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The Tektronix Type 82 is a dual-trace plug-in for the [[580-series scopes]].   
{{Plugin Sidebar 2|
The Type 82 combined with a [[585]] or 585A provides a 4 nanosecond risetime.   
title=Tektronix Type 82 |
The front end of the Type 82 is a [[7586]] nuvistor cathode-follower,  
summary=85 MHz Dual trace amplifier |
followed by bipolar diff-amps and diode channel switching,  
image=Tek_82_early_front.jpg |
followed by a distributed output amplifier made of three [[6DJ8]] tubes,  
caption=Type 82 front view (earlier style) |
with differential 93-ohm outputs.  
introduced=1962 |
discontinued=1972 |
series=[[580-series scopes]]|
manuals=
* [http://w140.com/tek-82.pdf Tektronix Type 82 Manual (PDF)]
}}
 
The '''Tektronix Type 82''' is a dual-trace plug-in for the [[580-series scopes]].   
The Type 82 combined with a [[585]] or 585A provides a 4 nanosecond risetime (85 MHz bandwidth).   
 
{{BeginSpecs}}
{{Spec | Rise time  | 4 ns in ×1 mode, 4.3 ns in ×10 mode (in [[585]] mainframe)  }}
{{Spec | Bandwidth  | 85 MHz in ×1 mode, 80 MHz in ×10 mode (in [[585]] mainframe); 70 MHz/66 MHz, respectively, with [[P6008]] probe }}
{{Spec | Deflection | 50 V/Div to 100 mV/Div in ×1 mode, 5 V/Div to 10 mV/Div in ×10 mode (1-2-5) }}
{{EndSpecs}}
 
==Internals==
The front end of the Type 82 has three versions, depending on serial number range.
In all versions, the signal path starts with a [[7586]] [[nuvistor]] cathode-follower, followed by bipolar diff-amps  
and diode channel switching, followed by a [[distributed amplifier|distributed output amplifier]] made  
of three [[6DJ8]] tubes, with differential 93 Ω outputs.
The use of a distributed amplifier in a plug-in is unusual.   
The use of a distributed amplifier in a plug-in is unusual.   
Note that the 58x series differs from [[500-series scopes]] mainly in that  
Note that the 58x series differs from [[500-series scopes]] mainly in that the vertical  
the vertical signal interface between the plug-in and the mainframe is  
signal [[580 Series plug-in interface|interface between the plug-in and the mainframe]]
a low controlled impedance (93 ohms), as opposed to other 500-series scopes  
is a low controlled impedance (93 ohms), as opposed to other 500-series scopes  
that present a high impedance to the plug-in.
that present a high impedance to the plug-in.


* [http://w140.com/tek-82.pdf Tektronix Type 82 Manual (PDF)]
[[Stan Griffiths]] wrote:
<blockquote>
If you feed [a fast risetime] signal into an early type 82, you will
find that the top three least sensitive positions have really terrible frequency
response ... so bad, in fact, that some customers thought they were broken.
When told this was normal, these customers wondered why Tek ever included them
on the plugin. The answer was that they were still useful for low frequency
signals ... but Tek never really made it well known that these 82 attenuator
positions were lousey. I think this was fixed on the later 82's as Tek learned
how to make better attenuators. If you have an early 82 and need to look at
high frequency signals on the less sensitive ranges, the answer is to get ×100
probes and use them on the more sensitive ranges where the frequency response is
better.
</blockquote>
 
The [[P6008]] voltage probe was designed for use with the Type 82.
 
The [[585]] manual warns that for proper performance with the 82 and higher-numbered plug-ins, 585 non-A scopes with serial numbers before 2585 should have the back termination of the final distributed amplifier output modified to the later circuit (modification 040-275).


==Prices==
{| class="wikitable"
|-
! Year
! 1965
! 1969
! 1971*
|-
! Type 82
|align=right|  $650
|align=right|  $695
|align=right|  $925
|-
! 2020 value
|align=right|  $5,340
|align=right|  $4,900
|align=right|  $5,910
|}
: ''* "Limited demand" instrument
==Pictures==
<gallery>
<gallery>
Image:82_front.jpg|Front view, early style.
Tek_82_early_front.jpg    | Front view, early style
Image:82_left.jpg|Left view.
Tek 82 1d.JPG              | Front view, later style
Image:82_top.jpg|Top view.
Tek-585-82.jpg            | Early type 82 in [[585]] mainframe
Image:82_right.jpg|Right view.
Tek-82-left.jpg            | Left side
Image:Type 82 top.jpg
Tek-82-right.jpg          | Right side
Image:Type 82 rear.jpg
Tek82-input-1.jpg          | Detail of input section
Image:Type 82 leftb.jpg
Tek82-input-2.jpg          | Detail of input section
Image:Type 82 front.jpg|Front view, later style.
82_front.jpg               | Front view, early style
Image:Type 82 bottom.jpg
82_left.jpg               | Left view
Image:Type 82 distamp bottom.jpg|Bottom of distributed amplifier.
82_top.jpg                 | Top view
Image:Type 82 distamp top.jpg|Top of distributed amplifier.
82_right.jpg               | Right view
Type 82 top.jpg
Type 82 rear.jpg
Type 82 leftb.jpg  
Type 82 bottom.jpg
Type 82 distamp bottom.jpg | Bottom of distributed amplifier
Type 82 distamp top.jpg   | Top of distributed amplifier
Type 82 front.jpg
Tek 82 late input schematic.png|Input schematic for late serial numbers
Tek 82 x10 amplifiers schematic.png|x10 amplifiers schematic
Tek 82 switching and output schematic.png|Switching and output schematic
</gallery>
</gallery>
[[Category:580 series plugins]]

Revision as of 07:04, 24 May 2021

Template:Plugin Sidebar 2

The Tektronix Type 82 is a dual-trace plug-in for the 580-series scopes. The Type 82 combined with a 585 or 585A provides a 4 nanosecond risetime (85 MHz bandwidth).

Key Specifications

Rise time 4 ns in ×1 mode, 4.3 ns in ×10 mode (in 585 mainframe)
Bandwidth 85 MHz in ×1 mode, 80 MHz in ×10 mode (in 585 mainframe); 70 MHz/66 MHz, respectively, with P6008 probe
Deflection 50 V/Div to 100 mV/Div in ×1 mode, 5 V/Div to 10 mV/Div in ×10 mode (1-2-5)

Internals

The front end of the Type 82 has three versions, depending on serial number range. In all versions, the signal path starts with a 7586 nuvistor cathode-follower, followed by bipolar diff-amps and diode channel switching, followed by a distributed output amplifier made of three 6DJ8 tubes, with differential 93 Ω outputs.

The use of a distributed amplifier in a plug-in is unusual. Note that the 58x series differs from 500-series scopes mainly in that the vertical signal interface between the plug-in and the mainframe is a low controlled impedance (93 ohms), as opposed to other 500-series scopes that present a high impedance to the plug-in.

Stan Griffiths wrote:

If you feed [a fast risetime] signal into an early type 82, you will find that the top three least sensitive positions have really terrible frequency response ... so bad, in fact, that some customers thought they were broken. When told this was normal, these customers wondered why Tek ever included them on the plugin. The answer was that they were still useful for low frequency signals ... but Tek never really made it well known that these 82 attenuator positions were lousey. I think this was fixed on the later 82's as Tek learned how to make better attenuators. If you have an early 82 and need to look at high frequency signals on the less sensitive ranges, the answer is to get ×100 probes and use them on the more sensitive ranges where the frequency response is better.

The P6008 voltage probe was designed for use with the Type 82.

The 585 manual warns that for proper performance with the 82 and higher-numbered plug-ins, 585 non-A scopes with serial numbers before 2585 should have the back termination of the final distributed amplifier output modified to the later circuit (modification 040-275).

Prices

Year 1965 1969 1971*
Type 82 $650 $695 $925
2020 value $5,340 $4,900 $5,910
* "Limited demand" instrument

Pictures