Hersteller
- California Instruments
- Camco
- Candy
- Canon
- Cardiac Science
- Cardinal Health
- Cardioline
- Carl Zeiss
- Casio
- Castellini
- CBS Laboratories
- Central Electronics
- Century Electronics
- Chauvin Arnoux
- Chicago Transformer
- Chinaglia Dino Elettrocostruzioni
- Christian Schwaiger Gmbh
- Chrysler
- Citizen
- Clamann & Grahnert
- Clarion
- Clark Hess Communication Research Corp
- Clarostat Mfg. Co. Inc.
- Clatronic
- CM Clemens Manufacturing Company
- Codar Radio Company
- Cognitive Vision Inc
- Collins Telecommunications
- Combinova
- Commodore
- Communication Technology Group
- Compaq Computer Corporation
- Compliance Design Inc.
- Compliance West
- Conar Coletronics Service Inc.
- Cornell Dubilier Electronics
- Cosmed
- Cossor
- Coutant Electronics
- Cox
- CRC
- Creative
- Crest Audio
- Criticare Systems Inc.
- Critikon
- Crosby Laboratories
- Crown
- CRT
- Crumar
- CT Systems INC
- CTC Union Technologies
- CTR Elektronik
- CTX
- CU Medical Systems Inc.
- Cushcraft Corporation
- Cushman Electronics Inc.
