what to do to a dob
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What to do to a Dob. Presentation by Keith Rickard 27 September 2012. Cleaning the mirror. Don’t!. Cleaning the mirror. Yuk!. Cleaning the mirror. What do you need?. Tap water Washing-up liquid 5 Litres of distilled water Cotton wool – preferably surgical - PowerPoint PPT PresentationTRANSCRIPT
What to do to a Dob
Presentation by Keith Rickard
27 September 2012
Cleaning the mirror
Don’t!
Cleaning the mirror
Yuk!
Cleaning the mirror
What do you need?
1. Tap water2. Washing-up liquid3. 5 Litres of distilled water4. Cotton wool – preferably surgical5. Vessel large enough to take the mirror6. About an hour of your time
Removing the mirrorLay the telescope on a flat surface.
Removing the mirrorLocate the tube fixing screws – note an alignment mark for replacing the cell
Alignment mark
Removing the mirrorGently withdraw the mirror cell
Removing the mirror
Removing the mirrorLocate the mirror fixing brackets
Removing the mirrorUnscrew and remove the brackets
Removing the mirrorCarefully remove the mirror from its cell
Washing the mirrorFill the trough with tap water
Washing the mirrorPut in a sparing amount of washing-up liquid
Washing the mirrorSwish the water around to get an even spread of soap
Washing the mirrorGently place the mirror in the water and leave to soak for about 15 mins
Washing the mirrorThe mirror should be about 2cm below the surface
Washing the mirrorGently swish the water across the water for about 5 mins
Washing the mirrorUse only the weight of a swab of cotton wool to remove stubborn marks
Washing the mirrorRemove the mirror while getting ready to rinse it
Rinsing the mirror
Rinsing the mirrorUse distilled / de-ionised water. This 5L container cost £3.99.
Using this water will mean no marks will be left on the surface of the mirror when it is left to dry
Rinsing the mirrorAfter rinse and drying the trough, empty the container into it
Rinsing the mirrorReplace the mirror and swish the water over it
Drying the mirror
Drying the mirrorStand the mirror on its end on a towel and let it dry naturally
Collimation – Newtonian Telescopes
Collimation – Newtonian Telescopes
This guide describes:
• Technique for visual use only
• Using a laser collimator
Why collimate?
By aligning optics as well as possible improves the performance of the telescope. Newtonians notoriously fall out of collimation very often.
Collimation – Newtonian Telescopes
Collimation – Newtonian TelescopesBefore starting…
MAKE SURE THE OPTICAL TUBE IS HORIZONTAL
You don’t want to drop anything onto the primary mirror!
Collimation – Newtonian TelescopesWhat needs adjustment?
1) Radial position of the secondary mirror
Collimation – Newtonian TelescopesSecondary sighting tool
A Kodak 35mm film pot is ideal for this purpose!
Collimation – Newtonian TelescopesWhat needs adjustment?
• Insertion of the secondary mirror
• Orientation of the secondary mirror
Left image shows an insertion and orientation adjustment is required. Right image shows the correct position.
Collimation – Newtonian TelescopesWhat needs adjustment?
• Collimation of the secondary
Centre spot on primary is required
Collimation – Newtonian TelescopesWhat needs adjustment?
• Collimation of the secondary
Collimation – Newtonian TelescopesWhat needs adjustment?
• Collimation of the secondary
Collimation – Newtonian TelescopesWhat needs adjustment?
• Introducing the Laser Collimator
Collimation – Newtonian TelescopesWhat needs adjustment?
• Collimation of the secondary
Collimation – Newtonian TelescopesWhat needs adjustment?
• Collimation of the secondary
Collimation – Newtonian TelescopesWhat needs adjustment?
• Collimation of the secondary
Collimation – Newtonian TelescopesWhat needs adjustment?
• Collimation of the secondary
Collimation – Newtonian TelescopesWhat needs adjustment?
• Collimation of the primary mirror
Collimation – Newtonian TelescopesWhat needs adjustment?
• Collimation of the primary mirror
Adjustment screws
Locking screws
Collimation – Newtonian TelescopesWhat needs adjustment?
• Collimation of the primary mirror
Collimation – Newtonian TelescopesIn summary:
• Generally, only the use of the laser collimator is required
• That means collimating the secondary & primary mirrors only
• Generally, I find the secondary needs most attention
• The process takes 1 -2 minutes
Digital Setting Circles
• They aid rapid pointing of the telescope and to allow the user know where the telescope is pointing
• This set-up is a Push-To arrangement
• Encoders are placed on each axis
• Encoders are connected an interface box
• The interface box is then connected to a computer
• Software on the computer, say a planetarium program, gives the user access to a database of objects to find, etc.
Digital Setting CirclesThe Altitude Encoder
Digital Setting CirclesThe Azimuth Encoder
Digital Setting CirclesThe Interface Box
The Dave Ek Digital Setting Circles printed circuit board - $24.00
Digital Setting CirclesThe Interface Box
Digital Setting CirclesThe Interface Box
Digital Setting CirclesThe Interface Box
Digital Setting CirclesThe Interface Box
Digital Setting CirclesThe Interface Box connected to a PC serial port
Digital Setting CirclesThe Interface Box connected to a Bluetooth serial adapter
Digital Setting CirclesSoftware – Android Smart Phone
• Sky Safari Plus (cost ~£8.00)
• Massive database of different types of objects
• Contains 2.5 million stars – excellent for zooming in to see the star filed as seen in the eyepiece – makes spotting the object more easy.
• Easy telescope control using
Digital Setting CirclesSoftware – PC Planetarium
• The software which use ASCOM drivers will work
• Sky Map Pro does
Digital Setting Circles
Digital Setting Circles
The End