3B1: Difference between revisions

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There is a switch that enables 5 × horizontal magnification,  
There is a switch that enables 5 × horizontal magnification,  
which makes the fastest sweep 100 ns/Div.  The 3B1 has a delayed sweep
which makes the fastest sweep 100 ns/Div.  The 3B1 has a delayed sweep and a regular sweep.   
and a regular sweep.  The 3B1 uses vacuum tubes, bipolar junction transistors,
 
and [[tunnel diodes]].
{{MissingSpecs}}
 
==Internals==
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
The trigger input goes through the int/ext switch and then the ac/dc coupling
Line 34: Line 37:
When the sweep ramp exceeds the control voltage, a 2.2 mA tunnel diode in the
When the sweep ramp exceeds the control voltage, a 2.2 mA tunnel diode in the
plate load of the differential amplifier switches state.
plate load of the differential amplifier switches state.
==Specifications==
[[Category:Specifications needed]]''please add''


==Pictures==
==Pictures==
<gallery>
<gallery>
File:3b1 front.jpg|Front  
3b1 front.jpg|Front  
File:3b1 left.jpg|Left
3b1 left.jpg|Left
File:3b1 right.jpg|Right
3b1 right.jpg|Right
File:3b1 bottom.jpg|Bottom
3b1 bottom.jpg|Bottom
File:3b1 top.jpg|Top
3b1 top.jpg|Top
File:3b1 cat3.jpg|In 1965 Catalog
3b1 cat3.jpg|In 1965 Catalog
File:3b1 normal trigger.png|Normal trigger circuit
3b1 normal trigger.png|Normal trigger circuit
File:3b1 delayed trigger.png|Delated trigger circuit
3b1 delayed trigger.png|Delayed trigger circuit
File:3b1 delay pickoff.png|Delay pickoff circuit
3b1 delay pickoff.png|Delay pickoff circuit
File:3b1 normal sweep.png|Normal sweep circuit
3b1 normal sweep.png|Normal sweep circuit
File:3b1 delayed sweep.png|Delayed sweep circuit
3b1 delayed sweep.png|Delayed sweep circuit
File:3b1 horizontal amp.png|Horizontal amp circuit
3b1 horizontal amp.png|Horizontal amp circuit
</gallery>
</gallery>


[[Category:560 series plugins]]
[[Category:560 series plugins]]

Revision as of 11:15, 26 September 2017

Template:Plugin Sidebar 2 The Tektronix 3B1 is a time-base plug-in introduced in 1962 for 560-series scopes. 10 MHz is is the maximum trigger frequency. The calibrated sweep rates go from 1 s/Div to 500 ns/Div.

There is a switch that enables 5 × horizontal magnification, which makes the fastest sweep 100 ns/Div. The 3B1 has a delayed sweep and a regular sweep.

Key Specifications

  • please add

Internals

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.

The delay pickoff circuit is a 6DJ8 differential amplifier that compares the sweep ramp voltage with a knob-controlled DC voltage which determines the point where the delayed trigger starts. The DC voltage is made by a ZZ1000 80 V reference passed through a potentiometer-variable voltage divider.

When the sweep ramp exceeds the control voltage, a 2.2 mA tunnel diode in the plate load of the differential amplifier switches state.

Pictures