213
The Tektronix 213 is a miniature portable oscilloscope introduced in 1975. It combines a 3½-digit DMM and a 1 MHz single channel scope in one unit. The maximum sweep rate is 0.4 μs/div with ×10 sweep magnifier.
The 213 provides true RMS voltage and current measurements. It is battery or AC line powered.
The 213 "Miniscope" was developed by a group led by Dave Allen, including John Pace, Gordon Meigs, Wendell Damm, Jim Knowlton (power supply) and others.
Key Specifications
| — Multimeter Section — | |
| DC Volts | 0.1 V to 1000 V, Input Resistance: 10 MΩ Accuracy, 0.1 V & 1 V: ±0.1%, ±3 counts; 10 V & 100 V: ±0.15%, ±1 count; 1000 V: ±0.2%, ±1 count |
| True RMS Volts | DC Volts |
| DC Current | 0.1 to 1000 mA Accuracy: 0.1 mA: ±0.5%, ±3 counts; 1 mA – 1000 mA: ±0.25%, ±3 counts |
| True RMS Current | 0.1 to 1000 mA Accuracy, 0.1 mA: ±2.5%, ±5 counts (DC); ±1.5%, ±5 counts (40 Hz – 4 kHz); ±4.5%, ±5 counts (4 kHz − 40 kHz); 1 mA – 1000 mA: ±2.5%, ±5 counts (DC); ±1.5%, ±5 counts (40 Hz – 4 kHz); ±3.5%,±5 counts (4 kHz − 40 kHz) |
| Current range input resistance | 0.1 mA: 1000 Ω; 1 mA: 100 Ω; 10 mA: 10.2 Ω; 100 mA: 1.2 Ω; 1000 mA: 0.3 Ω |
| Resistance | 1 KΩ: ±0.5%, ±3 counts; 10 KΩ – 1 MΩ: ±0.5%, ±1 count; 10 MΩ: ±1%, ±1 count |
| — Oscilloscope Section — | |
| Voltage ranges | 5 mV/Div to – 100 V/Div, ±3% |
| Bandwidth (Voltage) | DC – 1 MHz (at 10 mV/Div and below, 400 kHz) |
| Current ranges | 5 µA/Div to 100 mA/Div, ±3% |
| Bandwidth (Current) | DC – 200 kHz (5 µA/Div – 10 μA/Div); DC – 400 kHz (20 μA/Div – 200 mA/Div) |
| Input resistance | 10 MΩ // 150 pF (5 mV/Div – 1 V/Div), 100 pF (2 V/Div to – 100 V/Div) |
| Rise time | 875 ns (5 mV/Div – 10 mV/Div); 350 ns (20 mV/Div – 100 V/Div) |
| Sweep | 500 ms/Div – 2 µs/Div, ±5% (magnified or unmagnified) |
| Batteries | 2 × “D” NiCd cells |
| Operating time | 3.5 hours typical at maximum intensity after full charge cycle |
| Charge time | 16 h |
| Mains power | 90 – 136 VAC. 48 – 62 Hz (Option 1: 180 – 250 VDC. or 180 – 250 VAC, 48 – 62 Hz) |
| Power consumption | Less than 8 watts |
Links
- David Allen, The Birth of the Miniscope @ VintageTek.org
- EEVblog #628 – Tektronix 213 Vintage Portable Oscilloscope Teardown Video and Photo Set
- Tektronix 213 DMM Repair Progress video
Documents Referencing 213
| Document | Class | Title | Authors | Year | Links |
|---|---|---|---|---|---|
| Tekscope 1975 V7 N1.pdf | Article | A Hand-held DMMiniscope | Dave Allen | 1975 | 213 |
Prices
| Year | 1976 | 1977 | 1980 | 1982 | 1986 |
|---|---|---|---|---|---|
| Catalog Price | $1,200 | $1,425 | $1,750 | $2,100 | $2,830 |
| In 2023 Dollars | $6,500 | $7,200 | $6,500 | $6,700 | $7,900 |
Internals
The 213 makes use of two Tek-made custom chips, the 155-0048-01 trigger sweep circuit, and the 155-0114-00 7-segment character generator in the DVM circuit. In addition, it includes some standard opamps (741, 324) and a 4-digit decimal counter (Mostek MK5007).
Pictures
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Tek 213 front
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In DMM mode
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Tek 213 size comparison with 500 series plug-in bay (in a 585)
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213 with pouch
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right side
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without covers, bottom/left
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without covers, left
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without covers, top
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without covers, operating, top/right
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213_amplifier_board
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213_bottom_view
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213_closeup_CRT_drive
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Plastic case halves
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Original battery, corroded
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In DMM mode
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In scope mode
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Catalog image, front
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Catalog image, side
Schematics
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Attenuator and Input Amplifier Schematic
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GM and RMS Converter Schematic
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Battery Charger and Power Supply Schematic
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HV and CRT Schematic
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A-D Converter and Character Generator Schematic
