilot Diameter | 0.5000 INCHES NOMINAL IN |
| Maximum Fundamental Null Voltage in Millivolts Per Volt | 30.00 INPUT |
| Stator Input Voltage Rating in Volts | 26.0 NOMINAL |
| Maximum Total Null Voltage Output in Millivolts Per Volt | 70.00 |
| Shaft Slot Width | 0.0200 INCHES NOMINAL SINGLE SHAFT IN |
| Plus J Zro Reactance in Ohms | 625.00 NOMINAL |
| Transformation Ratio | 0.465 ROTOR TO STATOR NOMINAL |
| Pilot Length | 0.0430 INCHES NOMINAL IN |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Part Number | Manufacturer |
|---|---|
| 8CT-101-A-5 | American Precision Industries, Inc Div Portescap Us (USA) |
| SB673-21 PRIMARY | American Precision Industries, Inc Div Portescap Us (USA) |
NSN 5990-00-121-2134 is a Synchro,control Transformer, manufactured by American Precision Industries, Inc Div Portescap Us, classified under FSC 5990, Synchros and Resolvers. Status: active.
NSN 5990-00-121-2134 has 2 manufacturer part numbers on file: 8CT-101-A-5 (American Precision Industries, Inc Div Portescap Us), SB673-21 (American Precision Industries, Inc Div Portescap Us).
Key specifications for SB673-21: Body Size: 8; Shaft Type: ROUND, SLOTTED SINGLE SHAFT; Flange Diameter: 0.7500 INCHES NOMINAL IN; Undercut Width: 0.0620 INCHES NOMINAL IN. 29 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.