The Tektronix 455 is a 50 MHz dual-trace solid-state portable oscilloscope. It is functionally similar to the 453 and can be seen the successor of the 453. The 455 makes extensive use of integrated circuits and is smaller and lighter than the 453.
The final stage of the 455 vertical amplifier employs a differential pair of triple-stacked NPN transistors. The purpose of the stacking is to get higher voltage swing and to eliminate the need for a heat sink.
The 455 uses a linear power supply.
Triggering is done with 155-0121-00 chips, one per channel.