WA9UKW
AT&T/Western Electric Modem History
During my 23+ years at Western Electric (1966-1990), I worked directly with many of these modem systems, testing and maintaining them for various applications including medical systems, airline communications, and FAA control systems.
📡 The Early Days (1960s-Early 1970s)
Bell 103 Standard
- Frequency Shift Keying (FSK) modulation
- Full-duplex operation
- 300 bits per second speed
- Industry standard for early data communication
200 Series Modems
- Support for 1200 baud (1.2kb/sec)
- Acoustic coupling techniques
- Industrial-grade construction
- Typically rack-mounted for business use
🔄 Mid-1970s Evolution
Bell 212A Innovation
- Phase Shift Keying (PSK) modulation
- 1200 baud communication
- Industry standard for business communication
Technical Advances
- Introduction of integrated circuits
- Direct connection via modular jack
- Quadrature Phase Shift Keying (QPSK)
- Enhanced reliability and smaller size
💻 The 1980s Transition
Bell 208/209 Series
- 4800/9600 Baud speeds
- Multiple encoding levels
- Data compression methods
- Dedicated line options
Market Changes
- Shift from leased to purchased equipment
- Increased market competition
- Introduction of error correction
- MNP levels 1-4 implementation
🌟 Western Electric's Legacy
- Known for exceptional reliability and durability
- Set industry standards through Bell standards
- Focused on business and institutional customers
- Maintained high manufacturing quality
Many of these standards and technologies laid the groundwork for modern internet and networking protocols we still use today.