14
Latitude Adjustment for 1100GTO German Equatorial Mounts
The 1100 mount accommodates a latitude range from 0 to 78 degrees and 90 degrees. The Altitude Adjuster Bar allows
for gross latitude ranges, while the Adjustment Knob is used to provide the precision adjustments when polar aligning. The
Altitude Adjuster Bar is positioned into one of nine slots which provide an overlapping latitude range.
This altitude bar is very convenient when travelling to remote sites, as it allows you to transport your mount in the more
compact, zero-latitude position. You can change to your remote site’s latitude in one quick motion of the altitude bar.
How to change the position of the Altitude Adjuster Bar
1. Due to the portable size of the 1100GTO mount, this
procedure can be done with the mount fully assem-
bled, or can be made easier using only the R.A. axis.
However, DO NOT attempt to make these adjust-
ments with an instrument or counterweights mounted.
2. The mount’s Polar Axis is held in place between the
two side plates of the Polar Fork. The axis pivots on
custom shoulder bolts located towards the rear of
each side plate. These bolts should not be loosened
when making altitude changes to the mount.
3. Loosen all four Polar Axis Lock Knobs about 1 turn.
4. Tilt the R.A. axis upwards and hand tighten the lock
knobs so that the axis does not drop while you are
repositioning the Altitude Adjuster Bar.
5. Note that the Altitude Adjuster Knob is attached to a threaded rod that travels through the Altitude Adjuster Bar. Turn
the knob so that you see about half of the threaded rod protruding from both
sides of the bar. This will allow you to
move the mount fully within the altitude range. The slots are positioned at 9 degree increments and the threaded rod
has 10 degrees of travel. They represent the following altitudes:
a) Slot 1 - 0-10° center: 5°
b) Slot 2 - 10-20° center: 15°
c) Slot 3 - 19-29° center: 24°
d) Slot 4 - 28-38° center: 33°
e) Slot 5 - 37-47° center: 42°
f) Slot 6 - 46-56° center: 51°
g) Slot 7 - 55-65° center: 60°
h) Slot 8 - 64-74° center: 69°
i) Slot 9 - 73-78° Note - it is necessary to remove the
Polar Axis Lock Knobs and shift the mount into its 90°
position in order to utilize this upper slot. Once done,
lower the axis and restore the knobs.
6. Shift the Altitude Adjuster Bar into the correct slotted position. Note that the re-positioning is done so quickly and easily
that trial and error positioning is inconsequential. There is a degree scale on each Polar Fork with a corresponding
indicator line on the beveled edge of the worm wheel housing to assist you.
See photos above.
7. Note that the threaded rod has a rounded end. Also observe that the underside of the R.A. Axis has an inset socket.
When you loosen the Polar Axis Lock Knobs and lower the polar axis be sure that the rod comes to rest fully seated in
this socket. A little wiggle of the adjuster knob will ensure its proper seating.
8. Turn the Altitude Adjustment Knob to raise or lower the Polar Axis to your approximate observing latitude (note the
previously mentioned altitude lines on the side). Tighten the Polar Axis Lock Knobs with finger pressure only. You do
not need to tighten with the hex key.
Insert
Rod
Socket
Altitude Knob
Altitude
Slots
Altitude Adjuster Bar & Socket
1100GTO shown in photo
DO NOT Loosen
Pivot Bolt
Altitude
Adjuster
Position
Slots (9)
Altitude
Adjuster
Bar
Latitude
Degree Scale
Polar Axis
Lock
Knobs