7J20: Difference between revisions

Jump to navigation Jump to search
No edit summary
No edit summary
Line 8: Line 8:
series=7000-series scopes|
series=7000-series scopes|
manuals=
manuals=
* [[Media:70-1642-00.pdf|Tektronix J20/7J20 Service Manual (PDF)]]
* [[Media:70-1642-00.pdf|Tektronix J20/7J20 Service Manual]]
* [[Media:70-1641-00.pdf|Tektronix J20/7J20 Operators Manual (PDF)]]
* [[Media:70-1641-00.pdf|Tektronix J20/7J20 Operators Manual]]
* [[Media:Tek 7j20 interim service manual.pdf|Tektronix J20/7J20 Interim Service Manual (PDF)]]
* [[Media:Tek 7j20 interim service manual.pdf|Tektronix J20/7J20 Interim Service Manual]]
* [[Media:070-1743-00.pdf|Tektronix 016-1000-00 RSS External Normalizer Manual (PDF)]]
* [[Media:070-1743-00.pdf|Tektronix 016-1000-00 RSS External Normalizer Manual]]
* [[Media:TEK RSS Brochure.pdf|Tektronix J20/7J20 Brochure (PDF)]]
* [[Media:TEK RSS Brochure.pdf|Tektronix J20/7J20 Brochure]]
* [[Media:RSS Applications.pdf|Tektronix J20/7J20 Application Notes 9 & 11 (PDF)]]
* [[Media:RSS Applications.pdf|Tektronix J20/7J20 Application Notes 9 & 11]]
* [[Media:RSS R&D Article 11-1974.pdf|R/D Article - November 1974 (PDF)]]
* [[Media:RSS R&D Article 11-1974.pdf|R/D Article - November 1974]]
* [http://w140.com/tek_7J20_from_1975_cat.pdf Section in 1975 Catalog in 7J20 (PDF)]
* [http://w140.com/tek_7J20_from_1975_cat.pdf Section in 1975 Catalog in 7J20]
* [[Media:TEK 7J20 Advertisement 06-1975.pdf|Tektronix J20/7J20 Advertisement - June 1975 (PDF)]]
* [[Media:TEK 7J20 Advertisement 06-1975.pdf|Tektronix J20/7J20 Advertisement - June 1975]]
* [[Media:Jere marrs rapid-scanning spectrometry.pdf|Jere Marrs, "Rapid-Scanning Spectrometry" (PDF)]]
* [[Media:Jere marrs rapid-scanning spectrometry.pdf|Jere Marrs, "Rapid-Scanning Spectrometry"]]
* [[Media:Peter burke fast-scan spectrometry.pdf|Peter Burke "Fast-Scan Spectrometry" (PDF)]]
* [[Media:Peter burke fast-scan spectrometry.pdf|Peter Burke "Fast-Scan Spectrometry"]]
}}
}}
The '''Tektronix 7J20''', which only appears in the 1975 catalog, is a "rapid scan" optical spectrometer for the 250 nm to 1100 nm region.
The '''Tektronix 7J20''', which only appears in the 1975 catalog, is a "rapid scan" optical spectrometer for the 250 nm to 1100 nm region.
Line 26: Line 26:
The external enclosure is labeled "J20".
The external enclosure is labeled "J20".
It has controls for the optical components (grating, filters etc.) on one side and an input aperture on the other.
It has controls for the optical components (grating, filters etc.) on one side and an input aperture on the other.
==Internals==
The instrument is based on a [[wikipedia:Monochromator|Czerny-Turner Monochromator]], in essence a narrow slit followed by a [[wikipedia:Diffraction grating|diffraction grating]].
A [[wikipedia:Vidicon|vidicon tube]] scans the optical spectrum and produces a periodic electric signal which is then displayed by the scope mainframe.
[[File:7J20-principle.jpg | thumb | 400px | center | Operating principle (click to enlarge) ]]
The internal vidicon horizontal scan voltage corresponds to wavelength, but not in a linear way.
To provide a linear nm/div horizontal display on the 7000-series mainframe, the vidicon horizontal scan signal is passed through a function generator IC, the [[155-0106-00]] (U1550 and U1590), which implements an interpolated lookup table.
Inside the J20, there are 40 trimmer potentiometers that allow the lookup function to be tweaked so that the horizontal scale of the system is accurate.
[[File:Tek_j20_interim_normalizer2.png | thumb | 400px | center | Normalizer (click to enlarge) ]]
The 7J20 is very rare. According to Dennis Tillman, ''Best estimate is ~40 were actually built.''


{{BeginSpecs}}
{{BeginSpecs}}
Line 54: Line 42:
==Links==
==Links==
* [https://youtube.com/watch?v=7zR4Os6JEac 7J20 in operation @ VintageTek Museum] (YouTube)
* [https://youtube.com/watch?v=7zR4Os6JEac 7J20 in operation @ VintageTek Museum] (YouTube)
==Internals==
The instrument is based on a [[wikipedia:Monochromator|Czerny-Turner Monochromator]], in essence a narrow slit followed by a [[wikipedia:Diffraction grating|diffraction grating]].
A [[wikipedia:Vidicon|vidicon tube]] scans the optical spectrum and produces a periodic electric signal which is then displayed by the scope mainframe.
[[File:7J20-principle.jpg | thumb | 400px | center | Operating principle (click to enlarge) ]]
The internal vidicon horizontal scan voltage corresponds to wavelength, but not in a linear way.
To provide a linear nm/div horizontal display on the 7000-series mainframe, the vidicon horizontal scan signal is passed through a function generator IC, the [[155-0106-00]] (U1550 and U1590), which implements an interpolated lookup table.
Inside the J20, there are 40 trimmer potentiometers that allow the lookup function to be tweaked so that the horizontal scale of the system is accurate.
[[File:Tek_j20_interim_normalizer2.png | thumb | 400px | center | Normalizer (click to enlarge) ]]
The 7J20 is very rare. According to Dennis Tillman, ''Best estimate is ~40 were actually built.''


==Pictures==
==Pictures==
Retrieved from "https://w140.com/tekwiki/wiki/7J20"