D: Difference between revisions
Vintage dave (talk | contribs) (D was replaced by 1A7 not W) |
Vintage dave (talk | contribs) (Specs and circuitry) |
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==Internals== | ==Internals== | ||
Instruments below serial number 3462 used a pair of [[5814]] tubes at the input; later production used [[12AU7]]'s. | |||
These two tube types have different heater currents, and because the heaters are | These two tube types have different heater currents, and because the heaters are | ||
series-wired, you cannot switch from one type to the other without circuit modification. | series-wired, you cannot switch from one type to the other without circuit modification. | ||
== | {{BeginSpecs}} | ||
{{Spec | Deflection | 1 mV/Div to 50 V/Div in 1–2–5-10-20-50 sequence and 1-10-100-1000 sequence }} | |||
{{Spec | Input impedance | 1 MΩ // 47 pF (either input) }} | |||
{{Spec | Bandwidth | 2 MHz with MV/CM MULTIPLIER set to 50; 300kHz with MV/CM MULTIPLIER set to 1 }} | |||
{{Spec | CMRR | 10000:1 with MILLIVOLTS/CM set to 1, 1000:1 otherwise }} | |||
{{Spec | Signal ranges | }} | |||
{| class="wikitable" border=1 style="margin-left: 8em;" | | |||
!Range | |||
! Common mode dynamic range* | |||
|- | |||
| MILLIVOLTS/CM = 1 || ±2.5 V | |||
|- | |||
| MILLIVOLTS/CM = 10 || ±25 V | |||
|- | |||
| MILLIVOLTS/CM = 100 || ±250 V | |||
|- | |||
| MILLIVOLTS/CM = 1000 || ±500 V | |||
|- | |||
|} | |||
* In practice, Type D behaves well up to about +/-15V if the CM signal is either a brief excursion or a constant. If the CM varies slowly, DC shift in the input tubes will degrade CMRR. | |||
{{EndSpecs}} | |||
==Pictures== | ==Pictures== | ||
Revision as of 08:24, 14 June 2021
The Tektronix Type D is a differential amplifier plug-in for 500-series scopes.
Type D was the most sensitive plug-in of the original four. The bandwidth depends on the gain, ranging from 2 MHz at 50 mV/div to 300 kHz at 1 mV/div. There are two axes of sensitivity setting: a decade attenuator in front of a gain switch. This scheme would be reprised in Type W.
It displays the difference between two input signals, with a common-mode rejection ratio of 10,000. It has six tubes, on a shock-mounted subchassis to avoid microphonics.
Along with Types A, B, and C, Type D was introduced with the 531 and 535 in 1954.
At the time it was called Type 53D. It was briefly renamed 53D/54D in 1955 with the introduction of the 541 and 545. This quickly changed to 53/54D, and finally shortened to just "D" in 1959 with the introduction of the 5xxA scopes. Its final year in the catalog was 1968; it had been superseded by Type 1A7 and 1A6.
K, L, and T are tied for longest production life, at 16 years. B, D, and G are next at 15 years.
Lavoie Laboratories produced an unauthorized clone, the Lavoie LA-265-D.
Internals
Instruments below serial number 3462 used a pair of 5814 tubes at the input; later production used 12AU7's. These two tube types have different heater currents, and because the heaters are series-wired, you cannot switch from one type to the other without circuit modification.
Key Specifications
| Deflection | 1 mV/Div to 50 V/Div in 1–2–5-10-20-50 sequence and 1-10-100-1000 sequence |
|---|---|
| Input impedance | 1 MΩ // 47 pF (either input) |
| Bandwidth | 2 MHz with MV/CM MULTIPLIER set to 50; 300kHz with MV/CM MULTIPLIER set to 1 |
| CMRR | 10000:1 with MILLIVOLTS/CM set to 1, 1000:1 otherwise |
| Signal ranges |
| Range | Common mode dynamic range* |
|---|---|
| MILLIVOLTS/CM = 1 | ±2.5 V |
| MILLIVOLTS/CM = 10 | ±25 V |
| MILLIVOLTS/CM = 100 | ±250 V |
| MILLIVOLTS/CM = 1000 | ±500 V |
- In practice, Type D behaves well up to about +/-15V if the CM signal is either a brief excursion or a constant. If the CM varies slowly, DC shift in the input tubes will degrade CMRR.
Pictures
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Front
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Chassis
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Rubber support for elimination of microphonics
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Chassis bottom
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Early Schematic
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Late Schematic
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Late Attenuators
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Front View (vertical position knob not original)
