--
. .-- . .p'
-30-
The above procedure results in very accurate polar align-
ment, and minimizes the need for tracking corrections
during astrophotography.
POLAR ALIGNMENT AT LOW LATITUDES
The Meade equatorial wedge germits polar alignment in a
latitude range of 110 to 64. However, the wedge and field
tripod may still be employed at latitudes within! 100 of the
Earth's ~quator. In this latitude range the latitude fine-
adjust mechanism(s) of the wedge should be removed. By so
doing, latitude angle settings to 00 may be achieved.
ELECTRIC MOTOR DRIVE
Supplied as standard equipment with the Models 2080 and 2120
is an extremely accurate worm gear drive system, operating
from a 115 volt/60Hz synchronous electric motor. (Foreign
models may include a 220v-240v/50Hz motor; drives for Southern
Hemisphere operation are reversed in direction from their
Northern Hemisphere counterparts.) The power cord for the
Models 2080 and 2120 plugs into the bottom of the telescope's
drive base, through apertures in the wedge mounting plate (or
the table tripod for the Model 2080). See Figs. 10 and 11.
CAUTION: If an extension cord is required for your opera-
tion of the telescope, be sure that it is of the 3-prong
type. Do not defeat the safety purpose of the supplied
3-prong ~ord by using a 2-prong extension cord or 2-prong
adapter plug.
with the telescope set up in the equatorial mode (accomplish-
ed with the wedge/field tripod combination), plug the powe~
cord into a power outlet. Immediately, if you put-your ear
to the drive base of the telescope, you will be able to hear
the low-level noise created by the running motor. The drive
system turns the fork mount of the telescope through one
complete revolution every 24 hours, and results in the stars
"standing still" as you view them through the telescope eye-
piece. The motor drive also drives the R.A. setting circle,
as described in the next section.
The motion of the telescope caused by the drive system is
not obvious if you look at the telescope (in fact, it is not
even perceptible), but while observing through the telescope,
it is a very significant motion indeed. To check this point,
with a star centered in the telescope field and the electric
motor drive running, unplug the power cord: the star will
immediately begin to drift out of the field of view; at high-
er powers the effect is even more pronounced.
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