The Tektronix Type O is a letter-series plug-in, designed by Hiro Moriyasu, that contains two operational amplifiers and a vertical amplifier. It was introduced in mid-1962 and was available through 1973.

Tektronix Type O
Dual opamp plugin
Type O front view

Compatible with 500-series scopes

Produced from 1962 to 1974

Manuals

The input and feedback networks of the operational amplifiers can be configured from the front panel switches and/or by way of user-supplied components plugged into the front panel banana jacks. Tektronix made several pre-configured plug-in modules to plug directly into those jacks. See the Accessories section below. Note that one of the accessories is an empty box with mating banana plugs for a user-designed circuit.

A mode switch selects the display to be taken from either op-amp's output, or the vertical amplifier input.

Key Specifications

Bandwidth DC to 25 MHz (Vertical amplifier1)
Rise time 14 ns (Vertical amplifier 1)
Deflection 50 mV/div to 10 V/div, 1–2–5, and variable (Vertical amplifier)
Input 1 MΩ // 47 pF (Vertical amplifier)
Op-Amp GBW 15 MHz
Op-Amp gain 2500
Op-Amp output ±50 V, ±5 mA; output impedance 30 Ω @ 1 MHz
Op-Amp noise typ. 0.5 mVp-p referred to the input
Internal Z input and feedback can be selected from 10 kΩ, 100 kΩ, 200 kΩ, 500 kΩ, 1 MΩ
or 10 pF to 1 μF in decade steps

Note 1: In 540- and 580-series scopes and 555

Accessories

Prices

  • $625 in 1971 ($4,700 in 2023 dollars)

Internals

The opamps are implemented using two 12AU6 as a differential pair followed by two systems of a 6DJ8 as a bootstrapped cathode follower.

The vertical amplifier also starts with a 12AU6 differential pair, which is followed by a pair of 2N1143 200 MHz transistors.

Pictures

Schematics

Components

Some Parts Used in the O

Part Part Number(s) Class Description Used in
12AU6 154-0040-00 Vacuum Tube (Pentode) RF pentode 81 112 1L10 1L20 1L60 3L10 512 556 575 545 547 549 581 585 A B C G K H L ML M N O R S Z
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
8426 Vacuum Tube (Pentode) RF pentode O 545A 547 549 581A 585A