533

The Tektronix Type 533 is a 15 MHz oscilloscope introduced in 1958 that uses letter-series and 1-series plug-ins. It is similar to a 535, but without the second, delayed timebase. Instead, it has a range of horizontal magnifiers from X2 to X100. It has 10kV accelerating voltage. It uses 500 watts and weighs 62 pounds. The vertical amplifier consists of a 12BY7 differential amplifier followed by a 6DJ8 cathode-follower, followed by a 6197 differential (common-cathode) output stage that drives the 200ns L-C delay line, which drives the vertical deflection plates of the CRT. Trigger pickoff is taken after the cathode follower stage in the vertical amplifier. There is a 6DJ8 differential trigger pickoff amplifier followed by half of a 6DJ8 a cathode follower, buffering the trigger signal. The trigger circuit is a 6DJ8 trigger amplifier followed by a 6DJ8 Schmitt trigger. Triggering can be from the internal pickoff or from an external signal or "line" trigger, from a 6.3V tap on the power transformer. The 533 contains a 128F thermal cutoff. The high voltages for the CRT, +8650 and -1350 volts, are generated by a 60 kHz Hartley power oscillator and five 5642 high-voltage rectifier diode tubes.

• Tektronix 533 and 533A Manual (PDF)

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  front from different 533A