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The Tektronix 7603 is a general-purpose 100 MHz non-storage, large-screen scope that takes two 7000-series vertical plug-ins and one 7000-series horizontal plug-in.

Variants include the a rack-mount version (R7603), and the AN/USM 281C, a ruggedized 7603 without readout (was also known as 7603N Option 11S) that includes two AM-6565 (7A15AN11) single-trace amplifiers, a TD-1085 (7B53AN11) dual time base, and a clip-on front panel cover with probes and accessories.


Bandwidth 100 MHz with 7A11, 7A16, 7A17, 7A24, 7A26; 110 MHz with 7A19, 70 MHz with 7A18
Fastest calibrated sweep 5 ns/Div
CRT std. P31 phosphor, 8 × 10 divisions of 1.22 cm (Tek T7400/154-0640-00 tube); 15 kV acceleration (-3/+12); Option 8: P11 phosphor
CRT Opt. 4 P31 phosphor, 8 × 10 divisions of 1.0 cm (Tek 154-0672-00 tube); 18 kV acceleration
CRT Opt. 6 P31 phosphor, 8 × 10 divisions of 1.22 cm (Tek 154-0673-00 tube, spectrum analyzer graticule)
Vertical modes Left / Alt / Add / Chop / Right
Trigger Source Left / Vert Mode / Right
Inputs Z Axis
Outputs Camera power, Vert signal, +Gate, +Sawtooth
Line Voltage 100 / 110 / 120 / 200 / 220 / 240 V, +/- 10%, 50—440 Hz
Power Max. 170 W
Weight 13.6 kg / 30 lb (instrument only)
Operating Environment 0°C – +50°C, < 15,000 ft


Due to the long production time of the 7603 many options were available. As some options became standard (e.g. built-in fan) some numbers were assigned twice. Later models were equipped with an IEC320 mains socket, making all Ax (power cable style) options obsolete.

  • Opt.1: Without readout (= 7603N)
  • Opt.3: Extra EMI shielding
  • Opt.4/Opt.13: Maximum-brightness CRT with reduced area (8x10 cm graticule)
  • Opt.5: Fan
  • Opt.5 (later models): 400 Hz line frequency
  • Opt.6: Spectrum analyzer graticule
  • Opt.7: Without Signals Out
  • Opt.8: P11 phosphor
  • Opt.8 (later models): protective front panel cover, 7603 only
  • Opt.11S: Ruggedized variant AN/USM 281C, specified at 50 MHz
  • Opt.20: Rear GPIB socket for 7D20, removes +Sawtooth, +Gate, vertical signal outputs, R7603 only
  • Opt.76: P7 phosphor
  • Opt.77: P7 phosphor with spectrum analyzer graticule
  • Opt.78: P11 phosphor


The 7603 was made in various versions for many years, with revisions to some subassemblies like the vertical output amplifier and HV circuits. A fan is optional.

The vertical output amplifier is built around a 155-0080-00 hybrid (U450). CRT deflection plates are not distributed.

Other custom Tek ICs used include 155-0011-00 clock & chop blanking (U55), 155-0022-00 vertical channel switch (U214), 155-0022-00 trigger channel switch (U324),and the 7000 series readout system chips.


Official Modification 36005 added a ground strap to the vertical amplifier to prevent >1 GHz oscillations.

Like the other 76xx models, the 7603 has a linear supply which does not provide +5 V for lights (A9). There was an official Tek modification to add pushbutton illumination for plugins, which involves adding a regulator, but there is also a quick'n'dirty method from Rolynn Prechtl:

I've done multiple units the cheap and dirty way. No additional regulator, no pulling the LVPS to find a place to add extra components and the best part, no cost.
Look for P90 and P10 on the rear edge of the Main Interface ECB (left side as I remember).
Connect P10-1 (GND) P90-7 or 8 (GND).
Connect P10-2 (+5 V) to P90-4 (+5 V).
Two wires and you're done.
Have experienced no problems with the extra current demand from the +5V regulated supply.


  Year 1973 1976 1980 1984 1990
Mainframe only Catalog price $1,600 $1,800 $2,260 $2,865 $4,235
2019 value $9,160 $8,040 $6,970 $7,010 $8,240
Mainframe with 2 × 7A18 + 7B53 Catalog price $3,520 $3,955 $5,225 $6,880 $10,315
2019 value $20,150 $17,670 $16,120 $16,830 $20,060