7CT1N
Template:Plugin Sidebar 2 The Tektronix 7CT1N is a curve tracer plug-in for 7000-series scopes. The 5CT1N plug-in for 5000-series scopes is very similar.
It can be installed in either a vertical or a horizontal compartment, a front-panel switch must be set accordingly. A pull-out cable with a plastic BNC plug connects to the input of a module installed in the corresponding plugin for the other axis, with a fixed 100 mV/Div scaling compatible with time base X inputs.
Internally, a variable-amplitude 55 Hz triangle-wave source supplies a transformer to step up the drive voltage and decouple it from ground (Emitter terminal). A step source supplies base current or gate voltage to the DUT. The amplifier for the current axis can be switched into a x1000 mode to detect leakage currents (of typical 1970s semiconductors, anyway).
Key Specifications
DUT drive voltage (C-E) |
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DUT current display |
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Base/Gate drive |
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DUT connection | Three 4 mm jacks / binding posts |
DUT adapters |
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Links
- Tekscope Vol. 4 No. 6, Nov 1972
- Tek 7CT1N @ amplifier.cd
- Tek 7CT1N @ barrytech.com
- A homebrew test adapter
Common Problems
C30 and C32 (100 μF, 25 V) are under-rated and therefore have a tendency to leak or short, causing associated resistors R30 and R32 (240 Ω, 0.25W, 5%) to overheat and fail. C30 and C32 should be replaced with modern equivalents rated above 35 V.
Prices
Year | Price | 2015 value |
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1971 | $400 | $2,320 |
1980 | $1,000 | $2,870 |
1990 | $2,100 | $3,790 |
Pictures
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7CT1N front
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7CT1N left side
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7CT1N right side
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7CT1N tracing a BC337