123: Difference between revisions

Latest revision as of 03:38, 5 December 2023

Tektronix 123
miniature preamplifier Tek 123 front Produced from 1955 to (?) Manuals Tektronix 123 Instruction Sheet (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 μV_RMS, input-referred
Max. input	0.1 V_p-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

Description in 1958 Catalog
Front panel
Schematic
Parts list
Left side panel – circuit diagram
Right side panel – parts list
External view
internal view

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

@@ Line 15: / Line 15: @@
 The '''Tektronix 123''' is a miniature preamplifier [[introduced in 1955]].
-The gain is 100, input impedance is 10 MΩ, and output impedance is 31 kΩ. Frequency response is from 3 Hz to 25 kHz.
+It is intended to be used as an audio-frequency AC preamplifier for other instruments such as oscilloscopes.
+{{BeginSpecs}}
+{{Spec | Bandwidth       | 3 Hz to 25 kHz }}
+{{Spec | Voltage gain    | ×100 (40 dB) }}
+{{Spec | Noise           | ≤7.5 μV<sub>RMS</sub>, input-referred }}
+{{Spec | Max. input      | 0.1 V<sub>p-p</sub> }}
+{{Spec | Input impedance | 10 MΩ }}
+{{Spec | Output impedance| 31 kΩ }}
+{{Spec | Power           | One 1.345 V mercury battery (RM3R) and one miniature 30 V battery (413); 100 hours runtime }}
+{{EndSpecs}}
+==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.
-The intended use of the 123 is as a preamplifier for other instrumentation such as an oscilloscope, and the oscilloscope's input coupling can simply be set to "AC".
 ==Pictures==
@@ Line 29: / Line 42: @@
 Tek 123 schematic.png|Schematic
 Tek 123 partslist.png|Parts list
-Tek_123-2.jpg
+Tek_123-2.jpg | Left side panel – circuit diagram
-Tek_123-3.jpg
+Tek_123-3.jpg | Right side panel – parts list
 Tek_123-4.jpg
 Tek_123-5.jpg
@@ Line 38: / Line 51: @@
 </gallery>
+==Components==
 {{Parts|123}}
 [[Category:Amplifiers]]
 [[Category:Introduced in 1955]]