4.Star Key: Gives the user access to the utility functions of the hand control, such as changing the direction of the arrow keys and backlash compensation.

5.Hand Control Slew Rate Indicator Lights: Displays the speed at which the telescope will move when each direction button is pressed.

Rate Button

Pressing the RATE key (3) allows you to instantly change the speed rate of the motors from high speed slew rate to precise centering rate or two speeds in between. Each rate corresponds to one of the indicator LED lights (5) on the hand control. From left to right, the corresponding speeds are as follows:

Rate

1For fine centering of objects in the eyepiece

2For scanning around for objects in the eyepiece

3For centering bright stars in the Star Pointer

4For slewing around the sky from object to object

The hand control has a "double button" feature that allows you to instantly speed up the motors without having to choose a speed rate. To use this feature, simply press the arrow button that corresponds to the direction that you want to move the telescope. While holding that button down, press the opposite directional button. This will increase the slew rate to approximately 1.5º per second (equal to the third rate on the hand control). This feature will only function if the telescope is currently set at a speed rate of 1 or 2.

Utility Features

The NexStar HC hand control comes with a Star function key that allows you to change certain parameters of the hand controls functions, such as the directional logic of the arrow keys, backlash compensation of the motor gears and azimuth tracking.

Direction Buttons: When looking at a star through an eyepiece or star diagonal, the direction that the star moves when the Up and Down arrow buttons are pressed will be reversed from when the same object is being centered in the Star Pointer Finderscope. For example, when a star is being centered in the telescope's eyepiece, it may appear to move upward when the down arrow button is pressed (and visa-versa) even though the telescope tube is actually moving downward. This is why it is convenient to be able to change the arrow button direction when switching from using the Star Pointer to the eyepiece. To reverse the direction of the Up and Down arrow buttons:

1.Press the STAR key on the hand control. The activation light (1) on the hand control will light up to indicate that the button has been pressed. When the button has been pressed, the four direction buttons (2) will be non-operational until the button is pressed again.

2.Press the RATE button on the hand control.

3.Press the STAR key on the hand control to activate the direction buttons.

Anti-backlash– All mechanical gears have a certain amount of backlash or "play" between the gears. This play is evident by how long it takes for a star to move in the eyepiece when the hand control arrow buttons are pressed (especially when changing directions). The NexStar's anti-backlash feature allows the user to compensate for backlash by having the hand control quickly rewind the motors just enough to eliminate the play between gears. The amount of compensation needed depends on the slewing rate selected; the slower the slewing rate the longer it will take for the star to appear to move in the eyepiece. To change the backlash compensation:

1.Press the STAR key on the hand control.

2.Use the Right and Left arrow keys to speed up or slow down the initial speed of the azimuth motors when the arrow buttons are pressed. For example, if it takes a star too long to move in the eyepiece when the hand control arrow buttons are pressed, then press the Right arrow button to speed up the initial motor speed. The buttons can be pressed repeatedly to increase the initial motor speed even more.

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Celestron NexStar HC manual Rate Button, Utility Features
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NexStar HC specifications

The Celestron NexStar Hand Controller (HC) is an advanced control unit designed to enhance the astronomical observation experience for both novice and experienced stargazers. This innovative device is an integral part of the NexStar telescope series and offers a range of features that simplify the process of locating celestial objects.

One of the main features of the NexStar HC is its user-friendly interface. The controller is equipped with a large, illuminated LCD screen that displays essential information clearly, even in low-light conditions. The layout is intuitive, allowing users to quickly familiarize themselves with its functions. The keypad includes dedicated buttons for common tasks, making it easy to navigate the expansive database of celestial objects.

The NexStar HC boasts an impressive database containing over 40,000 celestial objects, making it a powerful tool for astrophotography and observational astronomy. Users can access planets, stars, galaxies, and nebulae at the touch of a button. The built-in database allows for precise and efficient locating of objects, significantly reducing the time spent searching the night sky.

One of the standout technologies featured in the NexStar Hand Controller is the GoTo functionality. This advanced tracking technology enables the telescope to automatically locate and track celestial objects with high precision. By entering the desired object into the controller, users can allow the telescope to autonomously adjust its position, providing a hassle-free experience.

Additionally, the NexStar HC supports various alignment methods, including SkyAlign, AutoAlign, and One-Star Align. These alignment techniques assist in calibrating the telescope for optimal tracking and positioning. The SkyAlign method, in particular, allows users to point the telescope at any three bright stars, and the HC will calculate the telescope's location in relation to those stars, making alignment accessible even for beginners.

The NexStar Hand Controller is also compatible with Celestron’s StarSense technology, enabling automatic alignment using a smartphone. This feature allows users to refine their observations seamlessly and provides a modern twist to traditional stargazing methods.

Other notable characteristics include programmable go-to tracking speeds and the ability to save user-defined locations. The controller’s ergonomic design ensures comfort during long observing sessions, while the robust build quality guarantees durability.

In summary, the Celestron NexStar Hand Controller combines a wealth of features and cutting-edge technologies to enhance the stargazing experience. Its user-friendly interface, extensive database, versatile alignment methods, and compatibility with advanced tracking systems make it an indispensable tool for anyone looking to explore the wonders of the night sky.
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