P6230
The Tektronix P6230 is a passive ×10 (450:50 Ω) probe with 1.5 GHz bandwidth and DC offset capability, intended to minimize probe-loading effect when used on logic circuits.
It can be powered from 7000 series mainframes having LEMO S-series connectors for probe power, or compatible units such as the 1101.
The P6230 is sometimes described as a FET probe or an active probe, however, as the circuit diagram clearly shows, this is not the case. The input signal runs through a 400 Ω resistor and a 1 μF capacitor, terminated in 50 Ω internally (switchable) or externally. The active circuit in the P6230, a standard NE5532 dual opamp, has the function of restoring and offsetting the input signal's low-frequency and DC components, similar to the feed-beside technique used in the 7104 scope and 7A29 amplifier.
As a modular subminature probe, it shares accessories with many other Tektronix subminature probes although the input hybrid is unique. Tip color is yellow, connector end color is blue, part number 206-0279-00. Its end to end resistance is 400 Ω.
Key Specifications
| Bandwidth | DC to ≥ 1.5 GHz |
|---|---|
| Rise time | ≤ 230 ps |
| Attenuation | 10× |
| Input Impedance | 450 Ω // 1.3 pF (1.6 pF guaranteed) |
| Signal delay | 8.7 ± 0.1 ns |
| DC Offset range | -5 V ≤ (Vsignal + <Voffset) ≤ +5 V |
| Features |
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Links
- P6230 @ barrytech.com (incorrectly described as active probe)
Manuals
- P6230 Operator's manual (PDF, 155KB)
Prices
| Year | 1985 | 1989 |
|---|---|---|
| Catalog price | $395 | $420 |
| 2015 value | $870 | $800 |
Pictures
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P6230 compensation box
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P6230 probe tip with alligator clip ground lead
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Switchable terminator
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Probe tip components
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Compensation box interior
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Compensation box interior
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P6230 circuit diagram
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P6230 input impedance graph
Measurements
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9.2 * 20 ps = 184 ps (equiv. to 1.9 GHz bandwidth)
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Effect of using the "low inductance" ground lead - rise time 400 ps, bandwidth 875 MHz
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Using the 250 mm alligator ground lead - severe pulse distortion, rise time ~3 ns (115 MHz)!
