502: Difference between revisions
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===Diagrams=== | ===Diagrams=== | ||
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Tek 502a block.png|502A block diagram | Tek 502a block.png | 502A block diagram | ||
Tek-502a vert.png|502A vertical amplifier | Tek-502a vert.png | 502A vertical amplifier | ||
Tek 502 crt circuit.png|502 CRT circuit ( | Tek 502 crt circuit.png | Early 502 CRT circuit, [[120-114]] transformer (secondary transformer pin numbers incorrect) | ||
Tek 502a hvps.png|502A CRT circuit | Tek 502 crt circuit 070-090.png | Later 502 CRT circuit, [[120-150]] transformer | ||
502-mountain-climber.png | Tek 502a hvps.png | 502A CRT circuit, [[120-150]] transformer | ||
502-mountain-climber.png | [[Tektronix Cartoons|Cartoon]] in schematic: Mountain Climber | |||
</gallery> | </gallery> | ||
Revision as of 05:44, 3 November 2019
The Tektronix 502 is a dual-beam oscilloscope introduced in 1958, followed by the 502A in 1963. There is also a rack-mount model, the RM502A.
Both beams have differential inputs. The horizontal deflection plates are common to both beams.
Mod 104 on a 502 provides single sweep lockout. This feature is standard on the 502A, which also has beam finder switches for each channel.
A recessed switch in the left side panel allows the upper beam amplifier to be connected to the horizontal deflection plates for single-beam X-Y operation, providing a differential X input with the same sensitivity as the Y channel. The upper beam is positioned off screen in this mode.
Key Specifications
Deflection | 100 μV/cm to 20 V/cm, 1−2−5, ±3% |
---|---|
Bandwidth | 1 MHz @ 200 mV/cm and above; 400 kHz @ 50 mV/cm, 200 kHz @ 5 mV/cm, 100 kHz @ 200 μV/cm |
CMRR | 502A: 40,000:1 @ 100 mV/cm and 1 kHz |
Input impedance | 1 MΩ // 47 pF |
Sweep | 1 μs/cm to 5 s/cm, 1−2−5, ±3%; magnifier ×2, ×5, ×10 or ×20 |
CRT | Early 502: Type T60P2/T502P2/T5020P2; Late 502, 502A: Type T5021P2; (P1, P7 or P11 were available as options) 10 vertical and 10 horizontal 1 cm divisions 3 kV acceleration |
Dimensions | 597 mm (23½") × 286 mm (11¼") × 381 mm (15") L×W×H |
Weight | 23.6 kg (52lb) |
Prices
Year | 1959 | 1961 | 1963 (A) | 1971 (A) |
---|---|---|---|---|
Catalog price | $825 | $825 | $1,050 | $1,265 |
2018 value | $7,070 | $6,890 | $8,560 | $7,790 |
Internals
There is a transistor-regulated 6.2 VDC heater supply for the tubes in the first stage differential amplifier. This heater supply uses the −150 V supply as its reference. The −150 V supply uses a 5651 voltage reference tube as its reference. There is no post-deflection acceleration. The CRT cathode voltage is −2.9 kV.
Later 502A have solid state (plus nuvistor) input stage, a 6DJ8 as the deflection amplifier, and transistors as amplifiers and emitter followers (only in the newest version).
The early 502 uses a single supply for the upper beam and lower beam CRT cathodes (HV transformer 120-114). Later models (1959+, see 070-090) and the 502A have separate supplies for the two CRT cathodes (HV transformer 120-150). This improvement allows slight differences in horizontal CRT sensitivity between the two beams to be cancelled out in step 8 of the calibration procedure.
Links
- Tektronix 502A @ amplifier.cd (many internal pictures)
Pictures
502
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502 without Mod 104, front
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502 with Mod 104 (single sweep), front
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502 front view
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502 left
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502 right
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rubber shock mount of amplifier sub-chassis
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502 bottom
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502 trace
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502 trace
502A
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502A
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502A right internal
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502A right
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502A left
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502A rear
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Solid-state input stage with two 6DJ*
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502A vertical amp sn 25,997 to 30,999
RM502A
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RM502A
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RM502A rear
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RM 502A
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RM 502A display
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RM 502A bottom
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RM 502A transformer wiring
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RM 502A top
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RM 502A vibration-isolated vertical amp
Third version 502A, serial number ≥31,000
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top side lower beam input amp and attenuator, bottom side of upper beam vert input board
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late model RM502A
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late model RM502A
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late model RM502A
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late model RM502A
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late model RM502A
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late model RM502A
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late model RM502A