AC128 Germanium transistor. DSI, TO-1 case

Description

1. Germanium Transistor: Like the AC127, the AC128 is made of germanium, a material that was commonly used in early transistors before silicon became more prevalent.

2. Low Power and Low-Frequency Applications: Germanium transistors are best suited for low-power, low-frequency applications. They are not suitable for high-frequency or high-power applications due to their limited frequency response and power handling capabilities.

3. TO-1 Metal Can Package: The TO-1 package is a metal can package with three leads (collector, base, and emitter). This package type provides physical protection to the fragile germanium material and allows for easy mounting on a circuit board.

4. Sensitivity to Heat: Germanium transistors are more sensitive to temperature variations than silicon transistors. They exhibit a negative temperature coefficient, meaning their performance can degrade with increasing temperature. Proper heat dissipation and temperature management are essential when using germanium transistors like the AC128.

5. Vintage and Collector’s Item: The AC128, being a vintage component, is sought after by electronics enthusiasts, vintage radio restorers, and collectors interested in vintage electronics. It is valuable for historical and collector’s purposes.