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.

Tektronix 1502

Time Domain Reflectometer

Produced from 1975 to (?)

Manuals

1502

1502B

Tektronix 1502B Service Manual

1502C

Tektronix 1502C Service Manual (PDF)

Other

Tektronix Chart Recorder User/Service Manual (PDF)

Watertight Sealing Procedures for 1502/1503 TDRs (PDF, needs OCR)
Guide to Optimizing Falltime and Aberrations in the 1502 (PDF, needs OCR)

Note that the manuals for the 1502B and 1503C are still available from Tektronix.

(All manuals in PDF format unless noted otherwise)

Manuals – Specifications – Links – Pictures

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 first version 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/C) 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

Replacement

MOHR Test and Measurement manufactures a direct replacement to the 1502B and 1502C using an updated version of the same pulser/sampler. Any procedures or recorded waveforms are repeatable using the MOHR TDR.CT100B TDR Cable Analyzer.