Meade LXD 650 FREQ = 60.1 M, FREQ = 60.1M, Mode Three Clock/Calendar, B. FREQ Option, Description

- 17 -

the CDS knows no bounds — any celestial object, including comets, asteroids, etc., are easily found, provided accurate coordinate data has been entered.

To enter a new pointing position in Right Ascension and Declination, press and hold the GO TO key until a double beep is heard. A blinking cursor appears over the R.A. coordinate numbers. Using the numbers on the keypad, type in the new Right Ascension coordinate numbers. Then, press the ENTER key. The blinking cursor is now over the DEC coordinate numbers. Enter the new Declination coordinate numbers, then press the ENTER key. At this point the CDS slews to the new coordinate position.

When it is necessary to enter a negative Declination setting, move the blinking cursor over the + symbol with the W key and then press the NEXT key to get the - (minus) symbol, then move the blinking cursor to the first number with the E key and enter the new coordinate numbers. If there is are already at a minus (-) Declination setting, follow the same instructions as above but press the PREV key instead to get the + symbol.

3. MODE THREE: CLOCK/CALENDAR

The continuously operating clock and calendar is the heart of the CDS. At power up, the telescope’s accurate sidereal clock automatically performs orbital calculations of the planets, and figures the correct stellar precession for the CDS's superior pointing ability.

The CDS comes with a long-life lithium battery back-up, making it unnecessary to enter the local time and date every time the system is powered up, thus enhancing the user friendly aspects of the instrument.

To set the local time and date and to enter the correct GMT offset, refer to page 6, Entering the Local Time and Date.

The long-life lithium battery (Panasonic CR2032 3 volt or Duracell DL2032B) is stored behind the #1697 Control Panel, Fig. 5. See Appendix E (page 50) for battery replacement information.

4. MODE FOUR: TIMER/ FREQ

A. TIMER Option

The TIMER option is designed for accurately timing different observing or imaging tasks for up to twelve hours. Counting down to zero, in the hours, minutes, and seconds format, the CDS beeps to notify an observer that the time is up.

To set the TIMER, move the LCD arrow to TIMER= 00:00:00. Then press and hold the ENTER key to get the double beep tone and the blinking cursor. Enter the number of hours, minutes, and seconds that you require. If it is necessary to correct an error in entry, use the "E" and "W" keys to move the blinking cursor and then type in the correct information. After entry, press the ENTER key again. When you are ready to start the count-down, press the ENTER key once more. To pause the count-down press ENTER again, and then again to resume.

If an automatic 12 hour count-down is desired, press, but do not hold, the ENTER key. Then press ENTER to begin the count- down.

B. FREQ Option

The FREQ (Frequency) option allows a user to digitally adjust the tracking speeds (not slew speeds) of the CDS in tenths of a hertz

from 55.0 Hz to 65.0 Hz. With this option, it is possible to match virtually every celestial motion in the sky, including the King rate (for tracking objects within 20 degrees of the horizon). Some popular drive rate settings are:

Frequency Rate	Description	Notes
60.1 Hz Q	Sidereal rate;	Default rate at power
	Quartz setting	up. Gives sidereal
		frequency accuracy to
		+/-.005%, also Smart
		Drive training rate;
		Best for most
		astrophotography.
60.0 Hz	Solar and	Average rate for
	planetary rate	tracking planets;
		actual rates vary due
		to retrogrades,
		oppositions, etc.
57.9 Hz	Lunar rate	Best rate for tracking
		the Moon.

Note: It is best to train the Smart Drive in the 60.1 Hz Q setting (see SMART menu file on page 12). The Smart Drive gives periodic error corrections in all of the other frequency settings.

There are three menu file options in the FREQ option. To view or set the options, move the LCD arrow to FREQ= and press the ENTER key. At power up, the FREQ= default is the 60.1Hz Q setting. The quartz rate is precisely fixed and cannot be altered. To choose a rate other than the quartz setting, press the ENTER key to see 60.1 M (Display 29) and then again to see 60.1 M with the up and down LCD arrow (Display 30). These two options can adjust the tracking speeds. The adjustment techniques are described below:

FREQ = 60.1 M

Display 29

Display 29 shows the manual rate menu file option that can be adjusted by pressing and holding the ENTER key to get the double beep tone and the blinking cursor. Type in the new rate, then when finished, press the ENTER key again.

FREQ = 60.1M ↕

Display 30

Display 30 shows the menu file option allows you to step the drive tracking frequency setting in tenths of a hertz, by using the PREV and NEXT (up and down arrow) keys. This is a convenient feature if you are trying to match the precise speed of a planet, comet, or any other non-stellar object. To exit this option, press the MODE key.

5. MODE FIVE: KEYPAD OFF/ BRIGHTNESS ADJUST

In order to see very faint objects, it is sometimes necessary to either dim or completely turn off the Keypad red LED backlighting. To do so, press the MODE button until the display goes blank. This is the OFF option.

To set the Keypad brightness, press the ENTER button and adjust the brightness to your satisfaction with the PREV and NEXT keys. To exit, press the MODE key.