Tennelec

Tennelec was a US electronics company and known particularly for introducing the first programmable radio scanner, the Tennelec MCP-1.

Prior to the MCP-1, scanners were "manually programmed" by inserting a series of hand-cut crystals tuned for different frequencies. The scanner would then switch between the frequencies, stopping when the user pressed a switch. Tennelec got their start with a series of machines of this sort.

With the MCP-1 the user selected the frequencies they wanted to monitor by setting them up using binary coded decimal entered via sixteen switches on the front panel. Once selected, the system worked similarly to the older models, cycling through them until stopped. The advantage was that the system could be set up to monitor different sets of frequencies, police one night, fire departments the next.

The scanner was released at the Winter 1976 Consumer Electronics Show in Chicago. The system was a hit, and was soon picked up for Radio Shack. To help users get started, Radio Shack also purchased thousands of copies of Police Call, a guide to various radio frequencies. Two similar models followed, the MS-1 and MS-2.

Oddly, Tennelec went bankrupt soon after introducing their latest models. By this point other manufacturers, in particular SBE and Regency and Electra, had already introduced their own models.