125
The Tektronix 125 is a power supply introduced in 1961 for the Type 122 preamplifier. The 125 runs on wall power (mains) and provides three regulated outputs:
- +135 VDC at 0-20 mA, 1 mV ripple, tube-based regulation
- -90 VDC at 0-20 mA, 1 mV ripple, tube-based regulation
- -6 VDC at 0.7-4 A, 4 mV ripple, transistor-based regulation
The +135 V section contains an OG3 voltage reference tube. The -90 V and -6 V sections use the +135 V supply as their reference. All power rectification is done with semiconductor diodes.
A calibration fixture, the 067-0528-00, exists for testing the 125.
The 125, like the 122, appears in three form factors:
- 125 (standard, vertical orientation, no mounting ears)
- RM125 (rack mount, horizontal orientation, with wide front panel for mounting mounting in a standard 19" rack, later called "R125")
- FM125 (frame mount, vertical orientation, for use in the 014-002 mounting frame, later called "F125")
Pictures
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Schematic
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RM125 Front
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RM125 Internal Top View
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RM125 Internal Underside
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RM125 Rear
Some Parts Used in the 125
| Part | Part Number(s) | Class | Description | Used in |
|---|---|---|---|---|
| 6G11 | 154-0660-00 | Vacuum Tube (Pentode) | double sharp cut-off beam power pentode | 125 • 132 • 519 • 067-0502-01 • 050-0551-00 |
| 6GE8 | 154-0260-00 | Vacuum Tube (Triode/Pentode) | triode-pentode combo | 125 • 132 • 560 |
| 7734 | 154-260 • 154-0260-00 | Vacuum Tube (Triode/Pentode) | triode-pentode combo | 125 • 132 |