The Attenuator,variable, cataloged under National Stock Number 5985-00-520-3974, is classified within Federal Supply Class 5985 (Antennas, Waveguides, and Related Equipment) of the Electrical and Electronic Equipment Components group. The manufacturer of record is Telonic Berkeley, Inc. Dba Telonic Berkeley. Government technical data includes 25 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. 1 item shares a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5985-00-520-3974 |
| Primary Part Number | 8121S |
| Item Name | Attenuator,variable |
| FSC / FSG | 5985 / 59 — Antennas, Waveguides, and Related Equipment |
| Manufacturer | Telonic Berkeley, Inc. Dba Telonic Berkeley |
| Status | ACTIVE |
| Shaft Type | ROUND |
| Insertion Loss at Minimum Attenuation in Maximum Decibels | 0.2 |
| Impedance Rating in Ohms | 50.0 INPUT-OUTPUT |
| Mounting Facility Type and Quantity | 4 THREADED HOLE(S) |
| FSC Application Data | ANTENNAS,WAVEGUIDES,AND RELATED EQUIPMENT |
| Frequency Range | 0.000 HERTZ MINIMUM AND 2.000 GIGAHERTZ MAXIMUM |
| Shaft Diameter | 0.250 INCHES NOMINAL IN |
| Body Style | COAXIAL TYPE |
| Adjustment Device Type and Quantity | 1 KNOB AND 1 SHAFT |
| Overall Attenuation Range in Decibels | +0.0 TO 60.0 |
| Voltage Standing Wave Ratio | 1.30 |
| Mounting Facility Screw Thread Series Designator | UNIFIED NATIONAL COARSE (UNC) |
| Overall Attenuation Accuracy in Decibels | -1.80 TO 1.80 |
| Attenuation Per Step in Decibels | 10.0 |
| Attenuation Variation Method | STEPPED |
| Mounting Thread Quantity | 32 PER INCH |
| Shaft Length | 0.930 INCHES NOMINAL IN |
| Body Material | ALUMINUM ALLOY |
| Mounting Facility Nominal Screw Thread Diameter | 0.138 INCHES IN |
| Operating Temp Range | -55.0 TO 85.0 CELSIUS DEGC |
| Application Design | TRANSMISSION LINE |
| Terminal Type and Quantity | 2 CONNECTOR, COAXIAL, MALE |
| Power Rating | 3.0 WATTS AVERAGE AND 200.0 WATTS PEAK |
| Step Position Quantity | 10 |
| Coaxial Connector Series Designation | SMA |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | Possible hazard — SDS may be required (DLA HMIC P) |
| Criticality Code | X |
NSN 5985-00-520-3974 is a Attenuator,variable, manufactured by Telonic Berkeley, Inc. Dba Telonic Berkeley, classified under FSC 5985, Antennas, Waveguides, and Related Equipment. Status: active.
NSN 5985-00-520-3974 has 2 manufacturer part numbers on file: 228076-4 (Raytheon Company), 8121S (Telonic Berkeley, Inc. Dba Telonic Berkeley).
1 possible match (shared part number, not a government interchangeability claim): 2910-01-033-7864. Verify interchangeability with system specifications before substitution.
Key specifications for 8121S: Shaft Type: ROUND; Insertion Loss at Minimum Attenuation in Maximum Decibels: 0.2; Impedance Rating in Ohms: 50.0 INPUT-OUTPUT; Mounting Facility Type and Quantity: 4 THREADED HOLE(S). 25 specifications are documented in the U.S. Government catalog.
Possible hazard — SDS may be required (DLA HMIC P). 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.