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** [[Media:070-4286-00.pdf|070-4286-00 Volume 1]] (OCR)
** [[Media:070-4286-00.pdf|070-4286-00 Volume 1]] (OCR)
** [[Media:070-4654-00.pdf|070-4654-00 Volume 2, Signature Analysis Tables]] (OCR)
** [[Media:070-4654-00.pdf|070-4654-00 Volume 2, Signature Analysis Tables]] (OCR)
<small>
{{ROM Images}}
'''ROM images'''
* [[Media:160-1959-00.bin|160-1959-00.bin A8U145]]
* [[Media:160-1960-00.bin|160-1960-00.bin A8U245]]
* [[Media:160-1961-00.bin|160-1961-00.bin A8U340]]
</small>
}}
}}
The '''Tektronix 7A42''' is a four-channel 350 MHz plug-in for [[7000-series scopes]].   
The '''Tektronix 7A42''' is a four-channel 350 MHz plug-in for [[7000-series scopes]].  It is a double-wide plug-in, designed by [[Kirk Wimmer]].
It was designed by [[Kirk Wimmer]].
It is a double-wide plug-in, with signal outputs and mainframe readout only using the left slot, allowing the it to be installed to the right of another plug-in in a four-bay mainframe.


The 7A42 was specifically designed for logic signals (TTL, ECL, CMOS) and supports triggering based on Boolean conditions of the four inputs.  The signal path and display is analog, however.
'''Vertical:'''
A fifth trace, "Trigger View", displays the trigger function output or external clock input.  
:The 7A42 was specifically designed for logic signals (TTL, ECL, CMOS). It is not a Logic Analyzer however – the signal path and display is analog.
:The input V/div setting can only be seen in the mainframe's readout, and adapts automatically when a [[BNC connector with readout ring|pin-coded ×10 probe]] is attached. (×100 probes are not supported and are incorrectly recognized as ×10.)
:A fifth trace, "Trigger View", displays the trigger function output or external clock input.  


There are two sets of conditions, A and B, that can be individually selected or paired in an "A then B" mode called ''nested triggering'', where the occurrence of condition A arms the trigger and condition B causes the trigger to be generated.
'''Triggering:'''  
The trigger can be qualified by an external clock.  A trigger filter control, variable from 0-300 ns, allows events shorter than the selected length to be suppressed.  A TTL-level "reset" input will inhibit the trigger if active.
:The 7A42 supports triggering based on Boolean conditions of the four inputs.  
:The trigger can be qualified by an external clock.  A trigger filter control, variable from 0-300 ns, allows events shorter than the selected length to be suppressed.  A TTL-level "reset" input will inhibit the trigger when active.


Selected by an internal jumper, either the trigger signal, or the "A then B" interval, is available on a front-panel trigger output. This can e.g. be routed to a counter for time measurement or event counting.  
:There are two sets of trigger conditions, A and B, that can be individually selected or paired in an "A then B" mode called ''nested triggering'', where the occurrence of condition A arms the trigger and condition B causes the trigger to be generated.
:The "A then B" interval gate signal can be routed to a counter for time measurement or event counting.


The input V/Div setting can only be seen in the mainframe's readout. 
:Selected by an internal jumper, the front-panel trigger output can be configured for either the trigger signal, or the "A then B" interval
There is a jumper to allow the readout to work in a [[7854]] mainframe.
The trigger level is set digitally and shown on a 7-segment display.


Tektronix recommended the [[P6131]], 300 MHz, 10 MΩ ×10 probe, and the [[P6230]], 1.5 GHz, 450/50 Ω ×10, variable-offset probe for ECL circuits.
:The trigger level is set digitally for each channel, and shown on a 7-segment display.  The trigger level display can also be used as a DVM to measure the offset voltage to which which an attached [[P6230]] probe is set.


The [[067-1155-99]] calibration fixture is specific to the 7A42.
'''Mainframe Interface:'''
:Signal/Trigger outputs and mainframe readout use the left slot, allowing the 7A42 to be installed in the two center bays in a four-bay mainframe, together with another vertical plug-in in the left vertical bay.
:The right slot additionally provides the "A then B" interval gate on the trigger lines. 
 
:There is a jumper to allow the readout to work in a [[7854]] mainframe.
 
'''Probes:'''
:Tektronix recommended the [[P6131]], 300 MHz, 10 MΩ ×10 probe, and the [[P6230]], 1.5 GHz, 450/50 Ω ×10, variable-offset probe for ECL circuits.


{{BeginSpecs}}
{{BeginSpecs}}
{{Spec | Bandwidth | 350 MHz in [[7104]], 300 MHz in [[7904]] }}
{{Spec | Bandwidth | 350 MHz in [[7104]], 300 MHz in [[7904]] }}
{{Spec | Deflection |
{{Spec | Deflection |
* 0.1 / 0.2 / 0.5 V/Div (TTL mode)
* TTL mode: 0.1, 0.2 or 0.5 V/div ; 1, 2 or 5 V/div with ×10 probe
* 20 / 50 / 100 mV/Div (ECL mode)
* ECL mode: 20, 50 or 100 mV/div ; 0.2, 0.5 or 1 V/div with ×10 probe  
* each direct or through 10:1 probe
* always DC coupled
* always DC coupled }}
}}
{{Spec | Input impedance | 1 MΩ // 15 pF or 50 Ω}}
{{Spec | Input impedance | 1 MΩ // 15 pF or 50 Ω }}
{{Spec | Max. input voltage |
{{Spec | Max. input voltage |
* at 1 MΩ: 25 V (DC+peak AC) below 36 MHz, down to 3 V<sub>AC</sub> at 300 MHz
* at 1 MΩ: 25 V (DC+peak AC) below 36 MHz, down to 3 V<sub>AC</sub> at 300 MHz
* at 50 Ω: 5 V<sub>RMS</sub> during any 1 ms interval}}
* at 50 Ω: 5 V<sub>RMS</sub> during any 1 ms interval}}
{{Spec | Trigger level |
{{Spec | Trigger level |
* −1.27 to +1.28 V (TTL mode) in 10 mV steps
* TTL Mode ×1: −1.27 to +1.28 V in 10 mV steps (Preset: 0.14 V)
* −254 mV to +256 mV (ECL mode) in 2 mV steps (or ×10)}}
* TTL Mode ×10: −12.7 to +12.8 V in 100 mV steps (Preset: 1.4 V)
{{Spec | Hysteresis | 40 mV (TTL), 8 mV (ECL) (or ×10)}}
* ECL Mode ×1: −0.254 V to +0.256 V in 2 mV steps (Preset: –0.13 V)
* ECL Mode ×10: −2.54 V to +2.56 V in 2 mV steps (Preset: –1.3 V)
}}
{{Spec | Trigger Hysteresis | 40/400 mV (TTL), 8/80 mV (ECL) }}
{{Spec | Features |
{{Spec | Features |
* NiCd battery to preserve front-panel control status}}
* NiCd battery to preserve front-panel control status}}
Line 62: Line 67:


==Links==
==Links==
The [[067-1155-99]] calibration fixture is specific to the 7A42.
{{Documents|Link=7A42}}
{{Documents|Link=7A42}}
{{PatentLinks|7A42}}
{{PatentLinks|7A42}}
Line 71: Line 77:


==Internals==
==Internals==
The 7A42's functions are controlled by an [[Intel 8085]]A microprocessor, with code in three 2764 EPROMs (a fourth ROM socket is unused).  The front-panel pushbuttons are handled by an Intel 8279 keyboard controller.
The 7A42's functions are controlled by an [[Intel 8085]]A microprocessor, with code in three 2764 EPROMs (a fourth ROM socket is unused).  The front-panel pushbuttons are handled by an [[Intel 8279]] keyboard controller.


Each of the four [[119-1517-00]] input attenuator modules contains five [[148-0145-00|148-0145-00 miniature bi-stable relay actuators]].  These have four long pins plugging in to the base board, driving two solenoids that move a yoke which is held in the last active position by a permanent magnet.  The yoke moves a pair of contact springs that directly short corresponding pads on the thick-film ceramic substrate. The relay coils are wired in a 4×5 matrix.
Each of the four [[119-1517-00]] input attenuator modules contains five [[148-0145-00|148-0145-00 miniature bi-stable relay actuators]].  These have four long pins plugging in to the base board, driving two solenoids that move a yoke which is held in the last active position by a permanent magnet.  The yoke moves a pair of contact springs that directly short corresponding pads on the thick-film ceramic substrate. The relay coils are wired in a 4×5 matrix.


The 7A42 contains its own switch-mode PSU, based on an SG3524 controller, that generates +5 V, −2 V and −5 V from the mainframe's ±50 V rails.
The 7A42 contains its own switch-mode PSU, based on an [[SG3524]] controller, that generates +5 V, −2 V and −5 V from the mainframe's ±50 V rails.


There is a [[7A42/Repairs|NiCd backup battery]] that allows the unit to retain its last configuration.  
There is a [[7A42/Repairs|NiCd backup battery]] that allows the unit to retain its last configuration.  

Latest revision as of 03:40, 5 July 2024

Tektronix 7A42
350 MHz four-channel logic triggered amplifier
7A42 front view

Compatible with 7000-series scopes

Produced from 1984 to 1990

Manuals
ROM Images
File Pos. Checksum
160-1959-00 A8U145 2e9a8923
160-1960-00 A8U245 c31d60f0
160-1961-00 A8U340 1e8c4ba6
(All manuals in PDF format unless noted otherwise)
Manuals – Specifications – Links – Pictures

The Tektronix 7A42 is a four-channel 350 MHz plug-in for 7000-series scopes. It is a double-wide plug-in, designed by Kirk Wimmer.

Vertical:

The 7A42 was specifically designed for logic signals (TTL, ECL, CMOS). It is not a Logic Analyzer however – the signal path and display is analog.
The input V/div setting can only be seen in the mainframe's readout, and adapts automatically when a pin-coded ×10 probe is attached. (×100 probes are not supported and are incorrectly recognized as ×10.)
A fifth trace, "Trigger View", displays the trigger function output or external clock input.

Triggering:

The 7A42 supports triggering based on Boolean conditions of the four inputs.
The trigger can be qualified by an external clock. A trigger filter control, variable from 0-300 ns, allows events shorter than the selected length to be suppressed. A TTL-level "reset" input will inhibit the trigger when active.
There are two sets of trigger conditions, A and B, that can be individually selected or paired in an "A then B" mode called nested triggering, where the occurrence of condition A arms the trigger and condition B causes the trigger to be generated.
The "A then B" interval gate signal can be routed to a counter for time measurement or event counting.
Selected by an internal jumper, the front-panel trigger output can be configured for either the trigger signal, or the "A then B" interval
The trigger level is set digitally for each channel, and shown on a 7-segment display. The trigger level display can also be used as a DVM to measure the offset voltage to which which an attached P6230 probe is set.

Mainframe Interface:

Signal/Trigger outputs and mainframe readout use the left slot, allowing the 7A42 to be installed in the two center bays in a four-bay mainframe, together with another vertical plug-in in the left vertical bay.
The right slot additionally provides the "A then B" interval gate on the trigger lines.
There is a jumper to allow the readout to work in a 7854 mainframe.

Probes:

Tektronix recommended the P6131, 300 MHz, 10 MΩ ×10 probe, and the P6230, 1.5 GHz, 450/50 Ω ×10, variable-offset probe for ECL circuits.

Key Specifications

Bandwidth 350 MHz in 7104, 300 MHz in 7904
Deflection
  • TTL mode: 0.1, 0.2 or 0.5 V/div ; 1, 2 or 5 V/div with ×10 probe
  • ECL mode: 20, 50 or 100 mV/div ; 0.2, 0.5 or 1 V/div with ×10 probe
  • always DC coupled
Input impedance 1 MΩ // 15 pF or 50 Ω
Max. input voltage
  • at 1 MΩ: 25 V (DC+peak AC) below 36 MHz, down to 3 VAC at 300 MHz
  • at 50 Ω: 5 VRMS during any 1 ms interval
Trigger level
  • TTL Mode ×1: −1.27 to +1.28 V in 10 mV steps (Preset: 0.14 V)
  • TTL Mode ×10: −12.7 to +12.8 V in 100 mV steps (Preset: 1.4 V)
  • ECL Mode ×1: −0.254 V to +0.256 V in 2 mV steps (Preset: –0.13 V)
  • ECL Mode ×10: −2.54 V to +2.56 V in 2 mV steps (Preset: –1.3 V)
Trigger Hysteresis 40/400 mV (TTL), 8/80 mV (ECL)
Features
  • NiCd battery to preserve front-panel control status
Weight 2.8 kg / 6.2 lb

Links

The 067-1155-99 calibration fixture is specific to the 7A42.

Documents Referencing 7A42

Document Class Title Authors Year Links
42W-5588.pdf Application Note Advanced Triggering Techniques Roger Ensrud 1984 7A42 • 7D11 • 7D15

Patents that may apply to 7A42

Page Title Inventors Filing date Grant date Links
Patent US 3584174A Push-button switch apparatus having cam actuated switch contacts and selective illumination means Tony Sprando • Peter S Winkelmann 1969-06-09 1971-06-08 Back-lit switches • 7A11 • 7A12 • 7A13 • 7A14 • 7A16 • 7A16P • 7A22 • 7A42 • 7B42N • 7B50 • 7B51 • 7B52 • 7B53A • 7B70 • 7B71 • 7B92 • 7B92A • 7D10 • 7D11 • 7D12 • 7D114 • 7D15 • 7D20 • 7F10 • 7L5 • 7L12 • 7L13 • 7L14 • 7L18 • 7M13 • 7S11 • 7S12 • 7T11 • 067-0587-00 • 067-0587-01 • 067-0587-02 • 067-0587-10
Patent US 4513417A Automatic processor restart circuit James S. Lamb • Warren K. Wimmer 1982-11-29 1985-04-23 7A42
Patent US 4585975A High speed Boolean logic trigger oscilloscope vertical amplifier with edge sensitivity and nested trigger Warren K. Wimmer 1983-04-21 1986-04-29 7A42

See also

Internals

The 7A42's functions are controlled by an Intel 8085A microprocessor, with code in three 2764 EPROMs (a fourth ROM socket is unused). The front-panel pushbuttons are handled by an Intel 8279 keyboard controller.

Each of the four 119-1517-00 input attenuator modules contains five 148-0145-00 miniature bi-stable relay actuators. These have four long pins plugging in to the base board, driving two solenoids that move a yoke which is held in the last active position by a permanent magnet. The yoke moves a pair of contact springs that directly short corresponding pads on the thick-film ceramic substrate. The relay coils are wired in a 4×5 matrix.

The 7A42 contains its own switch-mode PSU, based on an SG3524 controller, that generates +5 V, −2 V and −5 V from the mainframe's ±50 V rails.

There is a NiCd backup battery that allows the unit to retain its last configuration.

A 555 timer implements a 15 ms "real-time clock" and watchdog reset, another drives a beeper.

An internal jumper enables partial compatibility with a 7854 mainframe in storage mode (displaying any single channel, 1+2 in ALT, or 3+4 in ALT only). There are no restrictions with the 7854 in analog mode.

Pictures

  • display - four signal traces plus trigger view

    display - four signal traces plus trigger view

  • 7A42 rear view

    7A42 rear view

  • 7A42 top view

    7A42 top view

  • Schematic cartoon: Bus

    Schematic cartoon: Bus

  • Schematic cartoon: Chirp

    Schematic cartoon: Chirp

Internal

  • amplifier board (one attenuator cover removed)

    amplifier board (one attenuator cover removed)

  • amplifier board front - attenuators, amplifiers, channel switches

    amplifier board front - attenuators, amplifiers, channel switches

  • amplifier board rear - channel switches, two 15 ns delay lines

    amplifier board rear - channel switches, two 15 ns delay lines

  • attenuator, cover removed

    attenuator, cover removed

  • attenuator cover

    attenuator cover

  • attenuator, top

    attenuator, top

  • attenuator, one relay actuator removed

    attenuator, one relay actuator removed

  • attenuator, all relay actuators removed

    attenuator, all relay actuators removed

  • attenuator, all relay actuators removed

    attenuator, all relay actuators removed

  • microprocessor board

    microprocessor board

  • memory backup battery on microprocessor board replaced with LiIon

    memory backup battery on microprocessor board replaced with LiIon

  • internal switch mode PSU for digital logic supplies

    internal switch mode PSU for digital logic supplies

Components

Some Parts Used in the 7A42

Part Part Number(s) Class Description Used in
148-0145-00 148-0145-00 Discrete component miniature bi-stable relay actuator 7A42 • 119-1517-00
155-0038-01 155-0038-00 • 155-0038-01 Monolithic integrated circuit 5-bit current source D/A converter 7A42 • 7D13 • 7D14 • 7M13 • T4005
155-0078-00 155-0078-xx • 155-0273-00 • 155-0274-00 Monolithic integrated circuit broadband amplifier 464 • 465 • 466 • 468 • 475 • 475A • 475M • 485 • 7834 • 7844 • 7854 • 7904 • R7903 • R7912 • 7912AD • 7912HB • 7104 • 7A16A • 7A16P • 7A24 • 7A26 • 7A42 • 067-0587-01 • 067-0680-00 • AM503 • PG502 • PG508 • DC510 • DC5010 • FG5010
155-0236-00 155-0236-00 Hybrid integrated circuit channel switch 2445 • 2465 • 2467 • 7A42
ICM7218 156-1621-00 • 156-1622-00 Monolithic integrated circuit 8-digit, 7-segment LED driver 7A42 • SG5010
Intel 8085A 156-1088-00 Monolithic integrated circuit 8-bit microprocessor 308 • 468 • 4025 • 7A42 • 7D02 • AFG5101 • AFG5102 • PFG5105
Intel 8279 156-1535-00 Monolithic integrated circuit keyboard controller 7A42 • AFG5101 • DM5010 • FG5010 • PFG5105
SG3524 156-0933-00 • 156-0933-01 • 156-1585-00 • 156-1585-01 Monolithic integrated circuit PWM switch-mode controller 067-1011-00 • 1502B • 1502C • 1503B • 1503C • 7A42
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