570

The Tektronix 570 is a curve tracer for tubes. It was introduced in 1955. It sweeps the plate voltage between zero and a selectable maximum voltage while "stepping" the control grid through a set of voltages.

A selectable screen voltage is available for testing tubes with screens. The plate voltage is measured and applied to the X-axis of the display. The plate current is measured and amplified and is applied to the Y-axis of the display.

The 570 contains five transformers:

• T310: center-tapped isolation transformer for plate sweep
• T340: multitap transformer for heater voltages
• T401: multitap autotransformer for selecting peak plate voltage, feeds T310
• T501: transformer for floating supplies and screen voltage supply
• T620: transformer for 60kHz HV power oscillator for CRT voltages

The screen supply is regulated and uses a 6CD6GA tube as the series regulator.

The vertical and horizontal amplifiers are almost identical. The first stage is a differential amplifier made of two 6AU6 tubes. The second stage is a differential amplifier made of both halves of a 6BQ7A.

• Tektronix 570 Manual 070-167 (good quality, OCR, PDF)
• Tektronix 570 Manual (good quality, PDF)
• Tektronix 570 Manual (mediocre quality, PDF)
• Tektronix 570 Factory Calibration Procedure (PDF)

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