575

The Tektronix 575 is a curve tracer for transistors, introduced in March 1957. It can be thought of as being composed of three modules:

1. An X-Y display. The vertical and horizontal amplifiers are very similar, using the two halves of a 6CG7 dual-triode tube as the output amplifier. The CRT has -1700V on the cathode and +2500V on the anode. The HV power supply uses two 5642 rectifier tubes.
2. A step source. This uses a gated miller integrator to generate controlled steps. The result is a staircase waveform, which generates different traces in the the family of I-V curves of the transistor.
3. The collector sweep. Power from the mains goes through an isolation transformer and a variac and is rectified by germanium diodes to produce the collector sweep voltage. The isolation transformer has two pairs of secondary taps, one for high voltage (0 to 200V) and low current, the other for low voltage (0 to 20V) and high current. The maximum power that can be delivered to the transistor in either mode is approximately 200 watts.

The 575 can be paired with a 175 for high current device measurements.

It is possible to use the 575 as an X-Y monitor. The vertical and horizontal range switches have settings for external input, at 0.1 V/div sensitivity.

Early 575 versions used selenium rectifiers. A kit for conversion to silicon diodes was available and is documented in the back of the manual. The 575 has a thermal cutoff.

• Tektronix 575 and 175 Manual (PDF)
• Tektronix 575 with Mod 122C Manual (PDF)
• "A Power Curve Tracer At Surplus Prices" by Dennis L. Feucht (PDF)
• Some Transistor Measurements Using the Type 575
• Tektronix 575 Factory Calibration Procedure (PDF)

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  575 w/o Mod 122C

• 575 w Mod 122C

  575 w Mod 122C

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  unmodified collector supply

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  collector supply rectifier with MOD122C