As more and more communications equipment designs have adopted digital signal processing techniques, Rockwell Collins has announced that it will stop manufacturing its renowned mechanical filters. It did not provide a specific date.

“Over the past several years, we have seen a dramatic reduction in demand for narrowband analog filters,” the company said on its website. “Due to this and other economic reasons, [Rockwell Collins] Filter Products will be discontinuing its mechanical filter products in the near future.”

Rockwell Collins makes two different types of mechanical filters, many of which have found their way into Amateur Radio products and applications. In a mechanical filter, input and output transducers convert the electrical signal to and from resonant mechanical vibrations, respectively.

“For frequencies between 100 kHz and 700 kHz, we create filters made from rods resonating in a torsion mode,” the company explained on its website. “For frequencies below 100 kHz, we use flexure mode bar resonators.”

Collins has made mechanical filters for more than 6 decades, and their initial application was in telephone circuits. The filters gained favor for Amateur Radio use because of their excellent selectivity, especially in IF applications. It is said to take about 12 weeks to manufacture a single unit.

Art Collins, W0CXX (SK), founded Collins Radio Company in 1933 in Cedar Rapids, Iowa. That same year Collins supplied the equipment to establish communication with the Byrd South Pole expedition. Over the years, Collins produced a line of Amateur Radio equipment, and its products remain popular among radio amateurs and collectors. Rockwell International purchased the company in 1973, and Rockwell Collins was spun off in 2001. Today, the company has focused its market on electronic communications, avionics, and in-flight entertainment systems. — Thanks to Mike Morris, WA6ILQ; Rockwell Collins