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title=Tektronix Type 82 |
title=Tektronix Type 82 |
summary=85 MHz Dual trace amplifier |
summary=85 MHz Dual trace amplifier |
image=Tek 82 1d.JPG |  
image=Tek_82_early_front.jpg |  
caption=Type 82 front view (later style) |
caption=Type 82 front view (earlier style) |
introduced=1962 |
introduced=1962 |
discontinued=1972 |
discontinued=1972 |
Line 21: Line 21:


==Internals==
==Internals==
The front end of the Type 82 is a [[7586]] [[nuvistor]] cathode-follower, followed by bipolar diff-amps  
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  
and diode channel switching, followed by a [[distributed amplifier|distributed output amplifier]] made  
of three [[6DJ8]] tubes, with differential 93 Ω outputs.
of three [[6DJ8]] tubes, with differential 93 Ω outputs.
Line 48: Line 49:
The [[P6008]] voltage probe was designed for use with the Type 82.
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, scopes with serial numbers before 2585 should have the back termination of the final distributed amplifier output modified to the later circuit.
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==
==Pictures==
<gallery>
<gallery>
82_front.jpg|Front view, early style
Tek_82_early_front.jpg    | Front view, early style
82_left.jpg|Left view
Tek 82 1d.JPG              | Front view, later style
82_top.jpg|Top view
Tek-585-82.jpg            | Early type 82 in [[585]] mainframe
82_right.jpg|Right view
Tek-82-left.jpg            | Left side
Tek-82-right.jpg          | Right side
Tek82-input-1.jpg          | Detail of input section
Tek82-input-2.jpg          | Detail of input section
82_front.jpg               | Front view, early style
82_left.jpg               | Left view
82_top.jpg                 | Top view
82_right.jpg               | Right view
Type 82 top.jpg
Type 82 top.jpg
Type 82 rear.jpg
Type 82 rear.jpg
Type 82 leftb.jpg
Type 82 leftb.jpg  
Type 82 bottom.jpg
Type 82 bottom.jpg
Type 82 distamp bottom.jpg|Bottom of distributed amplifier
Type 82 distamp bottom.jpg | Bottom of distributed amplifier
Type 82 distamp top.jpg|Top of distributed amplifier
Type 82 distamp top.jpg   | Top of distributed amplifier
Tek 82 1d.JPG|Front view, later style
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]]
[[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