575

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The Tektronix 575 is a curve tracer for transistors, introduced in March 1957.

It can be thought of as being composed of three modules: an X-Y display, a step source, and a collector sweep source.

Unlike later curve tracers, the 575 can optionally display base voltage on the vertical axis.

Key Specifications

Collector Sweep 0−200 V minimum peak with 1 A current curves, 0−20 V minimum peak with 20 A current curves
Vertical Display IC 0.01 mA/div to 1 A/div ±3% in 16 Steps, or UB 0.01 V/div to 0.5 V/div ±3% in 6 Steps
Horizontal Display UC 0.01 V/div to 20 V/div ±3% in 11 Steps, or UB 0.01 V/div to 0.5 V/div ±3% in 6 Steps
CRT T0520, P1 phosphor, P2/P7/P11 on request; 4.2 kV acceleration
Power 105−125 V or 210−250 VAC, 50 to 60 Hz; 200 W in standby, 400 W max; thermal cutoff
Size (W/L/H) 13" × 24" × 16¾"
Weight ~30 kg (70 lb)

Links

Documents Referencing 575

Document Class Title Authors Year Links
Service Scope 50 Jun 1968.pdf Article Measuring FETs with a Type 575 1968
Tekscope 1969 V1 N5 Oct 1969.pdf Article Troubleshooting the Sweep Ciruits Charles Phillips 1969
Tekscope 1975 V7 N3.pdf Article A Potpourri of Modifications and Service Hints 1975

Documents Referencing Curve tracers

Document Class Title Authors Year Links
062-1009-00.pdf Book Measurement Concepts: Semiconductor Device Measurements John Mulvey 1969
Tekscope 1969 V1 N1 Feb 1969.pdf Article Curve Tracing Displays 1969
Tekscope 1969 V1 N5 Oct 1969.pdf Article Troubleshooting the Sweep Ciruits Charles Phillips 1969
Tekscope 1972 V4 N3 May 1972.pdf Article Semiautomatic Testing with the Curve Tracer Jack Millay 1972
Tektronix Curve Tracers - Device Testing Techniques.pdf Book Tektronix Curve Tracers - Device Testing Techniques 1985

History

John Kobbe says:

When transistors started to become practical, Tek sent Bill Polits to Michigan, for a 2 week primer on transistors. He in turn communicated it to the rest of us who were interested. That called for a transistor curve tracer. It used a similar step generator as the tube curve tracer but otherwise needed mostly new circuits. I remember a day at the beach, I was trying to hide from the sun while everyone else was getting their sunburn. I dug the sand out from under our new 1954 Chevy, got comfortable and figured out the circuits for the curve tracer soon to become the 575. Deane Kidd did the hard part when he designed the switches.

Internals

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 −1700 V on the cathode and +2500 V on the anode. The HV power supply uses two 5642 rectifier tubes.

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.

Step Source

This uses a gated Miller integrator to generate controlled steps. The result is a staircase waveform, which generates different traces in the family of I-V curves of the transistor.

Power Supplies

The 575 contains three separate power supplies:

  • A main power supply around T601 (120-095 and, later, 120-0095-01), supplying power to the amplifiers and step generator in the 575.
This power supply follows the standard 500-series power supply design.
In addition to heater power, it provides −150 V, +100 V, +300 V regulated and +400 V unregulated output.
It uses a mix of tubes and silicon or selenium rectifiers (earlier S/N) for rectification.
The −150 V and +400 V unregulated/+300 V regulated rails are supplied through 6BW4 full wave rectifier tubes, the +100 V circuits through silicon diodes/selenium rectifiers.
The −150 V rail is the main reference supply. Its regulator uses a 5651 voltage reference, a 6AN8 as the comparator/error amplifier, and a 12B4 as series pass tube.
The +100 V regulator uses a 6080 series pass tube and a 6AU6 tube as the error amplifier.
The +300 V regulator is similar to the +100 V circuit, except that it uses a 12B4 series pass tube.
Unregulated +400 V is provided for the CRT HV Oscillator.
  • A high-voltage supply around T801, supplying the CRT voltages, +2300 V for the CRT anode and −1700 V for the CRT cathode.
This HV power supply uses a 6AQ5 as the HV oscillator tube, and a 12AU7 as the feedback/error amplifier.
  • A collector sweep supply for the device under test.
Power from the mains goes through an isolation transformer (T701) and a variac (T702) 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 200 V) and low current, the other for low voltage (0 to 20 V) and high current.
The maximum power that can be delivered to the transistor in either mode is approximately 200 Watts.
575s with Mod 122C offer extended collector sweep voltage to 400 V.

Rectifiers

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

Type 175 High Current Adaptor

575 on top of a 175

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

See Also

Pictures

Internal

Schematics

Components

Some Parts Used in the 575

Part Part Number(s) Class Description Used in
120-0095-01 120-0095-01 Discrete component power transformer 575
120-226 120-226 Discrete component 117 V/1700 V power transformer 575 560-Series Diode Curve Tracer
12AU6 154-0040-00 Vacuum Tube (Pentode) RF pentode 81 112 1L10 1L20 1L60 3L10 512 556 575 545 547 549 581 585 A B C G K H L ML M N O R S Z
12AU7 154-041 154-0041-00 154-0287-00 Vacuum Tube (Dual Triode) dual medium-μ triode 104 104A 122 160 161 162 181 190 310 310A 316 317 3C66 502 502A 507 511A 512 516 517 517A 524 526 535 536 545 545A 545B 547 549 555 561 564 570 575 581 581A 585 585A C D E N Q Hickok 1825
5642 154-0051-00 154-0079-00 Vacuum Tube (Diode) directly-heated high-voltage rectifier 310 310A 316 317 360 453 502 502A 503 504 506 513 515 516 524 529 RM529 533 533A 535 536 543 543A 543B 545 545A 545B 547 551 555 556 560 561 561A 561S 564 567 570 575 581 581A 585 585A 647 647A
6080 154-0056-00 154-0315-00 Vacuum Tube (Dual Triode) dual power triode 132 160 316 317 516 535 535A RM35A 541 541A 535 536 545 545A 545B 546 547 549 565 567 575 581 581A 585 585A
6AN8 154-078 154-0078-00 Vacuum Tube (Triode/Pentode) triode-pentode combo 310 310A 316 317 360 502 502A 516 517 517A 526 565 570 575 N
6AQ5 154-017 154-0017-00 Vacuum Tube (Pentode) beam pentode 310 310A 316 360 507 511A 512 517 517A 524 536 570 575
6AU6 154-0022-00 157-0073-00 157-0059-00 154-0284-00 Vacuum Tube (Pentode) RF pentode 107 160 181 190 60 2A60 72 3A72 3C66 310 310A 316 317 360 502 502A 506 511 511A 512 513 516 517 517A 524 526 529 RM529 531 531A 535 536 545 545A 546 547 549 555 561 561A 561S 564 565 567 570 575 581 581A 585 585A 80 C CA Q
6BW4 154-0119-00 Vacuum Tube (Dual Diode) dual diode 126 502 502A 524 575
6CG7 154-0134-00 Vacuum Tube (Dual Triode) dual triode 3C66 575 Q
T0520 154-0093-00 154-0097-00 154-0102-00 154-0103-00 154-0129-00 154-0162-00 154-0176-00 154-0343-00 CRT 5" CRT 525 532 570 575