3A2

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Tektronix 3A2
500 kHz dual-trace amplifier plug-in
Type 3A2 Front View

Compatible with 560-series scopes

Produced from 1964 to 1974

Manuals

Alternate copy

(All manuals in PDF format unless noted otherwise)
Manuals – Specifications – Links – Pictures

The Tektronix 3A2 is a 500 kHz dual-trace amplifier plug-in introduced in 1963 for 560-series scopes. It was designed for compatibility with the digital unit in the 567, e.g, the 6R1 or 6R1A.

Key Specifications

Bandwidth 500 kHz
Input impedance 1 MΩ // 47 pF
Deflection 10 mV/div to 25 V/div

Links

Documents Referencing 3A2

Internals

The input signal passes through compensated attenuators and then into a 12AT7 cathode-follower stage. Channel switching in ALTERNATE mode is done using diodes. The output stage that drives the vertical deflection plates of the scope uses a pair of 6BA8 pentodes.

The "CHOP" mode of the 3A2 switches back and forth between the two inputs at a rate of a few kilohertz. The signal that causes the switching is generated by a relaxation oscillator formed using a capacitor and a pair of 152-108 Shockley diodes, D385 and D386.

Pictures

Components

Some Parts Used in the 3A2

Part Part Number(s) Class Description Used in
12AL5 154-0038-00 Vacuum Tube (Double Diode) high-perveance dual diode 3A2 3B2 545 545A 549 N
12AT7 154-0039-00 Vacuum Tube (Dual Triode) dual high-gain triode 161 180 310 310A 315 316 360 502 502A 511A 512 513 513D 514 514AD 514D 516 524 529 RM529 544 546 547 556 565 570 3A2 75 3A75 1M1 A B C G H K L ML M N K R S Z
4E50-28 152-108 152-0108-00 Discrete component Shockley diode (four-layer diode) 3A2
6BA8 154-0163-00 Vacuum Tube (Triode/Pentode) triode-pentode combo 59 2A61 72 3A72 3A2
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