7CT1N: Difference between revisions

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(year 1971 per September 1971 "new products" brochure)
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* [http://amplifier.cd/Test_Equipment/Tektronix/Tektronix_7000_series_special/7CT1N_curve_tracer.htm Tek 7CT1N @ amplifier.cd]
* [http://amplifier.cd/Test_Equipment/Tektronix/Tektronix_7000_series_special/7CT1N_curve_tracer.htm Tek 7CT1N @ amplifier.cd]
* [http://www.barrytech.com/tektronix/tek7000/tek7ct1n.html Tek 7CT1N @ barrytech.com]
* [http://www.barrytech.com/tektronix/tek7000/tek7ct1n.html Tek 7CT1N @ barrytech.com]
* [http://www.antiqueradios.com/forums/viewtopic.php?f=8&t=177192 A homebrew test adapter]


==Common Problems==
==Common Problems==

Revision as of 10:24, 20 April 2015

Template:Plugin Sidebar 2 The Tektronix 7CT1N is a curve tracer plug-in for 7000-series scopes. 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)
  • positive (NPN or N channel) or negative (PNP or P channel) half-waves
  • 7.5 V, 0.5 V/Div, 240 mA peak
  • 30 V, 2 V/Div, 60 mA peak
  • 75 V, 5 V/Div, 24 mA peak
  • 300 V, 20 V/Div, 6 mA peak
  • HV warning light on for > 50 V
  • peak power 500 mW
DUT current display
  • 10 μA/Div to 20 mA/Div, 1-2-5 steps (x 1 mode)
  • 10 nA/Div to 20 μA/Div, 1-2-5 steps (x 1000 mode)
Base/Gate drive
  • 0 to at least 10 steps
  • dual polarity
  • variable offset, at least +/- 5 steps
  • current mode: 1 μA/Step to 1 mA/Step in 1-2-5 sequence
  • voltage mode: 1 mV/Div to 1 V/Div in 1-2-5 sequence, 1 kΩ current limit
DUT connection Three 4 mm jacks / binding posts

Links

Common Problems

C30 and C32 (100 μF, 25 V) have a tendency to leak or short, causing associated resistors R30 and R32 (240 Ω, .25W, 5%) to overheat and fail.

A good preventive maintenance procedure would be to replace these two capacitors with modern equivalents. Three 7CT1N units purchased online had this fault, and replacement of the capacitors and resistors restored proper operation.

Prices

Year Price 2015 value
1971 $400 $2,320

Pictures