HAG 24”RC v2.4 Sep 2016
Training and
Information Booklet
24” Telescope Guide
Steve Broadbent
Version 2.4 September 2016
HAG 24”RC v2.4 Sep 2016
24” REFLECTOR TELESCOPE
OPERATING PROCEDURE
The 24-inch reflector telescope is of Ritchey Chretien style, with motorised
declination and Right Ascension drives and a computerised “GoTo” control
system operated using the Handset or by a computer planetarium
program.
The procedure described below is for the Handset operation when using
eyepieces. The Handset provides facilities for calibration (alignment),
object GoTo, and variable slew and tracking rates.
Solar system objects are not included in the “GoTo” database and the
Handset has no provision for entering RA and Dec coordinates for “GoTo”.
Note that to maintain balance the OTA cover should always be
removed prior to moving the telescope for any reason.
SETTING UP PROCEDURE
1.
Check wind speed. Collect the 24” eyepiece case from the
instrument cupboard. Take and switch on a radio and leave another
one on the clubhouse table switched on.
2.
Open door fully and hook in open position, or close the door. Lock the
padlock on the staple. On entering the dome, check floor for trip
hazards; be careful at all times not to bump into the telescope.
3.
All the lighting switches have indicator lights, orange - off, blue - on.
Switch on the dome roof white lights (lowest switch with the orange
light). Switch on red lights (push top On/Off/Dimmer switch nearest
the door). The white wall lights may also be switched on if required
with the switch adjacent to the red light switch.
The lights can also be operated by the wireless remote control unit.
This is normally located on the Control Desk. (0=off, 1=on).
4.
Remove the desk cover and put the eyepiece case on the desk.
5.
Remove the scope cover. If it is wet fold it with the wet side in. Stow it
off the floor either on the bottom shelf of the desk or in the monitor
cover.
6.
Remove the telescope OTA tube cap and check the condition of the
main mirror. If it is OK to proceed hang the cover on the hook by the
desk. Remove both caps from finder scope and stow all caps
correctly.
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HAG 24”RC v2.4 Sep 2016
Do NOT attempt to touch the optics. If there is a problem with
the optics, report it via the website members’ area fault report
form.
7.
If on, switch off main dome lights. Place shutter operating handle on
the shaft and lift the locking latch on inside of dome shutters and use
handle to wind open the dome shutters. Remove the shutter
operating handle and place on the dome shelf.
8.
Disconnect the 4 hold down chains from the dome hooks and hang
the top links on the white hooks at the top of the chain channels. This
releases the dome from the wall and allows the dome to be rotated by
the electrical dome rotation gear.
9.
Switch on the dome drive power switch (rocker switch with red light
panel on socket next to the dome motor).
Whenever the dome is moved, always check for obstructions
and be ready to stop and warn anyone in the dome.
10. Move the dome to the required position. This can be done using the
handset or the Microprocessor Control Unit (MCU) on the Control
Desk. (See pages 11-14 for instructions for the MCU).
Remember the direction of rotation and when moving or parking the
dome ensure that it is rotated in the opposite direction to prevent
cables being twisted. Ensure that during use the dome is never
rotated by 360 degrees or more.
11. Check that all the OTA balance weights on the top and bottom of the
OTA are at the eyepiece end of their rails.
12. Remove the tube cap from the 2 Inch tube in the centre of the base of
the OTA (3 screws) and insert the star diagonal and the desired
eyepiece. It is usual to select a long focus eyepiece first to centralise
the object before moving to a higher power eyepiece. Ensure that
both the star diagonal and eyepiece are secure.
13. Switch on the Focuser at the power socket and scope drive system at
the Drive Control Unit. The telescope should always be calibrated on
a reference star at the beginning of a session.
At this point it is essential the user is familiar with the later
section “USING THE HANDSET” for instructions on moving the
telescope. The telescope should never be rotated more than 3/4
of a full turn from the parked position, or pointed below the
horizon. Ensure this does not happen when parking the scope.
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HAG 24”RC v2.4 Sep 2016
THE TELESCOPE SHOULD NEVER BE MOVED BY HAND.
NOTE: Drive motors tend to overrun in slew mode when in
manual control; lift finger off arrow key shortly before desired
position or reach required position using a slower move speed.
14. Check there are no obstructions to the movement of the telescope.
15. Choose a suitable reference star to calibrate the telescope.
(see lists on pages 8-10).
The star must be between southeast and southwest in direction
and calibration must be done with the telescope on the east side
of the mount or subsequent “GoTo” commands will result in
incorrect movement.
Choose a star that will result in the finder scope being in an easily
accessible position.
16. Drive the telescope to the desired reference star using the finder
scope for initial alignment and the main eyepiece for final adjustment.
Whenever the scope is moved, warn anyone in the dome.
The finder has an illuminated reticule which is switched on with the
silver knob at the side of the eyepiece. Switch the reticule off as soon
as you have centred the star to preserve battery life.
Rotate the star diagonal to place the eyepiece in a convenient
attitude for use and check it is secure. Adjust the slew rate to a
slower value if necessary to centre the star in the main eyepiece.
When moving the telescope ensure that the OTA always points
above the horizon.
17. Calibrate the scope on the reference star. See Calibration later.
Notes:
Manually driving the telescope to targets between northwest and
northeast may result in the telescope losing orientation. Use the
GoTo facility for targets near north whenever possible.
Do not touch the two black levers on the mount. These are preset
clutches that, if moved, will result in loss of calibration of the
telescope.
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HAG 24”RC v2.4 Sep 2016
CLOSING DOWN
1.
Place the dome shutter operating handle onto the operating shaft
and wind the shutters together, lifting the latch just before they are
brought together then make sure the latch drops locking the shutters closed. Remove handle and place it on the dome shelf.
2.
Switch on main dome lights.
3.
Move dome round to its parked position:
Use the handset to rotate the dome in the opposite direction to its
initial direction. Accurately align the dome hooks with the wall
chains using the white mark as a guide. If the dome is moving to
the right, overshoot the white mark and align the white marks
moving the dome to the left.
4.
Switch off the dome drive power switch by the door and then attach
and lock down the 4 dome chains.
5.
Drive the telescope to the parked position (facing south on the east
side of the mount) ensuring that it has not rotated 360 degrees (so
that any wiring does not wrap around the mount). Ensure that the
OTA always points above the horizon.
6.
Switch off the Drive Control Box at the base of ‘scope. Do not
switch off the Drive Control Unit power supply at the 13 A
Switch Socket Outlet.
7.
Remove eyepiece and star-diagonal and return them to their
storage boxes. Replace eyepiece tube cap.
8.
Check that the finder reticule illumination is turned off and replace
the 2 finder caps and telescope OTA tube cap.
10.
Switch off all the power sockets except the Drive Control and the
heater at the base of the pillar. Check power sockets behind the
desk are off.
11.
Put cover back on telescope. Check dome is left tidy.
12.
Go through the dome checklist by the door.
13.
Check radio, eyepiece box, all ancillary equipment and belongings
have been gathered. Switch off all lights, close and lock the door.
14.
Return eyepieces to cupboard and switch off radio and put in
charger.
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HAG 24”RC v2.4 Sep 2016
USING THE HANDSET
1. Display of RA coordinate
2. Display of DEC coordinate
3. Time
4 & 5. Focus buttons (not used)
6 & 7.
and
DEC up and down drive buttons
8 & 9.
and
RA + and - drive buttons
These drive buttons are also used in Mode to select a Menu , to exit a
menu to get to a higher menu , and to adjust the parameters and .
10. The (-) button is used to select a slower slew speed and special
functions
11. The (+) button is used to select higher speed values and special
functions. It also displays the cursor under a parameter value and
also to accept the changed value (Execute or Return key).
There are 5 speeds: 0 (slowest) to 4 (fastest).
The handset always powers on at the slowest slew speed.
12. The “Mode” button toggles between the Navigation and Main Menus.
Press twice to enter or exit the Main Menu. It is also used to select
the most commonly used functions - see next page.
NOTES.
Arrows in the display indicate that in that direction there are more
menus or commands. Get there by the appropriate button.
There is a strong magnet at the rear of the hand unit for attaching it
to steel, but be careful of electronics that could be affected by the
magnetic field.
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HAG 24”RC v2.4 Sep 2016
Calibration.
Centre the eyepiece field of view on the reference star, adjusting the
pointing by using the
drive buttons. (Select slower slew
speed for final precise alignment)
Follow the procedure under “Main Menu” below to go to the “Objects”
menu, then the “Ref-Stars” menu and select the specific star in the list.
Select “Align1” from the object menu to calibrate the scope. To move to
another object, select it through the “Objects” menu and then select
“GoTo” from its menu.
Quick Function Selection
While in the Navigation Menu – RA and DEC plus Time are displayed and
the slew speed of the scope can be changed by pressing the (-) or (+)
buttons. The speed selected is shown briefly.
Main Menu
Press the “Mode” button twice (double click).
The Ref-Stars are named constellation abbreviation first, followed by the
first three letters of the Bayer (Greek) letter e.g. Rigel is “Ori Bet”.
When using “GoTo” the telescope moves to the selected object at maximum slew speed and the display returns to the Navigation Menu.
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HAG 24”RC v2.4 Sep 2016
The handset remembers the last menu position so it may be necessary to
return to the Main Menu (using the button) to access the required command.
Note that the telescope will always attempt to go to the object selected even if it is below the horizon. Always check that the scope is not
going to point below the horizon or bump into anything.
In an emergency the drive can be stopped by pressing any of the
direction keys on the hand controller or the red “Emergency Stop”
button on the drive controller. To reset power if the red button has
been pressed, twist the red button.
Lamp Function
Pressing the “Mode” button briefly, then the (-) button toggles the LEDs on
the back of the Handset on and off.
Display Lighting
Pressing the “Mode” button briefly then the (+) button toggles the display
LCD backlight on and off.
Profiles and System Menus
Do not use - These set various functions including Motor and Mount parameters.
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HAG 24”RC v2.4 Sep 2016
There is a copy of this page on the Control Desk






alpha
beta
gamma
delta
epsilon
zeta






Greek Letters
eta
 nu
theta
 xi
iota
 omicron
kappa
 pi
lambda
 rho
mu
 sigma
Named Stars
Adhara
CMa
Albireo
Cyg
Aldebaran
Tau
Alderamin
Cep
Algol
Per
Alioth
UMa
Almach
And
Alnilam
Ori
Alnitak
Ori
Alphard
Hya
Alpheratz
And
Altair
Aql
Antares
Sco
Arcturus
Boo
Bellatrix
Ori
Benetnasch
UMa
Betelgeuse
Ori
Capella
Aur
Castor
Gem
Deneb
Cyg
Denebola
Leo
Dubhe
UMa
Fomalhaut
PsA
Gemma
Hamal
Kaus Australis
Kochab
Markab
Merak
Mintaka
Mirach
Mirfak
Mizar
Phecda
Polaris
Pollux
Procyon
Ras Alhague
Regulus
Rigel
Scheat
Schedar
Sheliak
Sirius
Spica
Sulafat
Vega


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



















8






tau
upsilon
phi
chi
psi
omega
CrB
Ari
Sgr
UMi
Peg
UMa
Ori
And
Per
UMa
UMa
UMi
Gem
CMi
Oph
Leo
Ori
Peg
Cas
Lyr
CMa
Vir
Lyr
Lyr
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
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
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



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HAG 24”RC v2.4 Sep 2016
HAG 24" Telescope Reference Stars—Page 1
Constellation
Abbr. Stars
And    
Andromeda
Aqr   
Aquarius
Aquila
Aql      
Ara
Ara    
Aries
Ari  
Auriga
Aur      
Boötes
Boo      
CVn 
Canes Venatici
Canis Major
CMa      
Canis Minor
CMi  
Capricornus
Cap  
Carina
Car      
Cassiopeia
Cas      
Cen      
Centaurus
Cepheus
Cep     
Cetus
Cet      
Cir
Circinus

Columba
Col  
CrB 
Corona Borealis
Crv    
Corvus
Crux
Cru     
Cygnus
Cyg      
Dorado
Dor 
Draco
Dra      
Eridanus
Eri
   
Gem      
Gemini
Grus
Gru    
Hercules
Her      
Hydra
Hya      
Hydrus
Hyi   
9
 
 
   

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HAG 24”RC v2.4 Sep 2016
HAG 24" Telescope Reference Stars—Page 2
Constellation
Abbr. Stars
Ind 
Indus
Leo      
Leo
Lep    
Lepus
Lib   
Libra
Lup      
Lupus
Lyn 
Lynx
Lyr   
Lyra
Mus  
Musca
Ophiuchus
Oph      
Orion
Ori      
Pavo
Pav  
Peg      
Pegasus
Perseus
Per      
Phoenix
Phe   
Pic 
Pictor
PsA 
Piscis Austrinus
Pup      
Puppis
Reticulum
Ret 
Sagitta
Sge 
Sagittarius
Sgr      
Scorpius
Sco      
Serpens
Ser  
Taurus
Tau      
Tri
Triangulum
 
Triangulum Australe TrA   
Tuc 
Tucana
Ursa Major
UMa      
Ursa Minor
UMi   
Vel     
Vela
Virgo
Vir    
10


  
   



   
    
  
 
HAG 24”RC v2.4 Sep 2016
Notes:
HAG 24”RC v2.4 Sep 2016
24” Dome Controller MCU
(Microprocessor Control Unit)
11
HAG 24”RC v2.4 Sep 2016
24” DOME CONTROLLER
Do not use this controller when visitors are present in the dome to avoid
any potential danger of personal injury by sudden dome movement.
The 24-inch Dome Controller is a microprocessor based device offering
manual movement control, tracking and parking functions. It is based on a
Raspberry Pi 1 model B+ microcomputer and associated circuitry driven
by a computer program written in the language python.
The unit is housed in a tan coloured box hereafter referred to as the MCU
(microprocessor control unit). The design allows the processor to be easily
accessed for software updates if required.
Before its power is switched off, the on-board microprocessor MUST
be shut down properly or corruption of the operating program could
occur - see SHUTDOWN below.
USE
1.
Remove the dome chains and then switch on the dome power at
the wall switch.
2.
The dome rotation may be switched to Handset operation by moving
the Mode switch on the right hand side of the MCU towards the back.
This transfers control to the manual handset and disables all function
on the box which does not need to be powered on in this mode.
3.
If full functionality is required, switch on the mains power to the MCU.
This will power up the microprocessor and run the control program
automatically. This procedure will take about 30 seconds and when
ready the orange LED Ready light will illuminate.
4.
When the orange Ready light is on, the L/R direction switch selects
the direction of dome movement and the Direction LED will illuminate
red if left is selected, or green if right is selected. (See Notes at end).
5.
The dome may be moved by selecting the direction and pressing the
Move button. You may still use the manual handset by switching the
Mode switch but you will need to switch back to use the extra track or
park functions. If you wish to use the Park facility on shutdown, the
dome should not be moved past the home position by using the
handset.
6.
Whenever the dome is moved, always check for obstructions
and be ready to stop.
7.
When the dome is moving, either the Left (red) or Right (green) LED
will light.
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HAG 24”RC v2.4 Sep 2016
1.
TRACKING MODE.
In this mode the dome will move every few minutes for a few seconds
to line the shutter up with the telescope direction. The move and wait
periods are programmed into the MCU.
2.
To enable dome tracking, ensure that the shutter is aligned with the
telescope view and press the Track button.
 The first wait period will start and the green Right LED will flash to
indicate tracking is activated.
 After the wait period the dome will move during which the Right LED
will remain on and at the end of the move period the next wait period
will start (Right LED will resume flashing).
3.
During tracking be aware of any potential obstruction to dome
movement, e.g. ladders or people!
4.
To terminate tracking press and hold the Stop button until the green
Left LED stays off.
5.
PARKING MODE. (only use if the handset has not been used)
In this mode the dome will move to the home position.
 If it approaches the parked position moving to the left it will stop
when parked. If it approaches moving to the right it will overshoot,
pause and park moving to the left.
 This procedure ensures that any play in the gears is taken up and
the dome chains will align properly.
 Ensure the dome rotates in the correct direction to the park position,
if not press the Stop button and park the dome manually.
6.
Once the dome is parked, always turn off the Dome Controller
power switch on the dome wall before attaching the chains.
7.
SHUTDOWN.
The MCU MUST be shut down before removing mains power. Press
and hold the Shutdown switch on the left hand side of the MCU until
the Direction LED turns off. Then wait until the orange Ready LED
turns off. Wait a further 5 seconds and then the mains power to the
MCU should be switched off and it should be unplugged.
NOTES:
Dome rotation left and right are anti-clockwise and clockwise respectively.
Do not unplug any of the cables.
There are timing limits to prevent excessive dome rotation:
The time limit for tracking is 8 hours after which the dome will stop.
The time limit for a single move or park operation is 3 minutes after which
all the buttons will be locked until the stop button is pressed.
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HAG 24”RC v2.4 Sep 2016
This training booklet is copyright Hampshire Astronomical Group and is provided
to members for the purposes of training and guidance.