11A71: Difference between revisions

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{{Plugin Sidebar 2 |
{{Plugin Sidebar  
title=Tektronix 11A71 |
|manufacturer=Tektronix
summary=Single channel 1 GHz amplifier |
|series=11000-series scopes
image=11a71-ext.jpg |
|type=11A71  
caption=Tek 11A71 |
|summary=Single channel 1 GHz amplifier  
series=[[11000-series scopes]] |
|image=11a71-ext.jpg  
introduced=1987 |
|caption=Tek 11A71  
discontinued=(?) |
|introduced=1987  
manuals=
|discontinued=(?)  
* [http://w140.com/tek_11a71_service.pdf Tektronix 11A71 Service Manual (PDF)]
|designers=
|manuals=
* [[Media:070-6288-01.pdf|Tektronix 11A71 User Reference]]
* [[Media:070-6787-01.pdf|Tektronix 11A71 Service Manual -01]]
* [[Media:070-6787-00.pdf|Tektronix 11A71 Service Manual -00]]
* [[Media:070-7392-99.pdf|Tektronix 11A71 Extended Service Manual]]
* [[Media:Tek 11A71 schematics.pdf|Tektronix 11A71 Schematics]]
* [[Media:Tek 11A71 schematics.pdf|Tektronix 11A71 Schematics]]
* [[Media:Tektronix 11k plugin NVRAM replacement.pdf|Tektronix 11k Plug-in NVRAM Replacement]]
}}
}}
The '''Tektronix 11A71''' a single-channel 1 GHz amplifier for 11000-series scopes.   
The '''Tektronix 11A71''' a single-channel 1 GHz amplifier for 11000-series scopes.   


The 11A71 is derived from the [[7A29]].
The 11A71 is derived from the [[7A29]]. However, the 7A29 has a VARIABLE gain control while the 11A71 does not, it has only the 1−2−5 gain sequence.
However, the 7A29 has a VARIABLE gain control
 
while the 11A71 does not.
The 7A29 and 11A71 have virtually the same analog circuitry including a [[Patent US 3689752A|Gilbert multiplier]] at the front end, but in the 11A71 it is only used for automatic calibration, not for fine gain control.
The 11A71 only the 1-2-5 gain sequence.
This is feature regression, but it avoids an issue that the 7A29 has, namely that its bandwidth changes substantially with the setting of the front panel VARIABLE VOLTS/DIV control.
The 7A29 and 11A71 have the same Gilbert cell at the front end, but in the 11A71 it is only used for automatic calibration, not for fine gain control.
 
This is a feature regression, but it avoids an issue that the 7A29 has:
After calibration, there is a small imbalance in the 10 mV/div setting, about 0.05 div.
the bandwidth of the 7A29 varies depending on the setting of the VARIABLE gain.
This is a design flaw.


{{BeginSpecs}}
{{BeginSpecs}}
Line 28: Line 34:
{{Spec | Input impedance | 50 Ω via a [[Tekprobe BNC connector]] on the front on the plug-in}}
{{Spec | Input impedance | 50 Ω via a [[Tekprobe BNC connector]] on the front on the plug-in}}
{{Spec | Features |
{{Spec | Features |
*Input 5 V<sub>RMS</sub> overload protected with manual reset
* Input 5 V<sub>RMS</sub> overload protected with manual reset
}}
}}
{{EndSpecs}}
{{EndSpecs}}
==Internals==
Custom Tek chips used: [[155-0180-00]], [[155-0181-00]], [[155-0175-00]], [[155-0076-00]], ...


==Links==
==Links==
Line 46: Line 49:
11a71-amp.jpg      | Amplifier section.  Blue cable from input attenuator connects to the [[155-0180-00|155-0180-00 input protection circuit]].  Signal is differential from after the first amplifier up to the AD converter in the mainframe.
11a71-amp.jpg      | Amplifier section.  Blue cable from input attenuator connects to the [[155-0180-00|155-0180-00 input protection circuit]].  Signal is differential from after the first amplifier up to the AD converter in the mainframe.
11a71-comp.jpg      | Compensation trimmers
11a71-comp.jpg      | Compensation trimmers
11a71-detail.jpg    | Close-up of late-80s RF design  
11a71-detail.jpg    | Close-up of late-70s RF design  
11a71-digital.jpg  | Digital board, 8031 MCU
11a71-digital.jpg  | Digital board, 8031 MCU
11a71-daughter.jpg  | Digital daughter board
11a71-daughter.jpg  | Digital daughter board
Line 58: Line 61:
Tek 11a71 right internal.jpg|right internal
Tek 11a71 right internal.jpg|right internal
</gallery>
</gallery>
==Components==
{{Parts|11A71}}


[[Category:11000 series plugins]]
[[Category:11000 series plugins]]
[[Category:Tekprobe BNC]]
[[Category:Tekprobe BNC]]
[[Category:Introduced in 1987]]

Latest revision as of 03:09, 23 September 2023

Tektronix 11A71
Single channel 1 GHz amplifier
Tek 11A71

Compatible with 11000-series scopes

Produced from 1987 to (?)

Manuals
Manuals – Specifications – Links – Pictures

The Tektronix 11A71 a single-channel 1 GHz amplifier for 11000-series scopes.

The 11A71 is derived from the 7A29. However, the 7A29 has a VARIABLE gain control while the 11A71 does not, it has only the 1−2−5 gain sequence.

The 7A29 and 11A71 have virtually the same analog circuitry including a Gilbert multiplier at the front end, but in the 11A71 it is only used for automatic calibration, not for fine gain control. This is feature regression, but it avoids an issue that the 7A29 has, namely that its bandwidth changes substantially with the setting of the front panel VARIABLE VOLTS/DIV control.

After calibration, there is a small imbalance in the 10 mV/div setting, about 0.05 div. This is a design flaw.

Key Specifications

Bandwidth DC to 1 GHz
Number of Inputs 1
Rise time 350 ps in 1 GHz mainframe such as the 11402, 11402A. 11403, 11403A, DSA601A, or DSA602A
Deflection 1 mV/Div to 1 V/Div in 1−2−5 sequence
Input impedance 50 Ω via a Tekprobe BNC connector on the front on the plug-in
Features
  • Input 5 VRMS overload protected with manual reset

Links

Pictures

  • 11A71 external view

    11A71 external view

  • Block diagram

    Block diagram

  • Right side of the 11A71 plug-in (analog board)

    Right side of the 11A71 plug-in (analog board)

  • Input section. Cable loop acts as a delay line, connects to the input attenuator.

    Input section. Cable loop acts as a delay line, connects to the input attenuator.

  • Input attenuator, 50 Ω signal path. Laser-trimmed thick film resistors. AC coupling capacitor in plastic support.

    Input attenuator, 50 Ω signal path. Laser-trimmed thick film resistors. AC coupling capacitor in plastic support.

  • Amplifier section. Blue cable from input attenuator connects to the 155-0180-00 input protection circuit. Signal is differential from after the first amplifier up to the AD converter in the mainframe.

    Amplifier section. Blue cable from input attenuator connects to the 155-0180-00 input protection circuit. Signal is differential from after the first amplifier up to the AD converter in the mainframe.

  • Compensation trimmers

    Compensation trimmers

  • Close-up of late-70s RF design

    Close-up of late-70s RF design

  • Digital board, 8031 MCU

    Digital board, 8031 MCU

  • Digital daughter board

    Digital daughter board

  • Attenuator

    Attenuator

  • Kernel

    Kernel

  • Amplifier

    Amplifier

  • Interface

    Interface

  • left internal

    left internal

  • right internal

    right internal

Components

Some Parts Used in the 11A71

Part Part Number(s) Class Description Used in
155-0076-00 155-0076-00 Monolithic integrated circuit input protection and probe logic 465 • 485 • 7A29 • 7A29P • 11A52 • 11A71 • 11A72 • SCD1000
155-0175-00 155-0175-00 • 155-0175-05 Monolithic integrated circuit broadband amplifier 7904A • 7912HB • 7934 • 7104 • R7103 • 7A29 • 7A29P • 7F10 • 067-0587-02 • 067-0587-10 • 11A71 • SCD1000 • EG&G N-AM-173A
155-0180-00 155-0180-00 Hybrid integrated circuit fast input protection 7A29 • 7A29P • 7F10 • 11A71
155-0181-00 155-0181-00 Hybrid integrated circuit input amplifier 7A29 • 7A29P • 7F10 • 11A71
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