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 ÷1000 mode to detect leakage currents (of typical 1970s semiconductors, anyway).
|DUT drive voltage (C-E)||
|DUT current display||
|DUT connection||Three 4 mm jacks / binding posts|
- Matt Zimmerman, Oscilloscope to Curve Tracer with one Plug-in. In Tekscope Vol. 4 No. 6, Nov 1972.
- Tek 7CT1N @ amplifier.cd
- A homebrew test adapter
- Dennis Tillman: An Inexpensive Vacuum Tube Curve Tracer Adapter for All Tektronix Semiconductor Curve Tracers
- Tek 7CT1N @ barrytech.com
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, 0.25 W, 5%) to overheat and fail. C30 and C32 should be replaced with modern equivalents rated above 35 V.
|Year||Price||In 2022 Dollars|