Difference between revisions of "181"

From TekWiki
Jump to navigation Jump to search
Line 1: Line 1:
[[File:181_PC_ISO.jpg|thumb|350px|right|181, early version]]
+
{{Instrument Sidebar
The '''Tektronix Type 181''' is a time mark generator [[introduced in 1955]].  There is a benchtop version,
+
|manufacturer=Tektronix
the 181, and a rackmount version, the RM181. MOD 110 substitutes a oven-stabilized
+
|model=181
1 MHz crystal oscillator (OCXO), the CO181 (Tek part number [[158-007]]),  
+
|class=Pulse Generator
thereby achieving 2 parts per million
+
|series=
frequency stability in a 24 hour period, the same stability as the [[180A]].
+
|summary=Time mark generator
 +
|image=181_PC_ISO.jpg
 +
|caption=181, early version
 +
|introduced=1955
 +
|discontinued=(?)
 +
|designers=
 +
|manuals=
 +
* [[Media:070-292.pdf|Tektronix 181 Manual]] (sn 6917, color schematics, PDF)
 +
* [https://w140.com/mmm/tek-181.pdf Tektronix 181 Manual (PDF)]
 +
}}
 +
The '''Tektronix Type 181''' is a time mark generator [[introduced in 1955]].  There is a benchtop version, the 181, and a rackmount version, the RM181.  
 +
 
 +
MOD 110 substitutes a oven-stabilized1 MHz crystal oscillator (OCXO), the CO181 (Tek part number [[158-007]]), thereby achieving 2 parts per million frequency stability in a 24 hour period, the same stability as the [[180A]].
 
A 181 with the OCXO mod is a "181 S1".
 
A 181 with the OCXO mod is a "181 S1".
 
==Manuals ==
 
* [[Media:070-292.pdf|Tektronix 181 Manual (sn 6917, color schematics, PDF)]]
 
* [http://w140.com/mmm/tek-181.pdf Tektronix 181 Manual (PDF)]
 
  
 
==Internals ==
 
==Internals ==
 
Internally, the 181 is similar to the [[180A|180]].   
 
Internally, the 181 is similar to the [[180A|180]].   
 
The oscillator drives a chain of synchronized monostable multivibrators.
 
The oscillator drives a chain of synchronized monostable multivibrators.
Each multivibrator is triggered by the output of the previous stage, and
+
Each multivibrator is triggered by the output of the previous stage, and cannot be triggered again for the duration of its pulse width.   
cannot be triggered again for the duration of its pulse width.  In the 181,
+
In the 181, the pulse width ratio of one stage to the next is 1:10, i.e. when a stage triggers on a pulse at its input, it propagates that event to its output, but inhibits the next nine pulses (by time, not by counting).
the pulse width ratio of one stage to the next is 1:10, i.e. when a stage triggers  
 
on a pulse at its input, it propagates that event to its output, but inhibits the next  
 
nine pulses (by time, not by counting).
 
  
The 181 also provides a 10 MHz output.  This is generated by a 10 MHz resonator that
+
The 181 also provides a 10 MHz output.  This is generated by a 10 MHz resonator that is driven by an amplified and waveshaped copy of the 1 MHz crystal oscillator output.
is driven by an amplified and waveshaped copy of the 1 MHz crystal oscillator output.
+
Since it is a harmonic, the 10 MHz output has same relative frequency  accuracy as the reference oscillator.  
Since it is a harmonic, the 10 MHz output has same relative frequency  accuracy as
 
the reference oscillator.  
 
  
The power supply of the 181 produces +300 V and −150 V regulated voltages and  
+
The power supply of the 181 produces +300 V and −150 V regulated voltages and +400 V, −8 V, and −25 V unregulated.   
+400 V, −8 V, and −25 V unregulated.  The voltage reference is a [[5651]] tube.
+
The voltage reference is a [[5651]] tube. The output tubes for both regulators are [[12B4]] and the feedback amplifier tubes are [[6AU6]].   
The output tubes for both regulators are [[12B4]] and the feedback amplifier
+
The 181 does not contain a fan or a [[thermal cutoff]].
tubes are [[6AU6]].  The 181 does not contain a fan or a [[thermal cutoff]].
 
  
 
==Pictures ==
 
==Pictures ==

Revision as of 05:43, 18 August 2021

Tektronix 181
Time mark generator
181, early version

Produced from 1955 to (?)

Manuals
(All manuals in PDF format unless noted otherwise)
Manuals – Specifications – Links – Pictures

The Tektronix Type 181 is a time mark generator introduced in 1955. There is a benchtop version, the 181, and a rackmount version, the RM181.

MOD 110 substitutes a oven-stabilized1 MHz crystal oscillator (OCXO), the CO181 (Tek part number 158-007), thereby achieving 2 parts per million frequency stability in a 24 hour period, the same stability as the 180A. A 181 with the OCXO mod is a "181 S1".

Internals

Internally, the 181 is similar to the 180. The oscillator drives a chain of synchronized monostable multivibrators. Each multivibrator is triggered by the output of the previous stage, and cannot be triggered again for the duration of its pulse width. In the 181, the pulse width ratio of one stage to the next is 1:10, i.e. when a stage triggers on a pulse at its input, it propagates that event to its output, but inhibits the next nine pulses (by time, not by counting).

The 181 also provides a 10 MHz output. This is generated by a 10 MHz resonator that is driven by an amplified and waveshaped copy of the 1 MHz crystal oscillator output. Since it is a harmonic, the 10 MHz output has same relative frequency accuracy as the reference oscillator.

The power supply of the 181 produces +300 V and −150 V regulated voltages and +400 V, −8 V, and −25 V unregulated. The voltage reference is a 5651 tube. The output tubes for both regulators are 12B4 and the feedback amplifier tubes are 6AU6. The 181 does not contain a fan or a thermal cutoff.

Pictures