KING 70cm Telescope

• Mechanical Characteristics

• Optical Characteristics

Aperture	70 cm
F#	8
Focal distance	5600 mm
Plate scale	27 μm/arcsec (37 arcsec/mm)
Field of View (without coma)	11.7 arcmin = 18.95 mm (without corrector)
Field of View (maximum usable)	20 arcmin = 32.4 mm
Configuration
Focal station	Cassegrain
Focus mechanism	Secondary mirror

• Other Characteristics

Speeds
Pointing without correction
Tracking

• Documentation
  • ./Maintenace?: xxx, xxx
  • manual?

KING 70cm Telescope Documentation

A bit of history (according to Ulrich Grözinger's excellent memory): Design and construction at MPIA, start of project ~1981 (as filler project). A very similar copy was build. The copy was originally planned for the ​Gamsberg in Namibia, partially owned by MPIA, but eventually given away to an association of amateur astronomers. KING was erected in the Eastern dome of the Elsässer lab in May 1986, first light in June 1986, first presentation to the public at the open-house day in July 1986 (ELT designers can only dream of such an implementation speed...).

Furthermore:

Spiegel wurden von Fa. Kaufmann in Crailsheim beschafft.
Sockel ist mit Sand gefüllt (ca. 1.5t), Frontring ist ausgeschäumt
Bleigewichte (zum Auswuchten) am MPIA gegossen, Auswuchtgewichte f. Stundenachse
(Gegengewicht) können durch elektr. Taster am Pult verschoben werden.
Die Auflösung der Inkremental-Positionsencoder beträgt rechnerisch 50 marcsec. 

The telescope uses a German mount: ​link.

We uploaded the scanned original documentation including all schematics. For detailed construction drawings please consult the archive of the MPIA construction department ​link. Downloads:

• MPIA_70cm_Teleskop design A few drawings to start with giving the size scale of the hardware.
• Introduction of scanned documentation (PDF, 1.5MB) This includes instructions how to get the telescope back out of the horizon limits!
• Overview drawing from scanned documentation (PDF, 2.1MB) Includes schematic drawings of control desk, main electric installation and motor drive principle.
• The scanned electronics schematics (PDF, 22.5MB) Let's hope you will never need it.
• Scanned cabling plans (PDF, 3.7MB) Let's sincerely hope you will never ever need it.
• Various encoder datasheets (PDF, 7.1MB)
• ​Diploma thesis of Felix Hormuth lists some technical details of KING, the Lucky Imaging experiment AstraLux?, and a pointing model of the telescope, reducing the 10' uncalibrated pointing accuracy down to ~1'.
• Mirror re-coating, Felix Hormuth's notes:

Lief damals schon über das e-Procurement, sollte also im Einkauf noch einen Paper Trail geben.

Bei Bedarf in LS Hamburg anfragen, wer gerade der Ansprechpartner für's Bedampfen ist, dann mit demjenigen 
einen Termin finden und den Preis erfragen, dann über unsere Verwaltung den Transport organisieren.

Damals war dort Arnis Levits (alevits@hs.uni-hamburg.de) der Kontakt, Bedampfung hatte 1300.- netto gekostet.

Unser Primär- und Sekundärspiegel haben damals gleichzeitig reingepaßt, das macht die Sache günstig. 
Jetzt haben beide aber auch eine SiO2-Schicht oben drauf, können also schonend gereinigt werden, ohne daß man gleich das Alu ablöst.

Nach dem Wiedereinbau hab' ich nur mal intra-/extrafokale Pupillenbilder gemacht. Die sahen gut aus.
Die Spiegelhalterungen sind schon recht praezise, daher haben wir damals auf irgendwelche Neujustierungen verzichtet.
Kenne auch keine weitere Dokumentation.

Issues, Problems, Upgrade plans (should be moved to a ticket list one day)

• have a basic operations manual, in addition to the FAQs (in progress)

• setup SVN for KING telescope -> Ask Florian Briegel (in progress)

• computer: finish the upgrade to the new computer. (in progress)

• pointing model of the telescope automatic defocus (change for each filter) pointing model is off by 15-20min
• tracking issue (gets stuck, or jumps once in a while)
• cleaning of the CCD surface, by flow air.
• have a maintenance plan for camera and telescope at some point
• have a automated dome operation
  • requires motor encoders to know where you are
  • the telescope uses a German mount with the azimuth axis off-centered with respect to the dome, which requires some differential tracking between telescope and dome
• enable TRAC-blog as lab diary, by posting some basic how-to-use somewhere on these pages
• enable NX-access / integration of king in the MPIA NX environment
• have a webcam (on TRAC) from inside the dome, and maybe link other cams from outside
  • since it runs 24/7, the webcam should NOT emit any light (no LEDs etc), and ideally it sends via WLAN, so we only need a power plug

ticket administration

https://svn.mpia.de/trac/gulli/king/report