Difference between revisions of "P"

From TekWiki
Jump to: navigation, search
(partial rewrite, explain purpose, add history)
Line 1: Line 1:
The Tektronix Type P plug-in is a step response calibrator [[introduced in 1959]] for [[500-series scopes]].   
+
The Tektronix Type P plug-in is a calibration aid [[introduced in 1959]] for [[500-series scopes]].   
It applies a step signal to the vertical input (plug-in connector pins 1 and 3) of the scope.   
+
It applies a fast (4 nanosecond risetime) voltage step to the mainframe vertical amplifier, via plug-in connector pins 1 and 3.  It's used when adjusting the peaking coils and the delay line.   
The step is generated by a [[mercury switch]] in the Type P and it has a 4 nanosecond risetime.   
+
The Type P is designed to simulate a perfectly-adjusted Type [[K]] plug-in being driven by a Type [[107]] square-wave generator.  The idea is to calibrate a mainframe using Type P, then use this mainframe and a 107 to calibrate other plug-ins.
The Type P is designed to simulate a Type [[K]] plug-in being driven by a Type [[107]] pulse generator.   
 
In this sense, it is designed to act as a standard, not as an ideal square pulse source. 
 
Why is this preferable to calibrating the mainframe using a square pulse? 
 
Would the high-frequency components of a square pulse cause problems?
 
 
 
The Type P was the only new plug-in for [[introduced in 1959|1959]], unless you count the upgrade
 
from Type 53/54[[C]] to Type [[CA]].  It was dropped after 1963.
 
  
 
The Type P does not contain any tubes, transistors, or tunnel diodes.  
 
The Type P does not contain any tubes, transistors, or tunnel diodes.  
It does contain a [[selenium rectifiers|selenium rectifier]].  
+
It does contain a [[selenium rectifiers|selenium rectifier]] and a [[mercury switch]].  
 
The selenium rectifier in the Type P has four sections and full-wave rectifies
 
The selenium rectifier in the Type P has four sections and full-wave rectifies
 
the 6.3 VAC that is supplied by the scope mainframe on pins 13 and 14.   
 
the 6.3 VAC that is supplied by the scope mainframe on pins 13 and 14.   
Line 20: Line 13:
 
constant component in the magnetic field to bias the switch contacts to the
 
constant component in the magnetic field to bias the switch contacts to the
 
best operating point.
 
best operating point.
 +
 +
The Type P was the only new plug-in for [[introduced in 1959|1959]], unless you count the upgrade
 +
from Type 53/54[[C]] to Type [[CA]].  It was dropped after 1963, replaced by the [[TU-7]].
  
 
* [http://bama.edebris.com/manuals/tek/p/ Tektronix Type P Manual (PDF)]
 
* [http://bama.edebris.com/manuals/tek/p/ Tektronix Type P Manual (PDF)]

Revision as of 14:00, 16 May 2011

The Tektronix Type P plug-in is a calibration aid introduced in 1959 for 500-series scopes. It applies a fast (4 nanosecond risetime) voltage step to the mainframe vertical amplifier, via plug-in connector pins 1 and 3. It's used when adjusting the peaking coils and the delay line. The Type P is designed to simulate a perfectly-adjusted Type K plug-in being driven by a Type 107 square-wave generator. The idea is to calibrate a mainframe using Type P, then use this mainframe and a 107 to calibrate other plug-ins.

The Type P does not contain any tubes, transistors, or tunnel diodes. It does contain a selenium rectifier and a mercury switch. The selenium rectifier in the Type P has four sections and full-wave rectifies the 6.3 VAC that is supplied by the scope mainframe on pins 13 and 14. The 120Hz (assuming 60Hz mains) component of the full-wave rectified waveform is applied to the coil of the mercury switch to drive the opening and closing of the contacts. An adjustable fraction of the DC component of the full-wave rectified waveform is applied to the coil of the mercury switch to create a constant component in the magnetic field to bias the switch contacts to the best operating point.

The Type P was the only new plug-in for 1959, unless you count the upgrade from Type 53/54C to Type CA. It was dropped after 1963, replaced by the TU-7.