123

From TekWiki
Jump to navigation Jump to search
Tektronix 123
miniature preamplifier
Tek 123 front

Produced from 1955 to (?)

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

The Tektronix 123 is a miniature preamplifier introduced in 1955.

It is intended to be used as an audio-frequency AC preamplifier for other instruments such as oscilloscopes.

Key Specifications

Bandwidth 3 Hz to 25 kHz
Voltage gain  ×100 (40 dB)
Noise ≤7.5 μVRMS, input-referred
Max. input 0.1 Vp-p
Input impedance 10 MΩ
Output impedance 31 kΩ
Power One 1.345 V mercury battery (RM3R) and one miniature 30 V battery (413); 100 hours runtime

Prices

  • 50$ in 1960 (~$500 in 2023 dollars)

Internals

The 123 uses two CK512AX pentodes for amplification and is powered by batteries.

Although the 123 is an AC amplifier, the output is taken directly from the plate of one of the tubes, without an output coupling (DC block) capacitor. So the output signal rides on about 15 volts of DC.

Pictures

Components

Some Parts Used in the 123

Part Part Number(s) Class Description Used in
CK512AX 154-0114-00 Vacuum Tube (Pentode) flat-press subminiature pentode 123