The Kineplex System

One central theme over the decades was the use of increasingly higher frequencies in the electromagnetic spectrum, from the relatively long waves of radio frequencies through microwave energy and into the use of visible light. This trend was driven by the simple principle that the higher the frequency (and smaller the wavelength) the more information that can be encoded and transmitted in a given length of time. With increased use of this energy spectrum for all types of communication, potential users soon were in competition for a portion of the spectrum free from interference by other users. Laws and regulations were necessary to assign specific frequencies to specific users (AM and FM commercial broadcast, military, aviation, etc.). “Bandwidth” became a scarce and valuable resource. New technology was needed that could compress encoded information into smaller and smaller bandwidth.

Collins Radio answered this challenge in the 1950s by inventing the Kineplex system, which used a binary (on/off or +/-) code, generated by pulses of an audio tone which modulated a radio frequency carrier. Voice (teletype) and data were separated into 40 channels on the basis of their phase relationships (within a 360 degree sinewave); the system was capable of sending and receiving 3000 bits / sec or 100 teletype words per minute. The pulse code modulation technique, with precise pulse timing and frequency stability, produced virtually error-free communication. The 40 channels were compressed into the bandwidth of one of the then-current telephone voice channels, a remarkable achievement at the time. The heart of Kineplex was the world’s first MODEM (modulator/demodulator), first tested in the early 1950s and mass-produced in a transistorized version in 1956. Much of the Kineplex system used standardized modules, similar to the rack-mounted “black boxes” used in avionics equipment. This architecture was employed in many Collins Radio product lines, including the C-System computers of the 1960s and 1970s. Modular design has many advantages in design, manufacture, and maintenance.

Kineplex signaled a new direction for Collins Radio Company, providing data processing and data transmission for industry among remotes sites using a variety of media: telephone lines, coax cable, radio, or microwave links. This early vision of a data network was promoted in a remarkably prescient article in the 1957 Collins Signal: “With the implementation of data processing centers using high speed electronic computers - - - a new area is opening up for data transmission. Kineplex equipment with its high density, high speed capability will fit nicely into this picture for linking plants and offices.”