453

The Tektronix 453 is a portable 50MHz dual-trace oscilloscope from the mid-1960's to the mid-1970's. Initial versions had nuvistor tubes in the front end as cathode-follower voltage buffers. Later versions used FETs for the same purpose. The vertical amplifier that drives the CRT deflection plates is a cascoded differential amplifier made of NPN transistors. Triggering is by tunnel diode, with a trigger preamplifier preceding that actual trigger circuit. The 453 was almost entirely solid-state even in its first version. The only tubes other than the CRT are the 5642 HV rectifiers and a few 8393 nuvistor triode tubes.