S-4: Difference between revisions
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* [http://w140.com/tek_S4_1985.pdf Tektronix S-4 Manual, revised 1985 (PDF)] | * [http://w140.com/tek_S4_1985.pdf Tektronix S-4 Manual, revised 1985 (PDF)] | ||
* [http://w140.com/frye_s4_gate.pdf George Frye's Explanation of S-4 sampler in October 1968 Service Scope (PDF)] | * [http://w140.com/frye_s4_gate.pdf George Frye's Explanation of S-4 sampler in October 1968 Service Scope (PDF)] | ||
* [[Media:Tek s-4 fcp april 1969.pdf|Tektronix S-4 Factory Calibration Procedure, April 1969 (PDF, needs OCR)]] | |||
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The '''Tektronix S-4''' is a sampling head for 7000- and 3S-series samplers. | The '''Tektronix S-4''' is a sampling head for 7000- and 3S-series samplers. | ||
Revision as of 08:00, 2 June 2019
Template:Plugin Sidebar 2 The Tektronix S-4 is a sampling head for 7000- and 3S-series samplers. It was designed by George Frye and introduced in 1968. It is the fastest of the S-series plug-in samplers.
Key Specifications
| Rise time | 25 ps (observed with S-50 or S-52, 35 ps) |
|---|---|
| Bandwidth | 14.5 GHz |
| Input impedance | 50 Ω (terminated SMA connector) |
| Input range | 1 Vp-p (operating) |
| Maximum input | ±5 V max. non-destructive |
| Noise | < 5 mV |
| Features |
|
Internals
The S-4 sampling gate is based upon a traveling wave trapped-charge transmission line in which the sampling window is set by the propagation time of a pulse edge through a thick-film transmission line. This technique requires only a sharp pulse edge rather than a precise pulse width, which is harder to generate. The sampling diodes are housed in a special coaxial connector that provides a high bandwidth signal path.
To disassemble the sampler hybrid, first remove it from the sampler board as per the manual. Remove the input connector using a 7/32" wrench and remove the 20 dB attenuator with small pliers. The ceramic board is held to the housing using roll pins that can be pressed out with a 0.030" pin punch. The hybrid has six diodes, each about 0.75mm square. The cathodes are glued to the gold substrate with conductive epoxy and the anodes are wire-bonded (twice) over a gap to the next step in the strobe line. It appears that a standard beam-lead diode may fit across the gap but cleanly removing a failed diode without damaging the substrate would be quite difficult.
Links
- S-4 page @ amplifier.cd
- James R. Andrews, Comparison of Ultra-Fast Rise Sampling Oscilloscopes. Picosecond Pulse Labs App Note AN-2a, 1989
