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Power Supplies for the Tektronix Type 131 Model 4 Current Probe Amplifier

Each of these has a Tektronix proprietary coaxial output connector. While the connectors on the power supplies for the 131 and 134 are identical, the power supplies are NOT interchangeable due to different grounds.

The Tektronix 015-027 is the 115 VAC power supply for the Tektronix 131 Model 4. It has a standard NEMA 5-15 AC power plug built onto the body of the power supply. It has a full wave rectified output which is filtered and Zener regulated to ~20 VDC.

The Tektronix 015-028 is the 230 VAC power supply for the Tektronix 131 Model 4. It is identical to the 115 VAC version except for the cover, which has a different part number and voltage rating printed on it, and a metal extension of the body to accommodate the addition of two dropping resistors (18 kΩ, 1 W) in series with the transformer primary. Oddly, this 230 VAC version appears to use a NEMA 5-15 115 VAC cord and plug. The addition of the two series resistors allows it to work from 210 to 250 VAC.

For the two above, the center conductor is grounded and the outer conductor is about 20 volts negative.

The Tektronix 013-050 (013-0050-00) battery adaptor, allows the Type 131 Model 4 to be powered from any 22.5 V battery capable of delivering 10 mA. This power supply alternative is shown at the bottom center of the photo preceding page 1-1 of the 131 manual. Note that, due to the complete absence of ground connections, this accessory may also be used for the Type 134 as long as the battery is capable of delivering ~70 mA.

Note the added label in the second photo, intended to prevent accidental use with a Type 134. The 015-027 power supplies did not originally come with any identifying label associating them with the 131. Using the wrong supply with the 131 or 134 will short out the power supply, possibly leading to damage of the power supply. Damage to the amplifier is unlikely.