D: Difference between revisions

From TekWiki
Jump to navigation Jump to search
(D was replaced by 1A7 not W)
(Specs and circuitry)
Line 38: Line 38:


==Internals==
==Internals==
Early production used a pair of [[5814]] tubes at the input while late used [[12AU7]]'s.
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.


==Specifications==
{{BeginSpecs}}
[[Category:Specifications needed]] ''please add''
{{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 09:24, 14 June 2021

Template:Plugin Sidebar 2

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