View source for 7503

{{Oscilloscope Sidebar 
|manufacturer=Tektronix 
|series=7000-series scopes 
|model=7503
|image=Tektronix 7503 front in operation.jpg
|caption=Tektronix 7503, 2×[[7A12]], [[7B53A]]
|introduced=1970 
|discontinued=1972 
|summary=90 MHz non-storage mainframe
|designers=Phil Crosby;Hans Springer
|manuals=
* [[Media:070-1039-00.pdf|7503 Instruction Manual]] (schematics, OCR)
}}
The '''Tektronix 7503''' is a 90 MHz 7000-series mainframe with three module bays, [[introduced in 1970]].  It was effectively replaced by the larger-screen [[7603]] in 1972.

The 7503 project was managed by [[Phil Crosby]], and was supposed to be a [[7504]] but with one fewer plug-in. 
The 7503 was Tek's first scope to use a [[harmonica connector]] for inter-board wiring.
Prior to this, inter-board wiring had either mainly been point-to-point soldered.
Other approaches were taken on certain instruments, for example the [[7704]], in which pins sticking out of the chassis mate with holes in the boards that receive the pins and make electrical contact. 

Unlike later three-slot (7xx3) mainframes, the 7503 does supply the +5 V lamp rail, which helps with the contemporary [[7A12]] plug-in.
It also features the [[7000-series remote control connector]] at the rear of the unit.

{{BeginSpecs}}
{{Spec | Bandwidth                | 90 MHz with [[7A11]], [[7A16]] (and faster plug-ins); 75 MHz with [[7A12]], [[7A13]], [[7A14]] }}
{{Spec | Fastest calibrated sweep | 5 ns/Div }}
{{Spec | CRT                      | [[T7500|T7500 (154-0608-xx)]], 18 kV total acceleration (+15/−2.96) }}
{{Spec | Calibrator               | 4 mV to 40 V in five decade steps, 40 mA, 1 kHz ±0.5% }}
{{Spec | Outputs                  | Side panel: Vert signal, +Gate, +Sawtooth; At CRT: Camera power }}
{{Spec | Power                    | 90−110 V / 104−126 V / 112−136 V / 180−220 V / 208−252 V / 224−272 V, 50−440 Hz; max. 258 W  }}
{{Spec | Weight                   | 21.3 kg / 47 lb  (instrument only) }}
{{Spec | Rear connectors | 
* High speed Z Axis input (BNC connector, 60 V<sub>p-p</sub>, 75 MHz)
* High sensitivity Z Axis input (BNC connector, 2 V<sub>p-p</sub>, 10 MHz) 
* Two [[LEMO S-series connector]]s for [[probe power]]
* [[Amphenol 165 series connectors|Amphenol 165-16 connector]] (J1075) for [[7503, 7504, 7904 remote control connector|remote control]] (single sweep ready/reset signals)
}}
{{EndSpecs}}