Manufacturers:
- Saba
- Sage Instruments
- Sailor
- Samar
- Samlex America Inc.
- Samsung
- Sangean
- Sansui
- Sanwa
- Sanyo
- Satorius
- SBE Sideband Engineers Inc.
- Schaevitz MCD
- Schaffner
- Schaub-Lorenz
- Schlumberger
- Schomandl
- Scopex Instruments Ltd
- Seco Manufacturing Company
- Sefram
- Seiko I Infotech Inc.
- Semcor
- Sencore
- Sennheiser Electronic
- Sequential Circuits
- SGC Inc.
- Sharp
- Sherwood
- Shishi Feitong Communication Equipment
- Shure
- Siel
- Siemens
- Sigma Corporation
- Silver Marshall Inc.
- Simpson
- Sinclair
- Singer
- Singer Instrumentation
- Sinudyne
- Skanti
- Skuttle
- Slade Radio PTY LTD
- Slaughter Company
- Smiths Radiomobile
- SOCIETE FRANÇAISE RADIO - ÉLECTRIQUE
- Solar Manufacturing Corporation
- Solartron
- Sommerkamp
- Sony
- Sony Ericsson
- Sorensen Company
- Sound Technology
- Soundtracs PLC
- SP Radiotechnika Wroclaw
- Spectracom
- Spectrian Corporation
- Spectro Acoustics
- Spectronics
- Spilsbury Communications Ltd.
- Spirent Communications Inc.
- Spraque Electric Company
- SRS Stanford Research Systems
- Stancor Standard Transformer Corporation
- Standard Communications
- Standard Radio & Telefon AB
- Star Instruments
- Statron
- Stearns Magnetics
- Stoelting
- Studer
- Subaru
- Sun Microsystems
- SunBrite
- Superior Instruments
- Supreme Instruments Corporation
- Swan Electronics Corp.
- Sylvania Electric Products
- Symetrix
- Systron Donner
