3B1: Difference between revisions
No edit summary |
No edit summary |
||
| Line 48: | Line 48: | ||
3b1 horizontal amp.png|Horizontal amp circuit | 3b1 horizontal amp.png|Horizontal amp circuit | ||
</gallery> | </gallery> | ||
{{Parts|3B1}} | |||
[[Category:560 series plugins]] | [[Category:560 series plugins]] | ||
Revision as of 14:29, 10 October 2021
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
-
Front
-
Left
-
Right
-
Bottom
-
Top
-
In 1965 Catalog
-
Normal trigger circuit
-
Delayed trigger circuit
-
Delay pickoff circuit
-
Normal sweep circuit
-
Delayed sweep circuit
-
Horizontal amp circuit
