Manufacturers:
- Tait Electronics Limited
- Takeda Riken
- Tandberg
- Tapetone
- Taylor Electrical Instruments
- Teac
- techni-rite
- Technics
- TechniSat Digital GmbH
- TechnoTrend Aktiengesellschaft
- Tekk
- Tektronix
- Tele-Path Instruments
- Telecom Analysis Systems Inc.
- Telecommunications Techniques Corporation
- Telefunken
- Telequipment
- Telewave Inc.
- Telonic Industries
- Ten-Tec
- Tenma Test Instruments
- Tensai
- Tento
- Tesla
- Testboy
- Text Tell
- Thandar
- The Clough-Brengle Co.
- The Gramophone Company Ltd.
- the hallicrafters co.
- Thermo Electron Corporation
- Thermo Scientific
- Thomson
- Thurlby Thandar Instruments TTI
- Tigertronics
- Tiptel
- TMC Technical Materiel Corporation
- Toellner
- Tokyo Hy_Power Labs
- Top Band Systems
- Topwards Electronics Instruments
- Torrestronics Inc.
- Toshiba
- Toyota
- Tracor
- Transel Corporation
- Transmation Inc.
- Trexon
- Triadex Inc.
- Trilithic
- Trio Electronics
- Trion
- Triplet
