KING 70cm Telescope

• Location

Name	MPIA, Heidelberg
Latitude	N 49º 23' 44"
Longitude	E 08º 43' 25"
Altitude	560 m

• Mechanical Characteristics

Mounting	German Equatorial mount (49º 23m)	​link
Structure
Right ascension axis
Declination axis

• 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
Focus range

• Other Characteristics

	GROB = fast	~ 90 deg/min
Speeds	MITTEL = medium	~ 30 deg/min
	FEIN = slow	~ 1 deg/min
Pointing accuracy without correction	10-20 arcmin
Pointing accuracy with correction	< 1 arcmin
Tracking	15 arcsec/sec
Unguided observations	up to 180 s

• 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...).

attached documents

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. 

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.
• 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.

Upgrade plans (in the future)

• Pointing model of the telescope shall be recalibrated with images with uniform distribution on the sky. A minimum of ~ 40-65 images are needed. If you want to volunteer for this task, please contact Conchi Cardenas.
• Automatic defocus (change for each filter. Some runs shall be perform for each filter and epoch. If you want to volunteer for this task, please contact Conchi Cardenas.
• Tracking issue (gets stuck, or jumps once in a while). Investigate this issue is needed too. If you want to volunteer for this task, please contact Conchi Cardenas.
• Maintenance plan for camera and telescope.
• 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