422: Difference between revisions

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caption=Tektronix 422 front |
caption=Tektronix 422 front |
introduced=1966 |
introduced=1966 |
discontinued=(?) |
discontinued=1975 |
manuals=
manuals=
* [http://w140.com/tek_422.pdf Tektronix 422 Manual (PDF)]
* [http://w140.com/tek_422.pdf Tektronix 422 Manual (PDF)]
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* [http://w140.com/tek_422_product_reference_book.pdf Tektronix 422 Product Reference Book (PDF)]
* [http://w140.com/tek_422_product_reference_book.pdf Tektronix 422 Product Reference Book (PDF)]
}}
}}
The '''Tektronix Type 422''' is a 15 MHz portable dual-trace oscilloscope.  It was available with
The '''Tektronix Type 422''' is a 15 MHz portable dual-trace oscilloscope introduced in 1966.   
an optional battery back for operation without mains power.  Early versions use an
It was available withan optional battery back for operation without mains power.   
[[8056]] Nuvistor tube for the front-end cathode follower.  Later versions use a FET front
end.  The 422 uses [[tunnel diodes]] for triggering.  The post-deflection acceleration voltage
is 4900 Volts.


The trigger circuit in the 422 has a trigger amplifier driving a [[1N3719]] tunnel diode, D375, which
==Specifications==
[[Category:Specifications needed]]  ''please add''
 
The post-deflection acceleration voltage is 4900 V.
 
==Internals==
Early versions use an [[8056]] Nuvistor tube for the front-end cathode follower.  Later versions use a FET front
end.  The 8056 Nuvistor used in the input amplifier of the 422 can be replaced by a [[MPF102]] JFET.
 
The trigger circuit in the 422 has a trigger amplifier driving a [[1N3719]] [[tunnel diode]], D375, which
acts as a Schmitt trigger.  The trigger amplifier has a nonlinear deadband diode circuit in the
acts as a Schmitt trigger.  The trigger amplifier has a nonlinear deadband diode circuit in the
negative feedback path.  What results is high gain for small signals (little or no negative
negative feedback path.  What results is high gain for small signals (little or no negative
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D405, and the current pulse switches D405 to the high-voltage state, which starts a sweep.  
D405, and the current pulse switches D405 to the high-voltage state, which starts a sweep.  


The 8056 Nuvistor used in the input amplifier of the 422 can be replaced by a [[MPF102]] JFET.
==Links==
 
==Specifications==


==Pictures==
==Pictures==


<gallery>
<gallery>
Image:Tek 422 front.jpg
File:Tek 422 front.jpg
Image:Tek 422 side.jpg
File:Tek 422 side.jpg
Image:Tek 422 trigger.png|Trigger circuit
File:Tek 422 trigger.png|Trigger circuit
Image:Tek 422 sweep.png|Sweep circuit
File:Tek 422 sweep.png|Sweep circuit
Image:Tek 422 vertamp.png|Vertical amplifier circuit
File:Tek 422 vertamp.png|Vertical amplifier circuit
Image:Tek 422 inputamp.png|Input amplifier circuit
File:Tek 422 inputamp.png|Input amplifier circuit
Image:Tek 422 horizamp.png|Horizontal amplifier circuit
File:Tek 422 horizamp.png|Horizontal amplifier circuit
Image:Tek 422 crt.png|CRT circuit
File:Tek 422 crt.png|CRT circuit
File:422 mpf102 cal.jpg
File:422 mpf102 cal.jpg
Image:Tek 422 front part rear.jpg
File:Tek 422 front part rear.jpg
Image:Tek 422 left int.jpg
File:Tek 422 left int.jpg
Image:Tek 422 ps.jpg
File:Tek 422 ps.jpg
Image:Tek 422 right int.jpg
File:Tek 422 right int.jpg
Image:Tek 422 top.jpg
File:Tek 422 top.jpg
Image:Tek 422 trig int.jpg
File:Tek 422 trig int.jpg
Image:Tek 422 vert amp.jpg
File:Tek 422 vert amp.jpg
Image:Tek 422 vert amp2.jpg
File:Tek 422 vert amp2.jpg
Image:Tek 422 vert input amps.jpg
File:Tek 422 vert input amps.jpg
Image:Tek-422 lvps2.png|ac-dc power supply
File:Tek-422 lvps2.png|ac-dc power supply
Image:Tek 422 acps.png|ac power supply
File:Tek 422 acps.png|ac power supply
File:422 8056 mpf102.jpg|[[MPF102]] replacing [[8056]]
File:422 8056 mpf102.jpg|[[MPF102]] replacing [[8056]]
File:Wellenkino 422.jpg
File:Wellenkino 422.jpg

Revision as of 09:35, 29 September 2014

{{{manufacturer}}} 
15 MHz portable dual-trace scope
Tektronix 422 front

Produced from 1966 to 1975

Manuals
Manuals – Specifications – Links – Pictures

The Tektronix Type 422 is a 15 MHz portable dual-trace oscilloscope introduced in 1966. It was available withan optional battery back for operation without mains power.

Specifications

please add

The post-deflection acceleration voltage is 4900 V.

Internals

Early versions use an 8056 Nuvistor tube for the front-end cathode follower. Later versions use a FET front end. The 8056 Nuvistor used in the input amplifier of the 422 can be replaced by a MPF102 JFET.

The trigger circuit in the 422 has a trigger amplifier driving a 1N3719 tunnel diode, D375, which acts as a Schmitt trigger. The trigger amplifier has a nonlinear deadband diode circuit in the negative feedback path. What results is high gain for small signals (little or no negative feedback) and low gain for large signals (strong negative feedback). Thus, the signal at the base of Q364 has a limited swing over a wide range of input amplitudes. The collector current of Q364 varies between 0 and 9 mA. Depending on the position of the trigger slope control, higher collector current in Q364 either switches D375 from the low-voltage state to the high-voltage state or from the high-voltage state to the low-voltage state. When D375 transitions from the low-voltage state to the high-voltage state, it produces a current pulse in the primary of transformer T401, which produces a current pulse in the secondary of T401. The secondary of T401 feeds another tunnel diode, D405, and the current pulse switches D405 to the high-voltage state, which starts a sweep.

Links

Pictures

  • Trigger circuit

    Trigger circuit

  • Sweep circuit

    Sweep circuit

  • Vertical amplifier circuit

    Vertical amplifier circuit

  • Input amplifier circuit

    Input amplifier circuit

  • Horizontal amplifier circuit

    Horizontal amplifier circuit

  • CRT circuit

    CRT circuit

  • ac-dc power supply

    ac-dc power supply

  • ac power supply

    ac power supply

  • MPF102 replacing 8056

    MPF102 replacing 8056

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