3B1: Difference between revisions

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The Tektronix 3B1 is a timebase plug-in [[introduced in 1962]] for [[560-series scopes]].   
The Tektronix 3B1 is a timebase plug-in [[introduced in 1962]] for [[560-series scopes]].   
10MHz is is the maximum trigger frequency.
The calibrated sweep rates go from 1 sec/div to 500 nsec/div.
The calibrated sweep rates go from 1 sec/div to 500 nsec/div.
There is a switch that enables 5X horizontal magnification,  
There is a switch that enables 5X horizontal magnification,  
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and a regular sweep.  The 3B1 uses vacuum tubes, bipolar junction transistors,
and a regular sweep.  The 3B1 uses vacuum tubes, bipolar junction transistors,
and [[tunnel diodes]].
and [[tunnel diodes]].
The trigger input goes through the int/ext switch and then the ac/dc coupling
switch, and then a [[7895]] cathode follower.  The output of the cathode follower
drives one base of a [[2N2207]] PNP differential amplifier which has a tunnel diode
in the collector load.  The tunnel diode generates pulses when it switches back
and forth between its two stable voltages, which are capacitively coupled to a
[[2N2501]] NPN common emitter amplifier.


* [http://w140.com/tek_3b1.pdf Tektronix 3B1 Manual (PDF)]
* [http://w140.com/tek_3b1.pdf Tektronix 3B1 Manual (PDF)]

Revision as of 18:26, 19 May 2012

The Tektronix 3B1 is a timebase plug-in introduced in 1962 for 560-series scopes. 10MHz is is the maximum trigger frequency. The calibrated sweep rates go from 1 sec/div to 500 nsec/div. There is a switch that enables 5X horizontal magnification, which makes the fastest sweep 100 nsec/div. The 3B1 has a delayed sweep and a regular sweep. The 3B1 uses vacuum tubes, bipolar junction transistors, and tunnel diodes.

The trigger input goes through the int/ext switch and then the ac/dc coupling switch, and then a 7895 cathode follower. The output of the cathode follower drives one base of a 2N2207 PNP differential amplifier which has a tunnel diode in the collector load. The tunnel diode generates pulses when it switches back and forth between its two stable voltages, which are capacitively coupled to a 2N2501 NPN common emitter amplifier.