Tektronix 1A2 50MHz Dual-Trace Amplifier (1969)

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Detailed Specifications

Samples of e-Bay Prices
Tek Catalog CostLow BidHigh Bidaverage
$350 (1969)
$460 (1973-Ltd Dmd)
$510 (1974)
$9.99 12/13/02 #1923139860 billw86@hotmail.com
$24.49 (+ ship 7 lb) 11/13/06 #180047762178 forrest62 (3 bids $9.99 start) (untested)
$19.99 (+~$12 ship) 12/6/06 #320055688408 mtpockets5599 (1 bid) (untested)
$9.99 (+ 10lb ship) 2/18/07 #170080396354 rule.woman (1 bid) (w/manual - "functioning")

The 1973 Catalog recommends using the 1A1 instead of the 1A2
  • Bandwidth : DC to 50 MHz
  • Input Sensitivity : 50 mV/div to 20 V/div
  • Input Impedance : 1 MΩ, 15 pF


    The Type 1A2 Dual-Trace Plug-In Unit contains two identical fast-rise calibrated preamplifier channels. Either channel can be used independently, or electronically switched to produce dual-trace displays. In addition, both channels can be combined at the output, adding or subtracting according to the settings of the polarity switches.

    Each channel has its own input coupling, attenuator, gain, polarity and position controls which allows each display to be adjusted independently for optimum viewing.
    There are two modes of dual-trace operation: Chopped or Alternate. In the chopped mode, an internal multivibrator swithed the channels at a free-running rate of about 220 kHz. In the alternate mode, the oscilloscope time-base generator internally switches the channels at the end of each sweep during the retrace interval.

    The Type 1A2 can be used with any ot the Tektronix 530-, 540-, or 550-series Oscilloscopes. It can also be used with the 580-series Oscilloscopes in conjunciton with the Type 81 or 81A Plug-In Adapter. The Type 1A2 can also be used with other oscilloscopes and devices through the use of the Type 127, 132, or 133 Plug-In Power Supplies.
    Characteristic Performance Requirement Supplemental Information
    Deflection Factor .05 volts/cn to 20 volts/cm in 9 calibrated steps for each channel Steps in 1-2-5 sequence
    Deflection Accuracy Within ±3% of indicated deflection with VARIABLE control fully clockwise With gain correct at .05V/cm
    Variable Deflection Factor Uncalibrated deflection factor at least 2.5 times the VOLTS/CM switch indication. This permits continuous (uncalibrated) adjustment from 0.05 volts/cm to at least 50 volts/cm
    Bandwidth : (not more than 3 dB down): Type 1A2 with Tektronix oscilloscope:
    544, 546 or 547
    DC to 50 MHz
    581, 581A, 585, 585A
    DC to 50 MHz with Type 81A Plug-In AdapterDC to 33 MHz with Type 81 Plug-In Adapter
    541, 541A, 543, 543A, 545, 545A, 545B, or 555
    DC to 33 MHz
    DC to 27 MHz
    531, 531A, 533, 533A, 535 or 535A
    DC to 15 MHz
    DC to 11 MHz
    Risetime : Type 1A2 with Tektronix oscilloscope:
    544, 546 or 547
    7 ns
    581, 581A, 585, 585A
    7 ns with Type 81A Plug-In Adapter11 ns with Type 81 Plug-In Adapter
    541, 541A, 543, 543A, 545, 545A, 545B, or 555
    11 ns
    13 ns
    531, 531A, 533, 533A, 535 or 535A
    23 ns
    32 ns
    Input RC Characteristics Typically 1 MΩ parallel with approximately 15 pF
    Maximum Input Voltage 600 volts combined DC and peak AC; 600 volts peak-to-peak AC
    Input Coupling Modes AC or DC, selected by front-panel switch GND, disconnects signal and grounds amplifier input.
    AC Low-Frequency Response Typically 3 dB down at 2 Hz direct; 0.2 Hz with 10X probe
    Display Modes Channel 1 only
    Channel 2 only
    Dual-trace, alternate between channels.
    Dual-trace, chopped between channels.
    Added algebraically
    Chopped Repetition Rate 220 kHz ±20% rate to show successive 2 µS segments of each trace
    Common Mode Rejection Ratio 20:1 for common-mode signals up to 10 cm in amplitude With optimum GAIN adjustment for both channels
    Polarity Inversion Signal on either Channel 1 or 2 can be inverted
    Output Trigger Measured at TRIG OUT connector
    Output Trigger Voltage Approximately 0.5V/cm or gain or 10 VOLTS/CM at .05
    Bandwidth Low-Frequency 3 dB down is about 10 Hz when output of the amplifier is working into 1 MΩ; High-Frequency 3 dB down is amplitude dependent.
    Output Coupling AC

    excerpts from Type 1A2 Technical Manual (Department of the Army)