PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

CM-77A/USMConverter,frequency,electronic

Joint Electronics Type Designation System · NSN 5985-00-080-7204 · FSC 5985 · No Item Name Available
Verified by PartsTable
NSN 5985-00-080-7204 — this item is cataloged by the U.S. Government under National Stock Number 5985-00-080-7204. Primary manufacturer part number: CM-77A/USM.
Features
  • Converter,frequency,electronic — FSC 5985
  • Circuit Construction Type: ELECTRON TUBE
  • Operating AC Frequency in Hertz: 1000.0 MAXIMUM SINGLE VOLTAGE
  • Frequency Per Channel: 12.4 GIGAHERTZ MAXIMUM OPERATING CHANNEL
  • External AC Operating Voltage in Volts: 230.0 MAXIMUM SINGLE VOLTAGE
  • Average Life Measurement: NOT RATED
  • Basic Shape Style: RECTANGULAR OR SQUARE
  • Operating AC Frequency in Hertz: 50.0 MINIMUM SINGLE VOLTAGE
Applications
  • Industrial maintenance and repair
  • Government and military logistics
  • Equipment overhaul and refurbishment
General Description

The Converter,frequency,electronic, cataloged under National Stock Number 5985-00-080-7204, is classified within Federal Supply Class 5985 (No Item Name Available) of the Electrical and Electronic Equipment Components group. The primary manufacturer of record is Joint Electronics Type Designation System. Government technical data includes 18 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 5 commercial cross-references from 5 manufacturers, enabling identification through both NSN and commercial part number lookups. 2 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Cancelled.

Technical Specifications
ParameterValue
NSN5985-00-080-7204
Primary Part NumberCM-77A/USM
Item NameConverter,frequency,electronic
FSC / FSG5985 / 59 — No Item Name Available
ManufacturerJoint Electronics Type Designation System
StatusCANCELLED
Circuit Construction TypeELECTRON TUBE
Operating AC Frequency in Hertz1000.0 MAXIMUM SINGLE VOLTAGE
Frequency Per Channel12.4 GIGAHERTZ MAXIMUM OPERATING CHANNEL
External AC Operating Voltage in Volts230.0 MAXIMUM SINGLE VOLTAGE
Average Life MeasurementNOT RATED
Basic Shape StyleRECTANGULAR OR SQUARE
Operating AC Frequency in Hertz50.0 MINIMUM SINGLE VOLTAGE
External AC Operating Voltage in Volts115.0 MINIMUM SINGLE VOLTAGE
Reference Data and LiteratureDEPT OF ARMY PUBLICATIONS: TB9-6625-336-50,19 NOV 64; TM11-6625-493-15 W/ CHANGES 1 & 2,29 SEP 64; TM 11-6625-493-20P; TM11-6625-493-45P,19 OCT 64 W
Functional DescriptionEXTENDS FREQUENCY MEASUREMENT RANGE OF AN/USM-26 & AN/USM-207A INTO MICROWAVE RANGE; ALONG W/ AN/USM-26 OR -207A CAN MEASURE FREQUENCIES UP TO 12.4 GHZ,OR W/ AN EXTERNAL MIXER 1-18 GHZ; CAN BE USED W/OUT A FREQUENCY COUNTER TO MEASURE FREQUENCIES BELOW 4 GHZ W/IN ABOUT PORM 0.5 PCT; FREQUENCY IS DETERMINED BY ZERO-BEATING THE UNKNOWN SIGNAL W/ A HARMONIC OF AN EXTREMELY STABLE SIGNAL GENERATED W/IN & TO MEASURE CM-77A FUNDAMENTAL FREQUENCY ON A COUNTER; MULTIPLYING COUNTER READOUT BY HARMONIC CAUSING THE ZERO-BEAT GIVES INPUT FREQUENCY; HARMONIC NO. IS DETERMINED FROM PREVIOUS KNOWLEDGE OF INPUT FREQUENCY OR BY COMPUTATION; ZER/-BEAT IS DISPLAYED ON INTERNAL OSCILLOSCOPE GHz
Frequency Per Channel10.0 MEGAHERTZ MINIMUM OPERATING CHANNEL
Installation DesignTOP OF CABINET/COUNTER
Inclosure TypeENCASED
Entry Date70-12-01
Relationship to Similar EquipmentINTERCHANGEABLE W/ 6625009739267 & 6625007355167; SIMILAR TO CM-77/USM
Type/model DesignationCM-77A/USM A
Functional ClassificationAA-6.3
PhaseSINGLE
Lifecycle & Compliance
Acquisition StatusCANCELLED
HAZMATNo
Verified Substitutes 2
6625-00-288-0184540B INTERCHANGEABLE
Calibrator,voltage
Fluke Corp
4940-01-058-7328 INTERCHANGEABLE
Leak Detector,refrigerant Gas
Cross-Reference Index
Part NumberManufacturer
CM-77A/USM Joint Electronics Type Designation System (USA)
540B Hewlett-Packard Company Dba HP (USA)
540B Keysight Technologies, Inc. (USA)
CM77AUSM Boustead Electric and Mfg Co (USA)
540B Keysight Technologies Inc (USA)
Related Parts
6625-00-288-0184INTERCHANGEABLE
CALIBRATOR,VOLTAGE
540B
4940-01-058-7328INTERCHANGEABLE
LEAK DETECTOR,REFRIGERANT GAS

Frequently Asked Questions

What is NSN 5985-00-080-7204?

NSN 5985-00-080-7204 is a Converter,frequency,electronic, manufactured by Joint Electronics Type Designation System, classified under FSC 5985 (No Item Name Available). Status: cancelled.

What are the part numbers for NSN 5985-00-080-7204?

NSN 5985-00-080-7204 has 5 cross-referenced part numbers: CM-77A/USM (Joint Electronics Type Designation System), 540B (Hewlett-Packard Company Dba HP), 540B (Keysight Technologies, Inc.), CM77AUSM (Boustead Electric and Mfg Co), 540B (Keysight Technologies Inc).

What NSN replaces 5985-00-080-7204?

There are 2 known substitutes for 5985-00-080-7204: 6625-00-288-0184, 4940-01-058-7328. Verify interchangeability with system specifications before substitution.

What are the specifications of CM-77A/USM?

Key specifications for CM-77A/USM: Circuit Construction Type: ELECTRON TUBE; Operating AC Frequency in Hertz: 1000.0 MAXIMUM SINGLE VOLTAGE; Frequency Per Channel: 12.4 GIGAHERTZ MAXIMUM OPERATING CHANNEL; External AC Operating Voltage in Volts: 230.0 MAXIMUM SINGLE VOLTAGE. 21 total characteristics are documented in the Federal Logistics Information System.

Is NSN 5985-00-080-7204 still in active supply?

NSN 5985-00-080-7204 is currently cancelled. Check with the Defense Logistics Agency for current availability and authorized substitutes.

Validated with multiple authoritative sources, including Government, OEM, and Certified sources.
PartsTable Design LLC · partstable.com