Tektronix 2A63 (63) 300kHz Differential Comparator (1969)

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Quick Specifications / Photos
Detailed Specifications
Operating Instructions
Misc. Part Numbers

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$175 (1969)
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QUICK SPECS / PHOTOS
  • Bandwidth : DC to 300 kHz
  • Sensitivity : 1 mV/div to 20 V/div
  • Risetime : 1 µsec
  • Input Impedance : 1 MegΩ ,47 pf

    SPECIFICATIONS

    The Type 2A63 Differential Amplifier module is designed for use with Tektronix Type 560-Series Oscilloscopes. It has a bandpass of dc to 300 kc or greater and a differential rejection ratio of approximately 50 to 1 or better, depending upon frequency and sensitivity (Rejection ratios as high as 2000 to 1 can be obtained through the use of two Tektronix Type P6023 attenuator probes). Sensitivity is variable in 14 calibrated steps from 1 millivolt to 20 volts per division of deflection, and is continuously variable (uncalibrated) between steps and up to 50 volts per division. Accuracy is within 3% of each of the calibrated steps. In addition to differential operation, the module can also be used for single-ended operation. The input impedance at both inputs is one megohm paralleled by 47 picofarads. Maximum allowable signal voltage at the INPUT connectors is 600 volts (dc plus peak ac).

    A Type 2A63 module can be used with a Type 2A60 or Type 3A75 module, or another Type 2A63, in the same Type 560 series Oscilloscope to measure the phase relationship between two sine waves. Phase measurements accurate to within 1° at 50 kc can be made with two properly calibrated Type 2A63 modules.

    above excerpts from Tektronix Type 2A63 Instruction Manual
    OPERATING INSTRUCTIONS
    Throughout the instructions that follow, it is assumed, unless otherwise noted, that the Type 2A63 module is inserted in the Y-axis opening ot a Type 560-Series Oscilloscope, thereby providing vertical deflection of the oscilloscope trace. If the module is inserted in the X-axis opening of the oscilloscope, it will provide horizontal deflection and the instructions must be interpreted accordingly, It is further assumed throughout the discussion that there is a time-base module in the X-axis opening of the oscilloscope.

    Signal Connections

    When a single signal input is used with the Type 2A63 module, it may be applied to either the +INPUT connector or the -INPUT connector. If the signal is connected to the +INPUT connector, the -INPUT AC-DC-GND switch should be placed in the GND position and the +INPUT AC-DC-GND switch should be placed in the AC or DC position, depending upon the type of coupling desired. If the signal is connected to the -INPUT connector, the +INPUT AC-DC-GND switch should be placed in the GND position and the -INPUT AC-DC-GND switch should be placed in the AC or DC position. If the signal is applied to the -INPUT connector, the display on the oscilloscope screen will be opposite in polarity to a normal presentation. Conventionally, a normal display places the more positive portions of a waveform in the vertical channel toward the top of the screen and the more positive portions of a waveform in the horizontal channel toward the right side of the screen.

    When it is desired to display the difference between two signals, one signal is connected to each INPUT connector and both AC-DC-GND switches are placed in either the AC or DC position. In this mode of operation, the two signals are subtracted from each other algebraically, and the difference is displayed as a single trace on the oscilloscope screen. This is called the differential mode of operation. It permits you to eliminate signals which are common to both inputs and to observe a waveform which is peculiar to one.

    Use of the differential mode of operation is limited to signals of about ± 5 volts maximum at the input to the first amplifier stage of the module. For this reason, the common mode signal at the INPUT connectors should be limited to about ± 5 volts when the VOLTS/DIV. switch is set at any position from 1 mVOLTS through .2 VOLTS and to about ± 50 volts when the VOLTS/DIV. switch is set at .5, 1, or 2 VOLTS. In the 5, 10, and 20 VOLTS positions of the VOLTS/DIV. switch, the common-mode signal at the INPUT connectors may be as high as ± 200 volts.

    Displaying a Signal

    To display a signal with the Type 2A63 module, proceed as follows:

    1. Connect the signal to one or both INPUT connectors.

    2. Establish a common ground between the oscilloscope and the signal source. This can be done by connecting the ground clip on a Textronix attenuator probe to signal ground.

    3. Adjust the time-base controls to obtain a stable display.

    4. Set the VOLTS/DIV. switch and the POSITION control so that the signal is placed as desired on the graticule. In general, if you are interested only in the ac component of the signal, you should set the appropriate AC-DC-GND switch to AC; if you are interested in the dc level of the signal, you should set the appropriate AC-DC-GND switch to DC. An exception to this is in observing low-frequency signals, When the AC-DC-GND switch is in the AC position, and the AC STABILIZED switch is in the OFF position, the lower bandpass limit (3-db point) of the module is about 1.5 Hz. Therefore, when displaying signals with frequency components of less than about 2 Hz (0.2 Hz when using a 10X attenuator probe), the best response will be obtained with the AC-DC-GND switch in the DC position.

    When looking at ac signals of very small amplitude (less than about 10 millivolts), you may wish to use the AC STABILIZED switch to eliminate dc drift in the oscilloscope trace. Placing this switch in the ON position introduces ac coupling into the amplifier whenever the VOLTS/DIV. switch is in one of its five most sensitive positions (1 mVOLTS through 20 mVOLTS). This prevents small dc drift conditions in the Input Amplifier of the module from causing trace shift on the screen. When the VOLTS/DIV. switch is at 1 mVOLTS and the AC STABILIZED switch is ON, the lower bandpass limit (3-db point) of the module is about 10 Hz.

    Note that the small neon lamp to the left of the AC STABILIZED switch lights when either AC-DC-GND switch is in the DC position while the AC STABILIZED switch is ON. This is to warn the operator that the amplifier is ac coupled when the VOLTS/DIV. switch is in one of its five most sensitive positions, even though the AC-DC-GND switch is in the DC position. (The light can be ignored if the VOLTS/DIV. switch is not in one of these positions.) If you wish to measure dc levels in one of the five most sensitive positions of the VOLTS/DIV. switch, you must set the AC STABILIZED switch to OFF.

    above excerpts from Tektronix Type 2A63 Instruction Manual
    MISC PART NUMBERS
    Knobs
    366-113Knob, Small Charcoal (POSITION)
    366-113Knob, Small Charcoal (DC BAL)
    366-038Knob, Small Red, 1/8 hole part way (VARIABLE)
    366-144Knob, Large Charcoal, 17/64 hole thru (VOLTS/DIV)
    Pots/Switches
    R436311-240200 ohm var (DC BALANCE)
    R479311-2282 x 10K 2W var (POSITION)
    R497311-2212K var. (GAIN ADJ)
    R498311-1892K var (VARIABLE)
    SW400/SW410260-450Slide Sw (AC-GND-DC)
    SW404Rotary (VOLTS/DIV)
    SW408260-447Slide Sw (AC STABILIZED)
    Tubes
    V424 6DJ8 (checked)
    V484 6CB6
    V494 6CB6
    V503 6CB6