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AUTOGUIDING


CAMERA GUIDING OF DRIVE SYSTEMS
Autoguiding can be done with almost any make of telescope provided it has handset buttons for the four directions North, South, East, West. This facility is used by AUTOGUIDERS such as those based on CCD imaging chips - SBIG or MEADE PICTOR types - when the handset buttons are pressed automatically by the electronics to counter image drift. To be of use, the adjustment speed provided by the handset when the button is pressed must be fine, between 5% and 100% of Sidereal rate. It is no good if the telescope will suddenly shoot off at ten times sidereal speed!

Autoguiding with AWR Microstep systems - just plug the 6 pin cable into the socket labelled CCD on the drivebox. Other AWR systems require a dongle to be fitted to provide the correct socket. This can be retrofitted to all our version handsets.

In the presence of RA backlash, which is unavoidable in most drives systems, the RA adjust rate must be less than the sidereal speed so the RA motor NEVER rotates backwards when the autoguider is correcting. This stops backlash on the RA axis happening at all. On DEC it is a different matter, the direction of the motor will be changing all the time if you have set up to adjust for very small corrections (less than 2 arc seconds). This is not a good idea as it will try and start following the Earth's atmospheric fluctuations. All it should try and do is cope with a gradual drift in DEC which is caused by either non-perfect polar alignment or refraction effects changing the apparent declination. Please consult the user groups for further advice and guidance on the use and setup of CCD cameras and autoguiding PC software.

In the presence of DEC backlash it is common for autoguiders to struggle as the DEC motor can constantly be changing direction and so spoil images. There is an easy way round this - bias the DEC drift in one direction only. This is achieved by deliberately offsetting the poler alignment. If you are observing near the meridian you need to offset the polar azimuth position. If you are observing at hour angle 6 hours then you need to offset the polar elevation.

Modern commercially made telescopes very often have a "CCD" input socket for an RJ12 6 pin connector. The CCD autoguider output would plug directly into this socket. Some autoguiders require opto-couplers to provide isolation and so a RELAY BOX is required. Such devices are manufactured by MEADE, SBIG and now AWR TECHNOLOGY. Our design uses solid state relays and can be supplied ready to wire into your handset, or fitted for you.

We have added AUTOGUIDER SOCKETS for the following handsets:
AWR HC20 VIXEN Skysensor
AWR HC200/300 VIXEN DMD-1
AWR SYS5/VIX SKYWATCHER EQ3-2
AWR SYSTEM 5 CELESTRON Nexstar Handset
There have been others . . . the details will appear when we have time to trawl through our records.

For older systems, home made etc, where there is no socket, AWR Technology can wire in an adapter to accept various autoguiders. The old SBIG ST4 provided four pairs of relay outputs (NORMALLY OPEN) which can be wired directly into the handset across the four direction switches. The OPT 2 on the price list is for a basic adapter and connector to suit. We now fit the standard 6 pin RJ12 input connector for this interface.

The modern standard for sutoguider inputs is one of active low inputs, that is a switch between the direction line and 0 Volts will turn on that direction button. All AWR autoguider sockets fitted comply to this standard. Some older handsets / drive systems use have the opposite interface (eg QEI 'Coordinate' drive system) where the inputs required are active high. This is most confusing but we have made a converter box for these models to bring it up to date and into line with the modern standard.

EXAMPLES OF INTERFACING for CCD AUTOGUIDING
Standard RJ12 to RJ12 lead 4.2 metres                                                12.00
Standard RJ12 to RJ12 lead 1.2 or 2.2 metres                                          8.00
ST4 15 pin D connector to 6 pin RJ12 lead with ACTIVE LOW signals                    20.00
RJ12 socket (SS2K CCD input format) converter lead to standard active low RJ12 lead  15.00
RJ12 socket (standard CCD input format) converter lead to SS2K lead 6 pin RJ12       15.00
RJ12 socket with isolation for ACTIVE LOW signals (dongle)to standard format lead    50.00
NEXSTAR HANDSET modified with CCD Input connector - See SEEKER                       85.00
The SEEKER                                                                           59.00
AUTOGUIDER TESTER for Camera and Drivebox                                            45.00
VIRTUAL ENCODER LIGHTS test box for AWR Systems                                      45.00
We can do any combinations of these, and also produce ACTIVE HIGH outputs so that whatever type of CCD soket you have for autoguiding, modern equipment can be made compatible.

NOTES:
RJ11 standard is 4 wires used in a 6 pin connector
RJ12 standard is 6 wires used in a 6 pin connector
RJ45 standard is 8 wires used in a 8 pin connector (Standard networking cable)

CONNECTIONS WITH COMPUTER GUIDING
There are many computer programmes that will now interface with a variety of cameras (including Wwbcams) that can produce autoguiding information. To connect this software to Telescope Drive Systems (any with the RJ12 standard input connector) requires an interface box "Parallel Port to RJ12" or "Serial Port to RJ12" or "USB to RJ12". These are relay boxes and manufactured by SHOESTRING ASTRONOMY or ASTRONOMISER. If you have the Intelligent Handset then you can also use ASTROART to guide through the handset serial cable with LX200 protocols.

DIAGNOSTIC TESTING OF AUTOGUIDER INTERFACES

To test the Telescope Drive AWR can supply two products - the SEEKER and the CCD SIMULATOR.
(1) THE SEEKER from AWR Technology produces spirals by remotely pressing buttons in a regular fashion by operating through the AUTOGUIDER INPUT socket on your drive system.. See
more information. This is a universal test product for many commercial telescope products having intelligence such as Meade, Celestron, Vixen Skysensor 2000 and Sphinx, Losmandy, Takahashi etc. If you get a spiral then your socket on the drive system is tested!.This product can be used with ANY AUTOGUIDER INPUT SOCKET ON ANY TELESCOPE TYPE provided it uses the 6 pin connector. PRICE ABOVE

(2) The CCD SIMULATION mode of the AUTOGUIDER TESTER has controls and lamps to tell if the autoguider input socket of your handset is active low or active high, It uses a battery for the lamps and the directions should operate when the controls are set. This is a more direct and comprehensive test of the autoguider socket on your drivebox than the SEEKER. This again is a universal tool for many commercial telescope makes. This product can tell you instantly if the drivebox is capable of accepting autoguider controls of the right polarity, and so is a big time saver. This product can be used with ANY AUTOGUIDER INPUT SOCKET ON ANY TELESCOPE TYPE provided it uses the 6 pin connector. MORE INFORMATION. PRICE ABOVE

(3) For AWR Intelligent Drive System product there is a further diagnostic tool which is of some use. This is a LIGHTS BOX where you can see the virtual encoder pulses and scope movement direction and so see the effect of exercising the autoguider input on the encoder pulses.

To check the autoguiding signals from the camera (or a COMPUTER Interface Box) are performing the CCD CAMERA TEST mode of the AUTOGUIDER TESTER can simulate a drivebox. This has a battery and lights and tells if the direction buttons have been pressed within the camera and if active low or active high signals are present. It purely indicates the state of the lines from the camera but is a rigorous test of its interface. This product can tell you instantly if the camera is giving out the correct autoguider controls of the right polarity, and so is a big time saver. MORE INFORMATION. PRICE ABOVE


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