3A1
The Tektronix Type 3A1 is a 10 MHz dual-trace amplifier plug-in for 560-series scopes, introduced in 1962. It is compatible with all the scopes in the 560 series, other than the 560 itself, and also with the 129 four bay enclosure and power supply.
Key Specifications
| Bandwidth | 10 MHz |
|---|---|
| Risetime | 35 ns |
| Deflection | 10 mV/div to 10 V/div, 1−2−5 sequence |
| Input impedance | 1 MΩ // 47 pF |
Internals
The input signal passes through compensated attenuators and then into a cathode-follower stage made of two 7586 Nuvistor tubes.
Channel switching in ALTERNATE mode is done using diodes. The output stage that drives the vertical deflection plates of the scope uses a pair of 8233 frame grid power pentode tubes.
Tektronix added a 260 ns delay line to the 3A1 to make the 3A6.
Pictures
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3A1 Front
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3A1 Right
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3A1 Right
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3A1 Top
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3A1 Bottom
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3A1 Input Amplifier Schematic
