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

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

A revised version, the 475A, 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.

Key Specifications

Bandwidth	200 MHz (475), AC cutoff 10 Hz, switchable BW limit 20 MHz
Rise time	1.75  ns (475)
Deflection	2 mV/Div to 5 V/Div, 1-2-5
Cascaded mode	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.)
Power	110, 115, 120, 220, 230 or 240  VAC ±10%, 48-440 Hz, max. 100 W

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.

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 in operation @ YouTube
• Handle Replacement Modification Kit

Common Problems

• See 475/Repairs

Pictures

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  Tektronix 475A

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  Tektronix 475A

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

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  475A with DM44

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  475

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  475 rear

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  475A with DM44

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  475

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

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  475A A9 Interface Board

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  475A A6 & Fan Motor

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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

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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

475M

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