3B1: Difference between revisions

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The Tektronix 3B1 is a timebase plug-in [[introduced in 1962]] for [[560-series scopes]].   
{{Plugin Sidebar 2 |
10MHz is is the maximum trigger frequency.
title=Tektronix 3B5 |
summary=10 MHz time base |
image=3b1 front.jpg |
caption=Tektronix 3B1 front |
introduced=1962 |
discontinued=(?) |
series=[[560-series scopes]] |
manuals=
* [http://w140.com/tek_3b1.pdf Tektronix 3B1 Manual (PDF)]
}}
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.
The calibrated sweep rates go from 1 s/Div to 500 ns/Div.
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
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The DC voltage is made by a [[ZZ1000]] 80 V reference passed through  
The DC voltage is made by a [[ZZ1000]] 80 V reference passed through  
a potentiometer-variable voltage divider.   
a potentiometer-variable voltage divider.   
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.


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


<gallery>
<gallery>
Image:3b1 front.jpg|Front  
File:3b1 front.jpg|Front  
Image:3b1 left.jpg|Left
File:3b1 left.jpg|Left
Image:3b1 right.jpg|Right
File:3b1 right.jpg|Right
Image:3b1 bottom.jpg|Bottom
File:3b1 bottom.jpg|Bottom
Image:3b1 top.jpg|Top
File:3b1 top.jpg|Top
Image:3b1 cat3.jpg|In 1965 Catalog
File:3b1 cat3.jpg|In 1965 Catalog
File:3b1 normal trigger.png|Normal trigger circuit
File:3b1 normal trigger.png|Normal trigger circuit
File:3b1 delayed trigger.png|Delated trigger circuit
File:3b1 delayed trigger.png|Delated trigger circuit

Revision as of 10:39, 21 August 2014

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. 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.