Home 

ben at davies dot net                                                                                                                                                                                                        111_1106-72.jpg (38234 bytes)

 

The 12.5" Newtonian Telescope

   

ATM & ASTRONOMY LINKS         

Astronomy                 Astronomical Objects   Balancing     Baffling         Books          Calendar     CCD Imaging   Clocks     

Collimation               Coordinate Systems     Cosmic Rays  Dictionaries   Electrical, Misc     The Eye       Eyepieces

Field Rotation in Alt-Az Mount         Floatation Cells           Focuser         Gearing      Image Brightness 

Location    Mirrors   Mechanical,Misc    Motorized GoTo    Mount Design    My favorite mounts     Observing    

Optical Coatings         People        Pointing            Point of View      Polar Alignment    Secondary Mirror 

Seeing     Spider         Time           Tube & Truss   Truss and Tube Parts     Weather

 

             Mirrors - Vendors

  1. Steve Swayze

  2. Galaxy Optics

  3. Carl Zambuto

  4. Pegasus

  5. Nova

  6. O'neil Photo

  7. Discovery

  8. Company 7

  9. Bob Jones

  10. Steve Kennedy

  11. Oldham      UK

  Grind your own mirror 

  1. Mel Bartels

  2. Bob May

  3. Steve Lee

  4. Jeff Baldwin

  5. Notes from John Dobson

  6. Mel Bartels  Polishing Notes

  7. Dave Thomson

  8. Laurie Hall

  9. Berthold Hamburger  -  Tile grinding tool

  10. Ricardo Dunna - grinding with pictures of focault tests

  11. John Zeigler

  12. Richard Combs

  13. University of British Columbia  -  and Marc Frantz       Liquid mirrors

  14. Bill Kelly Alan Adler  -  instead of grinding,  flex the mirror   And  Sky and Telescope

Jim Crombie - Mirror Grinding Machine

Mirror blanks and Supplies

  1. Hextex

  2. Newport Glass

  3. Glass Fab

  4. Schott  -  Zerodur

  5.  OR

  6. Andre Taillon - BVC Glass

  7. GotGrit

  8. Salem Distributing Co

  9. Galvoptics  -  UK source

Testing and refiguring

  1. Galaxy - interferometer testing

  2. Swazye

  3. Scott Rychnovsky

Optical Coatings

  1. Aluminum Coating

  2. Michael J Coslo - Notes on silvering

  3. ATM Resource List

  4. Galaxy - vendor

  5. Majestic - vendor

  6. Clausing - vendor

  7. Spectrum - vendor

    8.

Cleaning Optics

Testing and rating mirrors

  1. Mel Bartels 

  2.  Aberrator - Startest software

  3. Suiter

  4. Galaxy

  5. Glen Bankston  -  Foucault mirror tester

  6. Dave Harbour   -  Foucault Primer

  7. Duvall  - slitless tester

  8. John Upton - Windows simulation for ronchi test

  9. Peter John Smith - shearing inteferometer

  10. Jim Burrows - Mirror mathematics 

  11. Mark Holm - Couder Mask

  12. Carlin / Slater - Couder Mask 

  13. Allar Saviauk - building a Foucault tester

  14. James Lerch -  Robofoucault     Dave Bevel's page

  15. Dave Rowe - Foucault Analysis Program

  16. Peter Abrahams  -  History of testing mirors

Newtonian Telescope Secondary mirror

  1. Legault - effects of the obstruction

  2. Scott Rychnovsky  -  Secondary holder

  3. Mel Bartels  -  program to calculate diagonal size

  4. Dale Keller's Newt -  diagonal offset        comment by Gary Seronik

  5. Nils Olof Carlin  -  offset secondary

  6. Harry Kambanis - spreadsheet to calc diagonal size

  7. Gary Seronik - diagonal size not a function of f-ratio  

    8.

  8. SEDS - dew heater circuit

  9. Don Clement - dew heater circuit

  10. Steve Misterek - Making a cassegrainian secondary

    11.

  11. Mike Lockwood  -  fabricating a cassegrain secondary

  12. Gary Bloom -  Vignetting at the secondary

 Secondary mirror - vendors

  1. Nova

  2. Protostar - fused silica

  3. Antares

  4. Newport Glass  

 Flotation cell - Calculate supports

  1. David Lewis   -  Calculate mirror supports - Plop

    2.

  2. Mark Holm - Plop, FAQ

  3. Cell

  4. Johan Vanbeselaeres

  5. Nils Olof Carlin - edge support

Alt-Az Telescope Field Rotation

  1. Yi-Zen    Field Rotation calculations

  2. Harry Kambanis  -  spreadsheet to calculate field rotation

    3.

Flotation cells - examples

  1. Ben Davies

  2. Astatic Supports

  3. Frédéric Géa   Astatic Supports

  4. Bruce Sayre - on astatic supports

  5. Steve Lee

  6. S*t*a*r

  7. Jan Van Gastel

  8. Albert Highe

  9. Dave Bevel

  10. Laurie Hall

  11. Jim O'Malley

  12. Al Frances - motorized collimation

  13. Bruce Sayre

Focuser - general information

  1. Paint your new focuser - ccd - anodizing reflects infrared

  2. Ron Newman - OK, anodize it anyway

  3. Dale Keller - spare in travel

Focuser - make your own

  1. Steve Lee - slide focuser

  2. Berthold Hamburger  -  slide focuser

  3. Glen Bankston -  crayford

  4. Chris Stewart - crayford

  5. Laurie Hall - rack and pinon

  6. Bill Arnett - focuser modification

Focuser - vendors

  1. Starlight Feathertouch -  I have one and mechanically 'tis a thing of  beauty

  2. JMI - crayford

  3. Don Clement  - compliant hinge, no drawtube

  4. Kine - a helical crayford

  5. Burgess - crayford

  6. Van Slyke - crayford 

  7. Moonlite - crayford

  8. PCFocus - focusing software for the pc

  9. Optec - Temperature compensating focuser

Newtonian Telescope Spider - diagonal holder

  1. Steve Lee - 4 vane offset spider

  2. Texereau - page 127-128   4 vane offset

  3. Bryan Greer - atm, spider diffraction

  4. Steve Swayze - home made 4 vane offset or coincident

  5. Nils Olof Carlin - hacksaw spider

  6. Protostar - vendor - 4 vane

    7.

  7. VSI -vendor

  8. Silent Observer - wire spider

  9. Jack Schmidling

  10. Mike Spooner   variation on the curved spider

  11. Destiny  -  curved spider

  12. Alan Scott - wire spider

  13. David Suiter - diffraction spike intensity   The missing link

 Eyepieces

  1. Gary Wolanski  -  easy to make crosshairs

  2. Jeff  DeTray  -  Make you own

  Newtonian Telescope Tube / Truss

  1. Don't paint it white - John Dobson  or Portuesi -  white paint contains titanium dioxide, a  good infrared emitter

  2. Paint it white - Tom Ryan

  3. Don't Paint it white - Las Campanas    Bron Tapes, Inc. 7343 Carroll Road San Diego, CA 92121 (858) 530-0391

  4. Florida Solar Energy Center - reflectivity and emissivity of roofing materials

  5. Anthony Cook - serrurier truss description

  6. Steve Lee - tube in a Serrurier truss - German equatorial mount

  7. Chuck Hards = Serrurier Truss

  8. Bruce Sayre -  altitude/ azimuth mount

  9. David Mark North - cantilever tubes

  10. Albert Highe - cantilever tube

  11. Bryan Greer - Thermal action inside the tube - fascinating, but you need patience or a fast connection

Tube / Truss Parts

  1. Yazoo Mills - source of cardboard tubes

  2. Essex - UK cardboard tubes

  3. Parks - fiberglass tubes

  4. Hastings  -  aluminum tubing

  5. CST Sales - carbon fiber rods

  6. Dave Rowe - Composits - Carbon fiber tubes

  7. Custom Telescopes UK

  8. ScopeStuff  -  Scope covers

    9.

 Baffling

  1. Richard Combs   -  keep the light away from the main mirror

  2. Baldwin - keep the light out of the focuser

  3. Seronik - painting the surfaces    S&T Article

  4. Bartels - software to calculate baffle locations

  5. Steve Lee - forget baffles

  6. Nils Olof Carlin - agrees with Lee

  7. Gary Seronik  -  Also agrees with Lee

  8. laser generated silicon spikes - here is the kind of surface we are looking for

  9. emissivity primer - emissivity - usually measured as 1-relfectivity.

  10. material emissivity properties

Gear Making

  1. Eric Green  -  molding a gear with JB Weld

  2. Rex Kindell  -  double threaded rod gear       

  3. Chuck Shaw - comment on threads

  4. Don Clement  -  Flexible rod drive

  5. Eric Green  -  molded gears  

  6. Chris Heapy - Notes on making a worm drive

  7. Jim Sapp  -  Making worm gears on a lathe

    8.

  8. Gary Wolanski - Cutting gears with a spiral tap

  9. Gary Wolanski - clutch assembly

  10. Frank Melsheimer -copmparing different drive systems

  11. Jan Van Gastel - Belt Drives

  12. Scopecraft - general discussion of roller drives

  13. ObservatoryScope  -  Size banding for a hybrid drive

Newtonian Telescope Collimation:

  1. Nils Olof Carlin  - And more

  2. Mel Bartels - Optical Collimation

  3. Thiery Legault   collimation by star test

  4. John Reed   using a laser to insure the various axes are coincident

  5. Bratislav - Why the laser 'collimation' is not by itself, enough

  6. Steve Bell    Mechanical Collimation

  7. Brian Greer  peephole collimator

    8.

  8. Scott Hesser and Kate Perry -  collimation with a Hartmann mask

    9.

  9. Mogens Winthers  -  another method of Hartmann Collimation

Balancing: 

  1. Thompson Observatory  -  Balancing a GEM

  2. Starizona  -  Balancing

    3.

   Time: 

The Right Ascension of a stellar object is just the local sidereal time at which it passes directly overhead.

  1. Fiona Vincent  -  Sidereal Time

  2. Alan Buckman  -  explaining sidereal time

  3. USNO Compute local apparent sidereal time

  4. Rick Fisher - explanation of different flavors of time

  5. Dirk Husfeld - astronomical timekeeping

  6. USNO - what is universal time?

  7. Alan McRobert - Time and the Astronomer

  8. Connecttotel - your computers clock, dos, non internet time sources - radio, modem, gps

    9.

  9. Framis Group  -  java calculator of various astronomical times:  utc, lst, gst, jd

  10. Markus Kuhn - history of the calendar

  11. Markus Kuhn - International date and time standard notations

    12.

  12. Kevin Karney  -  the equation of time

  13. Steve Allen  -  what Lick Observatory does about time

    14.

  14. USNO  -  Time zones of the world - map

  15. Danny Hillis 10,000 year clock

Clocks

  1. Wolfgang Renz  -  Using Time Servers to update your computers' clock - the rules

  2. Dimension 4  adjust your computer's bios clock

  3. About Time -  Synchronize your computer's clock over the internet 

  4. Network Time Protocol (NTP) - synchronizing time over a network

  5. USNO - master clock

  6. National Institute of Standards

  7. world time server

  8. US Gov  - current global sunlight/darkness map

  9. Bill Rossi  -  radio clocks

    10.

  10. Jonathan Buzzard- Radio Clock for a PC

  11. XNote - shareware stopwatch / countdown timer

  12. Larry Bogan -  sidereal time calculator

  13. NOAA - sunrise and sunset, solar noon

  14. Tom Clark  -  Totally accurate clock

  15. Hans Summers  -  Make a sidereal clock

  16. Shouji Morimoto - freeware  multiple stopwatch

    17.

  17. NLSA - Time and location from a GPS to a computer

  18. Matt Oltersdorf  - Astronomer's Digital Clock:  Local, UTC, Local and Greenwich Sidereal Time, Julian Date, event capture

  19. Steven Mogg - Sidereal wall clock

Calendar

  1. AAVSO - Julian Day Calculator, convert JD to UT

  2. Riccardo Papini -  Spreadsheet conversion, Date to JD

  3. Obliquity - history of the calendar

    4.

  4. Millennia Calendar - Shareware 7,000 year calendar.  Julian Gregorian, Egyptian, Hebrew, Coptic, Islamic,  more

  5. Jonathan Buzzard - Calculate number of days between 2 dates

 Location

  1. Heavens Above - locations for the entire world

  2. Tiger Map Server - longitude and latitude

  3. Juggling - longitude and latitude

  4. Obliquity - how far is it from here to there?

  5. terraserver - USGS maps to find location

  6. noaa - magnetic declinations

  7. DSS  -  off planet sites

21. SEEING

The greatest thing a human soul ever does in this world is to see something.....To see clearly is poetry, prophecy, and religion, all in one.     John Ruskin, 1819 - 1900

  1. Damian Peach - The atmosphere and Observing

    2.

  2. Majewski - The physics of turbulence and seeing

  3. Jack Schmidling

  4. Dwight

    5.

  5. Arizona State University - Looking Through the Earth's Atmosphere

  6. Bryan Greer - focal ratios and seeing

  7. Viekko Makela - estimating limiting magnitude

  8. Jerry Lodriguss

    9.

  9. University of Rochester  -  Lecture notes on seeing

  10. Cyril Cavadore  -  Seeing and Turbulance

  11. Stellar Products - Adaptive optics you can buy for 50k

  12. Canadian  Meteorological Center - seeing forecast 

  13. Wilderness Center  -  Limiting Magnitude

  14. UKIRT - Improving seeing with a fan blowing across the main mirror

    15.

  15. The Brightness of the Night Sky

POINTING

  1. Steve Lee

  2. Frank Melsheimer

  3. Patrick Wallace

  4. Mel Bartels

    5.

  5. Marc Buie - General Analytical Pointing Model - written in IDL

  6. Alan Buckman

  7. Toshimi Taki         Equations for pointing the telescope  

  8. S B Foulkes   Starlight Express XS Guider

  9. Chuck Shaw - Quick Cam Autoguider

  10. Marty Niemi Quick Cam

  11. Mel Bartels autoguiding

  12. SBIG  STV

THE EYE

What we see is not the world as it actually exists at all.  It is an analogue of that and a very incomplete one.  If  the case were otherwise atomic physics would be easy.  Most of it would be self evident.   David Pie          

  1. Mike Linnolt - The eye

  2. Mel Bartels  -  Visual Astronomy

  3. Maurio Motta 

  4. Dan Bruton

  5. Nils Olof Carlin

  6. Aart Olsen

  7. Jim Burrows

  8. red is the best color for preserving night vision

  9. Doug Kniffen - red is not the best color for preserving night vision

  10. Gordon Bond  -  Red Revisited

  11. Mel Bartels - dim white is the best color for preserving night vision

  12. Leibrock, Reuter, Lamb - Dark Adaptation

  13. Mark D Holm - eye sensitivity / wavelength of light

IMAGE BRIGHTNESS

  1. Steve Lee

  2. Ben  

    3.

  3. Robert J Vanderbei  -  aperture, focal length, and f-ratio

  4. Al Nagler  -  Choosing your telescope's magnification

POLAR ALIGNMENT

Watch the stars and from them learn.
To the Master's honor all must turn,
Each in its track, without a sound,
Forever tracing Newton's ground.
                   Albert Einstein

  1. S*T*A*R     drift method

  2. Bruce Johnson  -  drift method

  3. Ron Wodoaki  -  drift alignment - short and sweet

  4. Starizona  the mechanics of drift alignment

  5.  Brayebrook - align the observatory

  6. Jet Propulsion Labs - Finding true north

  7. Greg Beach - Align the telescope photographic method

  8. Scott Tucker   drift  using the double crosshair eyepiece

  9. Wallis and Provin

  10. Celestron     drift method

  11. Phillip Perkins   drift method LX 200

  12. Jim Hall       I hate the drift method:  ccd method

  13. Mel Bartels - polar align with Scope.exe

  14. Rick Kellogg - polar align a gem with a Sbig STV

  15. Peter Enzerink  polar alignment in the Southern Hemisphere

  16. Zac  Polar alignment - drinking straw method

  17. Dave Rowe    selecting drift stars and refraction

  18. John McCubbin  -  ccd method

  19. Greg Beach - Polar alignment using photographic plates

  20. Clay Sherrod  -  dead reckoning method

  21. Michael Covington  -  Iterative method

  22. Jim Sapp  -  Polaris in relation to the pole

    23.

  23. Larry Webber / Steve Brady  -  PoleAlignMax     alignment software for use with a ccd camera

Dictionaries of Astronomy and ATM

  1. Annemie

  2. Bill Allen      Aerospace

    3.

  3. NASA - Imagine the Universe

  4. Del Stanton - center of curvature of a  paraboloid

  5. Veikko Makela     common astronomical words across European languages

  6. Celesrton      optical terms

  7. Steve Lee   annoying misuse of terms

  8. Bill Arnett    planetary dictionary

  9. NASA    acronyms 

  10. Mark Deprest - Naming Astronomical Objects

Weather

  1. Clear Sky Clock

  2. Accuweather

  3. Spaceweather

    4.

  4. NE Pacific Water Vapor Map

  5. Real Time US composite satellite image

  6. Full Goes - Eastern Pacific IR    North East Pacific - IR

  7. NOAA  -  Smoke and particulates map

  8. AstronomyWeather -  Number of  cloudy days - US cities

Astronomical Objects: 

Sometimes I think we're alone in the universe. Sometimes I think we're not.  In both cases the thought is equally shocking.      Arthur C. Clarke

  1. The Moon - Bill Arnett

    2.

  2. James B Kaler -  The Nature of The Stars

  3. sci.astro

  4. Nearest Stars

  5. Eclipsing Binaries  Dan Bruton

  6. Steve Moore - planetary data

  7. The Nine Planets - Bill Arnett

  8. Messier deep space objects - SEDS

    9.

  9. Delta Aquarids - Gary Kronk

  10. Currently visible comets - Gary Kronk

  11. USNO - The Washington Double Star CAtalog

  12. Michael Schwartz - Hunting Supernovae

Coordinate Systems

  1. John Ross - Sky Coordinates

  2. Spherical Coordinates

  3. Fiona Vincent - HA-dec equatorial system

  4. Fiona Vincent - RA-dec equatorial system

  5. Fiona Vincent - Convert between at-az and equatorial coordinates

  6. Jason Harris  -  Hour angle

Point of View

  1. Eclipsing Binaries - Java animation - Terry Hurter

  2. NASA - Solar System Simulator

People

  1. John Evans - hunter of supernovae - interview 

  2. John Dobson - brief biography

  3. Chris Plicht - biographies

  4. Dmitri Maksutov  Дмитрий Дмитриевич Максутов

  5. Cecilia Payne-Gaposchkin

  6. George Biddell Airy 1801 - 1892  and how it came to be that the Prime Meridian passes through Greenwich  England

  7. Subrahmanyan Chandrasekhar

My Favorite Mounts

  1. Zach Helmburger - hand driven clock drive - Camera mount

  2. Amateurs of Auvergne - Horseshoe mount

  3. Alt-Alt-Az  -  Tracy Wilson's 3 axis prototype Off line now, will return at some point

    4.

  4. Evan Williams - Double arm camera drive

CCD Imaging

  1. César Briceño Avila - CCD camera chracteristics

  2. Al Kelly  -  Basics of processing images

    3.

  3. Jim Burnell  -  matching the camera to the telescope

  4. Apogee  -  series of good articles on ccd's for astronomy

  5. Starizona  -  Dark, flat and bias frames

    6.

  6. Simon Tulloch - The basics of ccd arrays

  7. KPNO - Kitt Peak - Paint for light box, flat field screens (last paragraph)

  8. Lumetronics - White reflective paint

  9. E. Norman Walker - CCD Photometry

  10. Radu Corlan - Tables for scintillation noise

  11. ING La Palma and  AAO   and ESO - Blank Areas of Sky for Flat Fields           Guide8 .tdf files for displaying the empty fields

  12. NASA Heasarc - Among other things this software allows you to view and edit pixel values in a spreadsheet

  13. Christian Bull - designing a spectragraph

    COSMIC RAYS     and other radiation effects on CCDs

  1. Don Groom,  Michael Anderson - Potassium contamination in cover glass   and also    and more

  2. Sven Nielsen  -  Cosmic Ray / Natural Radioactivity in CCD

  3. Don Groom - Cosmic Rays and Other Nonsense...      And also

  4. Ben Davies - Potassium contamination in cover glass of Kodak Chips    Also:

    5.

Motorized GoTo Telescope

  1. Mel Bartels

  2. Lenord Stage - implementations of Mel Bartel's system

    3.

  3. Dan Gray - Sidereal Technologies  Servo controllers + ASCOM interface

  4. Nexstar  -  Batteries

  5. Michael Swartzendruber - Telescope voice control

  6. Dave Rowe - Making direct drive motors

MOUNT DESIGNS

  1. Joe Garlitz - A-Thermal design

  2. Tom Krajci

  3. Ben Davies - Periodic error in split ring / horseshoe bearing

  4. Marc Baril - Maksutov-Cassegrain

  5. Brian Lula  -  GEM

  6. Bryan Greer - Thermal Behavior in tubes

  7. Mel Bartels - Trilateral mount

  8. Greg Babcock - half fork design

    9.

  9. Don Davies  -  Equatorial Platform

  10. Roger Sinnott - double arm barn door mount

  11. Ivan Krastev - Flow chart of the various types of telescope arranged by mirror design

ASTRONOMY:

  1. Andre James Clayden - calculating the diameter and depth of lunar features

  2. Tom Krajci -  Getting started in the science of astronomy

  3. NASA - Eclipsing Binaries

  4. DWE Green - reporting a new comet

  5. Tenagre  -  How to discover supernovae

  6. Supernova network  -  list of all current supernovae

    7.

  7. SEDS - Naming Stars

  8. Veikko Makela - Estimating limiting magnitude

    9.

  9. J J O'Connor and E F Robertson    Orbits and gravitation

    10.

OBSERVING:

  1. Jay  Leblanc -  Excellent graphic of moon rise and set times/dates

  2. Think Astronomy - Shareware.  Locations of deep sky objects relative to the galaxy.

MISCELLANEOUS ELECTRICAL

  1. Mark Keitel - Battery Power                       A better deal on the inverter

  2. Jim Heilman - Pulsing cirucit for the Telerad 

    3.

  3. Tom Campbell   - boost 12volts to 18volts

  4. Aaro