Orion instruction manual Atlas EQ-G Dual-Axis Controller

What if you need to aim the telescope directly north, but at an object that is nearer to the horizon than Polaris? You can’t do it with the counterweights down as pictured in Figure 1. Again, you have to rotate the scope in right ascension so that the counterweight shaft is positioned horizontally. Then rotate the scope in declination so it points to where you want it near the horizon.

To point the telescope directly south, the counterweight shaft should again be horizontal. Then you simply rotate the scope on the declination axis until it points in the south direction.

To point the telescope to the east or west, or in other directions, you rotate the telescope on its right ascension and declina- tion axes. Depending on the altitude of the object you want to observe, the counterweight shaft will be oriented somewhere between vertical and horizontal.

Figure 9 illustrates how the telescope will look when pointed at the four cardinal directions: north (Figure 9a), south (Figure 9b), east (Figure 9c) and west (Figure 9d).

The key things to remember when pointing the telescope are that a) you only move it in right ascension and declination, not in azimuth or latitude (altitude), and b) the counterweight and shaft will not always appear as it does in Figure 1. In fact it almost never will!

7.The Atlas EQ-G Dual-Axis Controller

The Atlas EQ-G with dual-axis hand controller will track any celestial object as the Earth rotates. You can also use the con- troller’s directional buttons to center objects within your tele- scope’s finderscope or eyepiece. For imaging purposes, the controller provides several guide speed rates so a camera can be accurately guided during a long exposure.

Attaching the Dual-Axis Controller

The dual-axis controller has a cable with a large, serial con- nector (DB-9) on one end. Plug the serial connector into the jack on the faceplate of the mount (Figure 9.1). Use the captive screws to secure the serial connector in place.

The nylon hook-and-loop strips have been provided so the dual-axis hand controller can be placed in a convenient posi- tion on the mount when not in use. Place the “hooks” strip on the back of the dual-axis hand controller, and the “loops” strip on the mount in a convenient location. Make certain the loca- tion of the strip on the mount will not cause the dual-axis hand controller to interfere with the motions of the mount or tele- scope being used.

You can reduce the chances of getting your hand controller, power supply, or other cables tangled during use of the Atlas EQ-G by using the included wire clip. The clip also prevents mechanical strain on the cord when being used. The wireclip is adhesive backed for easy attachment to any convenient loca- tion on the mount.

Powering the Atlas EQ-G Mount

The Atlas EQ-G should be powered by a 12V DC power sup- ply (tip-positive) capable of producing continuous current with a minimum of 2 amps. We recommend using a portable rechargeable battery, like the Dynamo or Dynamo Pro avail- able from Orion.

If you are using a portable battery like the Orion Dynamo, use the supplied 12V DC power cable (male cigarette lighter plug on one end, standard 12V DC power plug on the other end) to connect the battery to the 12V DC power jack on the faceplate of the mount (Figure 9.1). Make sure the Dynamo’s power switch is in the “on” position after connecting.

Functions of the Dual-Axis Hand Controller

There are three main categories of control buttons on the dual- axis controller (Figure 9.2).

1.Speed buttons

2.Directional buttons

3.Set button

The dual-axis hand controller is equipped with a red LED light in each button to indicate operation. An individual button’s LED will illuminate when the button is pressed. If a button combina- tion is entered, all LEDs will illuminate to indicate a successful operation.

Speed Buttons

The three buttons located near the top of the dual-axis hand controller (Guide, Slow, and Fast) are used to set the slewing and guiding speed of the mount.

Directional Buttons

The directional buttons allow complete control of the mounted telescope’s position during slewing or tracking. The Left and Right directional buttons control movements about the right ascension (R.A.). axis. The Up and Down directional buttons control movements about the declination (Dec.) axis.

Set Button

The Set button is used to set the dual-axis hand controller to operate in either Northern or Southern hemisphere locations.

Note: The Go button is not used in normal operation of the dual-axis controller.

Tracking Objects with the Dual-Axis Hand Controller

In order for your Atlas EQ-G mount to accurately track celestial objects as they appear to migrate across the night sky, your mount must be properly polar aligned. For more details on polar alignment, please consult section 6 of this manual.

Once the power switch is turned on, the dual-axis controller begins to track by rotating the R.A. axis motor at the default (sidereal) rate. The Dec. axis motor will not rotate. As long as the mount has been properly polar aligned, it should not be necessary to adjust the Dec. axis for accurate tracking. If you notice a lack of tracking precision at the default (sidereal) rate,

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