Tennelec

Lore & Background

Tennelec was founded in the early 1960s by Edward Fairstein in Oak Ridge, Tennessee. The company initially focused on nuclear instrumentation, and the TC-200 amplifier became a successful early design that established Tennelec as a leader in that field. Following this success, the company developed additional components for precise nuclear measurement, including detectors and particle counters.

In the 1970s, Tennelec's Commercial Products Division produced innovative scanning radios. The first programmable radio scanner was the Memoryscan, introduced in 1974 and later known as the Memoryscan 1 (model MS-1). A slightly improved model, the Memoryscan 2 (model MS-2), followed. Prior to these, scanners were programmed by inserting hand-cut crystals for different frequencies. The MS-1 and MS-2 allowed users to select up to 16 frequencies using binary codes entered via two pushbuttons, with 16 toggle switches to choose which frequencies to monitor. The first scanner allowing direct entry of decimal frequencies on a keypad was the Tennelec MCP-1, released at the Winter 1976 Consumer Electronics Show in Chicago. It was soon picked up for Radio Shack, which also purchased thousands of copies of Police Call to help users get started.

Partly due to poor quality control of their scanner line, Tennelec filed for bankruptcy soon after introducing their latest radio models. By that point, other manufacturers such as SBE, Regency, and Electra had already introduced their own programmable models. Tennelec, still located in Oak Ridge, Tennessee, is now a division of Mirion Technologies, which acquired Tennelec's previous parent company, Canberra Industries.

Reader's Guide

Tennelec's significance lies in its dual contributions to nuclear instrumentation and consumer radio scanning. In the nuclear field, the TC-200 amplifier established the company as a leader, enabling precise measurement in research and industry. In radio scanning, Tennelec pioneered programmable technology with the Memoryscan series, which replaced the cumbersome crystal-based tuning with binary-coded frequency selection. This innovation allowed users to easily switch between sets of frequencies, such as police or fire departments. The MCP-1 further advanced the field by introducing direct decimal frequency entry via a keypad, a feature that became standard. Its adoption by Radio Shack brought programmable scanning to a wider audience. However, poor quality control in later models led to Tennelec's bankruptcy, allowing competitors like SBE, Regency, and Electra to dominate the market. The company's legacy endures through its early innovations and its continued existence as a division of Mirion Technologies, still based in Oak Ridge.

Did You Know?

• Tennelec was founded by Edward Fairstein in Oak Ridge, Tennessee, in the early 1960s.
• The first programmable radio scanner was the Tennelec Memoryscan, introduced in 1974.
• The Tennelec MCP-1 was the first scanner to allow direct entry of decimal frequencies on a keypad.
• Tennelec filed for bankruptcy partly due to poor quality control of its scanner line.