The Time Standard, cataloged under National Stock Number 6645-01-134-2976, is classified within Federal Supply Class 6645 (Time Measuring Instruments) of the Instruments and Laboratory Equipment group. The manufacturer of record is Efratom Time & Frequency Products, Inc Dba Datum - Irvine Div Datum - Irvine. Government technical data includes 2 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through both NSN and commercial part number lookups. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 6645-01-134-2976 |
| Primary Part Number | 670502-6 |
| Item Name | Time Standard |
| FSC / FSG | 6645 / 66 — Time Measuring Instruments |
| Manufacturer | Efratom Time & Frequency Products, Inc Dba Datum - Irvine Div Datum - Irvine |
| Status | ACTIVE |
| General Characteristics Item Description | RUBIDIUM FREQUENCY STANDARD; OUTPUT: 10 MHZ SINE WAVE,0.5 VRMS; 50 OHMS IMPEDANCE; INPUT POWER: 22.5 TO 32.0 VDC; 18.0 WATTS MAX AT 25 DEG C AMBIENT AND 26 VDC; STORE AT UP TO 95 PCT RELATIVE HUMIDITY; HARDENED TO GROUND TACTICAL ENVIRONMENT; INTERNAL DIODE PROTECTS AGAINST REVERSED POLARITY; SHOCK (NON-OP) PER MIL-STD-202E,METHOD 213B,TEST CONDITION-J; VIBRATION (NON-OP) PER MIL-STD-202E,METHOD 204C,TEST CONDITION-A MHz |
| Storage Temp Range | -60.0 TO 71.0 CELSIUS DEGC |
| 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 |
|---|---|
| FE-5602B | Frequency Electronics Inc (USA) |
| 670502-6 PRIMARY | Efratom Time & Frequency Products, Inc Dba Datum - Irvine Div Datum - Irvine (USA) |
| Reference | Meaning |
|---|---|
| 626404-2 | 7/2 Vendor item drawing reference Raytheon Company |
| 270502-6 | 5/9 Secondary reference Efratom Time & Frequency Products, Inc Dba Datum - Irvine Div Datum - Irvine |
| M-100 | 5/9 Secondary reference Efratom Time & Frequency Products, Inc Dba Datum - Irvine Div Datum - Irvine |
NSN 6645-01-134-2976 is a Time Standard, manufactured by Efratom Time & Frequency Products, Inc Dba Datum - Irvine Div Datum - Irvine, classified under FSC 6645, Time Measuring Instruments. Status: active.
NSN 6645-01-134-2976 has 2 manufacturer part numbers on file: FE-5602B (Frequency Electronics Inc), 670502-6 (Efratom Time & Frequency Products, Inc Dba Datum - Irvine Div Datum - Irvine).
Key specifications for 670502-6: General Characteristics Item Description: RUBIDIUM FREQUENCY STANDARD; OUTPUT: 10 MHZ SINE WAVE,0.5 VRMS; 50 OHMS IMPEDANCE; INPUT POWER: 22.5 TO 32.0 VDC; 18.0 WATTS MAX AT 25 DEG C AMBIENT AND 26 VDC; STORE AT UP TO 95 PCT RELATIVE HUMIDITY; HARDENED TO GROUND TACTICAL ENVIRONMENT; INTERNAL DIODE PROTECTS AGAINST REVERSED POLARITY; SHOCK (NON-OP) PER MIL-STD-202E,METHOD 213B,TEST CONDITION-J; VIBRATION (NON-OP) PER MIL-STD-202E,METHOD 204C,TEST CONDITION-A MHz; Storage Temp Range: -60.0 TO 71.0 CELSIUS DEGC. 2 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.