1A1

Template:Plugin Sidebar 2 The Tektronix Type 1A1 plug-in for the 500-series scopes has two channels and a -3 dB point of 50 MHz at 50 mV/Div, 28 MHz at 5 mV/Div, and 2 Hz to 15 MHz at 500 μV/Div when channels 1 and 2 are cascaded.

There were three distinct versions of 1A1.

• The first version, from 1964 to 1966, has a Nuvistor front-end, and rotary input switches that were concentric with the BNC jacks. The knobs to invert the input channels are concentric with the the vertical position knobs.
• The second version, from 1966 to ??? has fluted round V/cm knobs, and lever switches. The channel inversion control is an organ-style pull-push knob.
• The third model, from ??? until the end has four-sided V/cm knobs and a FET front-end.

Type 1A1 uses the "ALT SWEEP SLAVE PULSE" signal that is sent by scopes on pin 7 of the plug-in connector. In a Type 547 mainframe, this signal allows channel 1 to be displayed using the "A" timebase and channel 2 using the "B" timebase. This is useful, for example, to view the IF and AF of a radio receiver at the same time. Even after the front-end transitioned from Nuvistors to FETs, the output amplifier continued to use Nuvistors.

Type 1A1 has an External Trigger output for mainframes prior to the 547 that don't support plug-in triggering.

Types 1A1 and 1A2 were introduced together in 1964, the former for high-end use, the latter as an upgrade/replacement for Type CA. Both remained available until the 500-series scope line was discontinued.

The 1A1 is not a perfect superset of the 1A2; it supplies external trigger from channel 1 only.

The 1A1 may have evolved from the Type J, which never went into production.

Tektronix' German distributor, Rohde & Schwarz, apparently manufactured a version of the 1A1 in Germany (see Links).

Specifications

please add

Links

• 1A1 @ amplifier.cd (pictures of a German-produced 1A1)

Pictures

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  Early 1A1

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  left: Nuvistor right: FET

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  left: Nuvistor right: FET

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  left: Nuvistor right: FET

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  Early 1A1 front end

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  Late 1A1 Output Amp

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  Early 1A1 Left View

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  Latest version of 1A1

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  556 with second version 1A1 in left bay and first version 1A1 in right bay.

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  Black 1A1