P80
The Tektronix P80 is an active probe that works only with the Type 80 plug-in for the 581 and 585 oscilloscopes.
The P80 contains a 6688 (E180F) miniature RF pentode, which functions as a phase splitter providing 93 Ω differential outputs, not a simple cathode-follower.
The P80 came with five attenuator heads:
| part number | attenuation factor |
|---|---|
| 010-306 | 2x |
| 010-307 | 5x |
| 010-308 | 10x |
| 010-309 | 20x |
| 010-310 | 50x |
Key Specifications
| Rise time | 3.5 ns in combination with Type 80 |
|---|---|
| Bandwidth | DC to 100 MHz (from 25 Ω source) in combination with Type 80 |
| Deflection | 0.1 V/Div (fixed) without optional attenuators; 0.2/0.4/0.5/1/2/5/10/20/50/100/200/500/1000 V/Div with attenuators |
| Input impedance | 100 kΩ // <14 pF (including capacitive coupler, without attenuators) |
| Input voltage | max. 150 VDC in AC position; max. 600 VDC with optional capacitive coupler; max. 100 VDC when DC coupled (without optional attenuators) |
Pictures
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Vents for tube
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P80 attached to Model 80
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Amphenol 165-14 connector, plugs into Type 80
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Photo from 1959 catalog showing Type 581 mainframe, Type 80 plug-in, Type P80 probe, and attenuator heads
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Schematic
Components
Some Parts Used in the P80
| Part | Part Number(s) | Class | Description | Used in |
|---|---|---|---|---|
| 6688 | 154-0215-00 | Vacuum Tube (Pentode) | miniature high-slope VHF/UHF pentode | P80 • 3T77 • 3T77A • 4S2A • 526 • TR-4602 |