The transistorized A5 channel bank for broadband systems

This article presents a brief historical background to the A-series of terminal units, used extensively in long-haul and short-haul transmission facilities to provide the first step of modulation from voice to carrier and the final step of demodulation from carrier to voice. Most of the paper is devoted to a description of the latest unit of this series — the A5 channel bank, which through the use of transistors and other modern components achieves significant improvements in size, power requirements and operating characteristics.