475

The Tektronix 475 is a portable dual-trace oscilloscope with dual time-bases similar to the 465, but with 200 MHz bandwidth and a maximum vertical sensitivity of 2 mV/Div. It is all solid-state except for the CRT. It was introduced in November 1972.

Manuals – Specifications – Links – Pictures

The military variant is called OS-261 C(v)1/0, which has a DC/DC converter (12/24V input) on board.

A revised version, the 475A (introduced in 1977), has 250 MHz bandwidth and a maximum vertical sensitivity of 5 mV/Div.

The 1106 is a battery pack for the 475.

The optional DM44 multimeter attaches to the top of the instrument.

From Tekscope Vol. 4 No. 5, 1972:

Electrical design team [...] for the 475 under the leadership of Jim Hinze was: Jim Godwin, Les Larson, Steve Tosh, and Jim Woo.

Key Specifications

Bandwidth	200 MHz (475), AC cutoff 10 Hz, switchable BW limit 20 MHz, SN B100000+ also 100 MHz
Rise time	1.75 ns (475)
Deflection	2 mV/Div to 5 V/Div, 1−2−5; 400 μV/Div, 50 MHz with CH1 input connected to CH2 VERT SIG OUT
Time base	10 ns/Div to 500 ms/Div, 1−2−5, and ×10 magnifier
Input impedance	1 MΩ // 20 pF
Triggering	0.3 Div (int) or 50 mV (ext) to 40 MHz, increasing to 1.5 Div/250 mV at 200 MHz; AC coupling >60 Hz; LF REJ >50 kHz, HF REJ <50 kHz
X bandwidth	3 MHz
Z axis input	5 Vp-p, 50 MHz
Calibrator	1 kHz, 30 mA / 300 mV square wave
Outputs	CH2 Vert Signal Out, 20 mV/Div into 1 MΩ or 10 mV/Div into 50 Ω; A and B +GATE OUT, +5 V; Probe power jack
CRT	8 × 10 cm², P31 phosphor (P11 opt.), 154-0677-00
Power	110, 115, 120, 220, 230 or 240  VAC ±10%, 48-440 Hz, max. 100 W

Links

• Lazy Electrons Tektronix 475A & DM44 Repair Page
• The New Look in Portables, in Tekscope Vol. 4 No. 5, 1972
• Tek 475 / Tek 475A @ amplifier.cd
• Tek 475A / DM44 repair by vintageTek Museum @ YouTube
• Tek 475A in operation @ YouTube
• Tektronix 475A and DM44 Repair Power Supply and Logic by Zenwizard Studios @ YouTube
• Tektronix 475A and DM44 Power Supply and Tube Alignment @ Zenwizard Studios YouTube
• 151-0367-00 Guaranteed Bad Parts (This might be bad advice) @ Zenwizard Studios YouTube
• Tektronix 475A Vertical Alignment and One Last Power Supply Issue @ Zenwizard Studios YouTube
• Tektronix 475A Trigger Section Alignment @ Zenwizard Studios YouTube
• Tektronix DM44 & 475A Horizontal Alignment by Zenwizard Studios @ YouTube
• Tektronix 475 non A Repair and Restoration by Zenwizard Studios @ YouTube
• Tektronix 475A Power Supply and Scope Repair (With Soldering) by Zenwizard Studios @ YouTube
• Tektronix 475A Trigger Transistor Testing 151 0367 00 by Zenwizard Studios @ YouTube

Documents Referencing 475

Document	Class	Title	Authors	Year	Links
Tekscope 1972 V4 N5 Sep 1972.pdf	Article	The New Look in Portables		1972	465 • 475
Tekscope 1974 V6 N5.pdf	Article	Understanding oscilloscope trigger controls		1974	475 • 7B70

Internals

The 475 uses a number of Tek-made integrated circuits, including the 155-0032-01 input preamplifier, 155-0085-00 input amplifier, 155-0078-00 vertical amplifier, 155-0091-00 channel switch, 155-0082-00 vertical output amplifier, and 155-0049-00 sweep control.

Prices

Year	1973	1076	1983
Catalog Price	$2,500	$2,900
In 2023 Dollars	$17,300	$15,700

Common Problems

• See 475/Repairs

Pictures

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  Tek 475 in mixed sweep ("MIX") horizontal mode

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  475

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  475 rear

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  475

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  475 (OS-261 C) rear, with DC-Input

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  475/DM44 measuring a 1 kHz sine wave

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  475/DM44 measuring a 10 kHz sine wave

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  475/DM44 measuring a 100 kHz sine wave

475A

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  Tektronix 475A

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  Tektronix 475A

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  475A with DM44

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  475A with DM44

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  475A Time/Frequency Measurement with DM44, HP Frequency Counter used for Verifying DM44 Output.

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  475A rear

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  475A A9 Interface board

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  475A A6 & Fan Motor

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  475A A7 Timing board

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  475A Power Supply Section of A9

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  475A with DM44 Board on top

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  475A A3 Vertical Preamp board

475M

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Components