Meade ETX-105EC Standard Tripod Leg ETX-90EC, High-Latitude Tripod Leg ETX-90EC, Dec. at

LO	HI
22°		33°
23°
		34°
24°
		35°
		36°

There are two mounting methods available to polar align the telescope depending on whether you use the optional #883 Deluxe Field Tripod or a table tripod (specific to your model of ETX telescope).

To polar align using the #883 Deluxe Field Tripod (Fig. 17), follow the instructions provided with the tripod. To polar align using the #880 (ETX-90EC) or #881 Table Tripod (ETX-105EC or ETX–125EC, Fig. 16), use the following procedure.

1.Make sure the viewfinder is aligned with your ETX telescope (see ALIGNING THE VIEWFINDER, page 10).

Little Dipper

Polaris

Big Dipper

Cassiopeia

Fig. 14: Locating Polaris.

25°	37°
26°	38°
27°	39°
	40°
28°
	41°
29°
30°
	42°
	43°
31°		44°
32°		45°
33°		46°

2.Remove the two hole covers (12, Fig. 1) from the side of the drive base and thread the two identical fixed legs (4, Fig. 16) into these holes to a firm feel only.

3.Determine the latitude of the observing location from a road map, atlas, or the Latitude Chart for Major Cities of the World, page 27; determining the latitude within about one degree is sufficient.

4.Each table tripod is equipped with two adjustable tripod legs, only one of which will be used: The standard tripod leg is used at observing latitudes as shown in step 5 and has a dual latitude label attached (Fig. 15). The high-latitude tripod leg is shorter and is used at higher observing latitudes.

5.Locate the two mounting holes on the bottom of the telescope drive base. Mount the appropriate adjustable tripod leg to the drive base using the following latitudes:

Standard Tripod Leg (ETX-90EC)

32.5° to 48.5° uses high-latitudehole (2, Fig. 16). 22° to 35.5° uses alternate hole (3, Fig. 16).

High-Latitude Tripod Leg (ETX-90EC)

56° to 66° uses high-latitudehole. 44° to 55° uses alternate hole.

Standard Tripod Leg (ETX-105EC, ETX-125EC)

33.5° to 49.5° uses high-latitudehole. 23.25° to 36.5° uses alternate hole.

High-Latitude Tripod Leg (ETX-105EC, ETX-125EC)

56.6° to 67° uses high-latitudehole. 44.5° to 56.5° uses alternate hole.

Thread the appropriate leg into the required hole to a firm feel only. Set aside the tripod leg that is not to be used.

6.A small thumbscrew (6, Fig. 16) is attached to both the standard and high-latitude tripod legs. Loosening the thumbscrew allows the outer section of the leg to slide over the inner section, so that the leg can be extended. If using the standard tripod leg, extend the leg so that the center of the thumbscrew head aligns with the latitude of the observing location on the scale. Retighten the thumbscrew to a firm feel. (If using the high-latitude tripod leg, complete the adjustment of the leg extension in step 9.)

34°	47°
35°
	48°

Fig. 15:

Example of

Standard Tripod

Leg Latitude

Scales.

Example: The latitude of New York City is 41°. The tripod leg should be extended so that the center of the thumbscrew is set next to the 41° reading on the scale.

Note: With the standard tripod leg threaded into the appropriate hole in the drive base, the latitude scale may be at an inconvenient position for reading (e.g., the scale faces the drive base). This situation can be remedied by unthreading the leg, removing the thumbscrew, rotating the inner leg 180°, then reinserting the thumbscrew. The scale will now be readable when threaded back into the telescope base.

7.Loosen the vertical and horizontal locks (6 and 9, Fig. 1) and rotate the telescope so that it is oriented as shown in Fig. 16. Tighten the vertical

7

2 8

5 1

Dec. at 90°

	3
4	6

Fig. 16: Example of Polar Alignment Using the #880 Table Tripod and ETX-90EC. (1) Standard tripod leg with latitude scale; (2) High-latitude hole; (3) Alternate hole; (4) Fixed tripod legs; (5) Declination pointer; (6) Thumbscrew;

(7) R.A. scale pointer; (8) #1422 low-latitude balance weight.

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