3B2
The Tektronix Type 3B2 is a delaying timebase introduced in 1963 for 560-series scopes except the 560 and 565. It can trigger on signals up to 30 MHz (limited to 500 kHz when used with low frequency vertical plugins like the 3A2).
The 3B2 has a 6CW4 Nuvistor triode cathode-follower buffer amplifier at the trigger input, followed by a differential trigger amplifier made of a pair of PNP transistors, with a 2 mA tunnel diode acting as the actual trigger.
The 3B2 has a 1 MHz crystal oscillator and a counter made of discrete transistors. It generates output pulses that enable it to communicate with a digital unit such as the 6R1 or 6R1A.
The 3B2 uses a 6AL5 tube as the disconnect diode for the sweep.
Key Specifications
| Trigger Frequency | DC to 30 MHz |
|---|---|
| Sweep Speeds | 1 sec/div to 2 μs/div |
| Sweep Types | Normal and Delayed |
Pictures
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3B2 Front
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3B2 Right
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3B2 Left
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3B2 Right
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3B2 Logic Boards
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3B2 Bottom
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3B2 Top
