3A2
The Tektronix Type 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 |
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
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3A2 Front
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3A2 Left
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3A2 Right
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3A2 Top
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3A2 Bottom
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3A2 Channel 1 Input Amp
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3A2 Channel 2 Input Amp
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3A2 Switching and Output Amp
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3A2 Attenuator Switches
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 • Keithley 610B |
| 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 | 067-506 • 111 • 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 |