The Tektronix Type 4S3 is a 1GHz dual-trace vertical sampling plug-in for the 661 oscilloscope. It uses two P6038 sampling probes. The probes contain sampling gates but not amplifiers. The front-end amplifier is therefore in the 4S3, and is composed of a 7308 tube (premium 6DJ8) with its two triodes connected in a common-cathode cascode topology.
- Tek 4s1 63cat.jpg
In 1963 Catalog