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The '''Tektronix 7B92''' is a 500 MHz dual timebase plug-in for [[7000-series scopes]].  
The '''Tektronix 7B92''' is a 500 MHz dual timebase plug-in for [[7000-series scopes]].  
It was introduced along with the [[7904]] mainframe in 1972. In 1976, it was replaced by the [[7B92A]] after some it was discovered that the 7B92's ramp generator had aberrations at the start-up of the sweep at the fastest sweep rates.
It was introduced along with the [[7904]] mainframe in 1972.  
 
According to [[Media:Tekscope 1971 V3 N4 Jul 1971.pdf|July 1971 Tekscope]], the 7B92 was designed by [[Les Larson]] and [[Bill DeVey]].  
According to [[Media:Tekscope 1971 V3 N4 Jul 1971.pdf|July 1971 Tekscope]], the 7B92 was designed by [[Les Larson]] and [[Bill DeVey]].


An "HF Sync" triggering mode is provided in which the trigger level control varies the frequency of a built-in oscillator to lock on to the input for input signals from 100 to 500 MHz, providing higher sensitivity than the direct trigger (which is specified up to 500 MHz as well).
An "HF Sync" triggering mode is provided in which the trigger level control varies the frequency of a built-in oscillator to lock on to the input for input signals from 100 to 500 MHz, providing higher sensitivity than the direct trigger (which is specified up to 500 MHz as well).
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{{Spec | Ext Trig input | 1 MΩ // 20 pF or 50 Ω }}
{{Spec | Ext Trig input | 1 MΩ // 20 pF or 50 Ω }}
{{EndSpecs}}
{{EndSpecs}}
After the 7B92 had been in production for years, it was discovered that the 7B92's ramp generator
had aberrations at the beginning of the sweep at the fastest sweep rates.
[https://vintagetek.org/years-at-tektronix-hofer/ Bruce Hofer recalls] investigating this issue and
concluding that an redesign was needed.
The redesign led to the introduction of the 7B92A, [[Patent US 4009399A]],
and the [[067-0657-00]] calibration fixture.


==Internals==
==Internals==
The 7B92 uses a discrete trigger circuit containing [[152-0177-02]] [[tunnel diodes]].
The 7B92 uses a discrete trigger circuit containing [[152-0177-02]] [[tunnel diodes]].
[https://vintagetek.org/years-at-tektronix-hofer/ Bruce Hofer recalls] investigating an issue where
early 7B92 models exhibited sweep anomalies especially near the start of the sweep.
After trying to fix these he convinced management that a redesign was needed. 
This resulted in [[Patent US 4009399A]], the [[7B92A]] update, and the [[067-0657-00]] calibration fixture.


The internal jumper for mainframe selection (7800/7900/7100 vs. slower)  
The internal jumper for mainframe selection (7800/7900/7100 vs. slower)  
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