1502
The Tektronix 1502 is a series of Time Domain Reflectometers which replaced the 1501 in 1975. The 1502 is for high resolution, sister model 1503 for long range.
They are commonly used to test coaxial cables, although they have many other uses. The US military was a major purchaser, therefore most of the first series (the 1502, no letter) will be found surplus with some sort of US military property ID tag and an NSN sticker.
Hans Geerling did most of the circuit design on the 1502.
Key Specifications
- please add
Internals and version differences
The 1502 used a CRT and is an almost completely analog design except for some discrete digital logic used to pre-fire and fire the tunnel diode pulser. The later models (1502B, 1502C) used a liquid-crystal display and a Z80 microprocessor.
The other major difference between versions is the line charging method. The 1502 uses a fast (36 ps) tunnel diode pulser, the later models used a half sine wave to charge the line. The TD pulser, with its Dirac delta edge, gives much better short range sensitivity, although it is much easier to destroy.
Repair issues
→ see 1502/Repairs
Links
Documents Referencing 1502
| Document | Class | Title | Authors | Year | Links |
|---|---|---|---|---|---|
| Tekscope 1975 V7 N2.pdf | Article | Two Weatherproof TDR Cable Testers for Field Use | Ivan Ivanov | 1975 | 1502 • 1503 |
| Tekscope 1975 V7 N3.pdf | Article | New Products | 1975 | 5444 • 1502 • 1503 • 455 • E4010 • E4010-1 • 4923 • 2701 • 2703 • J6523 • WP1205 | |
| TekWeek (partial) October 10, 1975.pdf | Article | Spectrum analyzers require high technology | Thor Hallen • Dave Friedley | 1975 | Spectrum Analyzers • Pentrix • 7L5 • 5L4 • 7L12 • 7L13 • 1401 • 491 • 1405 • 1502 • 1503 |
Prices
1979: $3,750 (~$16,200 in 2024 dollars)
According to an internal memo, in 1979 annual sales were estimated at 543 units.
Pictures
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Top boards of the 1502
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Underside of 1502 with stripline sampler and pulser exposed
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Sampling gate near the BNC end of stripline
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Pulser end of the stripline
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Pulser TD removed from stripline
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Pulser TD curve traced with a 576
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HV board top view
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HV board bottom view
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Tek 1502 with printer
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Tek 1502 Metric Version (Option 5)
Components
Some Parts Used in the 1502
| Part | Part Number(s) | Class | Description | Used in |
|---|---|---|---|---|
| 152-0335-01 | 152-0335-01 | Discrete component | 150 ps step recovery diode | 1502 • S-2 • S-4 • S-6 |
| 154-0667-00 | 154-0667-00 • 154-0667-01 • 154-0667-02 • 154-0667-03 | CRT | CRT | 1502 • 1503 • 305 • 326 |
| 2N3958 | 151-1054-00 • 151-1054-01 • 151-1054-02 | Discrete component | dual n-channel JFET | FG503 • MR501 • M3 • PG505 • SC501 • SC502 • SC503 • SG502 • 1450 • 1501 • 1502 • 1503 • 221 • 5A23N • 5CT1N • 577 • 603 • 603A • 604 • 604A • 605 • 606 • 606A • 606B • 607 • 607A • 620 • 624 • 7CT1N • 7D15 • 7D20 • 851 |
| SMTD995 | 152-0140-01 | Discrete component | 10 mA, 8 pF tunnel diode | 1S1 • 1S2 • 1502 • 21A • 22A • 3T5 • 3T6 • 475 • 475A • 475M • 544 • R544 • 546 • RM546 • 547 • RM547 • 556 • R556 • 581A • 585A • RM585 • 7B52 • 7B53N • 7B70 • 7B71 • 7D10 • 7D11 • 7T11 • 7T11A • R7912 • S-51 • S-52 • TU-5 • 067-0572-00 • 067-0572-01 • 067-0681-00 |