3B1

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Tektronix 3B1
10 MHz time base plug-in
Tektronix 3B1

Compatible with 560-series scopes

Produced from 1962 to (?)

Manuals
Manuals – Specifications – Links – Pictures

The Tektronix 3B1 is a time-base plug-in introduced in 1962 for 560-series scopes. It is compatible with all the members of the 560 scope family other than the 560 itself.

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

Trigger Frequency DC to 10 MHz
Sweep Speeds 1 Sec/div to 0.5  μs/div in 20 1-2-5 steps
Sweep Types Normal and Delayed
Sweep Magnification x5

Links

Documents Referencing 3B1

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

Components

Some Parts Used in the 3B1

Part Part Number(s) Class Description Used in
1N3714 152-0081-00 Discrete component 2.2 mA, 25 pF germanium tunnel diode 546 547 556 21A 22A 3B1 3B2 3B3 422 491 283
2N2207 151-063 151-0063-00 Discrete component germanium PNP transistor 3B1 3B3 3S76 321A 547
6AL5 154-016 154-0016-00 154-0038-00 Vacuum Tube (Dual Diode) high-perveance dual diode 163 181 190 1M1 310 310A 315 316 317 3B1 3B1S 3B2 3B3 3B5 502 502A 503 511 511A 512 516 517 517A 524 526 535 535A 545 545A 549 551 565 570 581 581A 585 585A C T Telequipment D56 Telequipment S52
6BL8 154-0278-00 Vacuum Tube (Triode/Pentode) triode-pentode combo 67 2B67 3B1 3B1S 3B2 3B3 3B4 503 504 506 516 549 561 561A 561S 564 565 567 Telequipment D52 Telequipment D56 Telequipment S31 Telequipment S32 Telequipment S32A Telequipment S51 Telequipment S52
6DJ8 154-0187-00 154-0305-00 Vacuum Tube (Dual Triode) dual triode 132 161 310A 316 317 502 502A 503 504 506 515 516 519 526 529 RM529 533 535 536 543 544 545 545A 545B 546 547 549 555 556 561A 561S 564 565 567 581 581A 585 585A 661 1A4 1S1 60 2A60 63 2A63 67 2B67 3A1 3A1S 3A2 3A3 3A6 3A7 72 3A72 75 3A75 4S2 51 3B1 3B1S 3B2 3B3 3B4 3M1 3S76 3T77 3T77A 9A1 9A2 1121 80 81 82 86 B O W Z Telequipment D56 Telequipment S32A Telequipment D52 S-311 Telequipment TD51 Telequipment S52 Telequipment S51 Telequipment Type A TU-4
7895 154-0378-00 Vacuum Tube (Triode) Nuvistor Triode 3B1 3B1S 3B3
RT5204 151-0058-00 Discrete component Silicon NPN transistor 565 RM565 Z 2A61 3B1 3B3 3S76 3T77
ZZ1000 154-370 154-0370-00 Gas Discharge Tube (Voltage regulator) 81 V voltage reference 129 3B1 3B1S 3B2 3B3 3S76 422 S-311