475: Difference between revisions

Revision as of 01:47, 26 November 2020

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Portable 200 MHz dual-trace scope

Produced from 1972 to 1983

Manuals

475

475A

Modifications

History

(All manuals in PDF format unless noted otherwise)

Manuals – Specifications – Links – Pictures

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.

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 V_p-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 V_AC ±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

Tektronix 475A
Tektronix 475A
Tek 475 in mixed sweep ("MIX") horizontal mode
475A with DM44
475
475 rear
475A with DM44
475
475A Time/Frequency Measurement with DM44, HP Frequency Counter used for Verifying DM44 Output.
475A rear
475 (OS-261 C) rear, with DC-Input
475A A9 Interface Board
475A A6 & Fan Motor
475A Power Supply Section of A9
475A with DM44 Board on top
475A A3 Vertical Preamp Board
475/DM44 measuring a 1 kHz sine wave
475/DM44 measuring a 10 kHz sine wave
475/DM44 measuring a 100 kHz sine wave

@@ Line 17: / Line 17: @@
 '''475A'''
 * [[Media:070-2163-00.pdf|Tektronix 475A-DM44 Oscilloscope Instruction Manual (OCR, PDF)]]
-* [[Media:070-2162-00.pdf|Tektronix 475A Manual (11MB, PDF)]]
+* [[Media:070-2162-00.pdf|Tektronix 475A Service Manual (11MB, PDF)]]
 * [[Media:tek_475a_block_diagram.pdf|Tektronix 475A Schematics (PDF, OCR, bad-OCR)]]
 * [http://w140.com/tek_475a_schematics.pdf  Tektronix 475A Schematics (PDF)]