ROTATOR CONSTRUCTION
(Refer to Figures 12)
TROUBLESHOOTING
1.
Outer Housing: The upper mast support (Bell)
and the brake housing are cast aluminum. The
upper mast support is secured to the brake
housing by four #12-24 x 3/4" self-tapping hex
head screws.
2. Position Sensor: The position sensing potentiome-
ter is located in the top of the bell casting.
3. Drive: A low voltage AC motor and its associated
gears drive the output ring gear at about 1 RPM.
The ring gear in turn is mechanically
interlocked in the upper mast support (Bell).
4. Brake: The brake is a disc type which is an
integral part of the motor armature. When power
is applied to the motor, the armature lifts pulling
the two disc pads apart which allows the gear
train to operate freely. With no power applied,
the weight of the motor armature forces the two
brake pads together which in turn brakes the
rotator.
5. Rotation Limits: Activated by the stop arm are
two electrical end of rotation switches which dis-
connect the motor power just before the rotating
bell housing reaches its full CW (0°) or CCW
(360°) positions.
6. Bearings: Two rows of ball bearings are provided.
Lubricate sparingly with factory approved
special low temperature grease. This grease
allow normal operation to -30°F (-34°C).
CAUTION
This unit has been thoroughly tested and cycled
before shipment. Follow the terminal board
wiring carefully between Rotator and Control
Box. Incorrect wiring will burn out the rotator
potentiometer and void the warranty.
Be sure Rotator and Control Units are compat-
ible. Do not intermix models with different oper-
ating voltages. This results in sluggish or non-
operating performance, burned out motors,
overheated transformers and burned out rotator
potentiometers, etc.
Most operational difficulties with rotators are
traceable to broken, shorted or grounded wires
usually at the terminal strips. Time spent in cutting
the leads to exact lengths, tinning, forming and
wrapping around terminals, cutting insulation to
exact lengths, and clamping to prevent strain on any
MECHANICAL PLAY
Frequently, the slight motion of the antenna array in
gusts of wind is due more to the natural flexing of
the elements and mast than it is due to actual play in
the rotator mechanism. A slight amount of "play" is
built into the rotator to avoid binding due to
environmental changes.
ANTENNA ROTATES IN HEAVY WIND
This is usually a matter of the mast slipping in the
support. If "slipping" or "turning" is suspected,
return the rotator to the end of rotation and visually
check to be sure that the antenna is in the original
stop location as installed. Check the nuts on the U-
bolts to insure that they are tight.
LACK OF POWER
If the antenna rotation is slow or sluggish or hard to
start, check for proper voltages. If the voltages are
correct, the 140 MFD motor start capacitor could be
at fault. It is recommended that a new capacitor be
tried before any other action is taken. If the electrical
circuit is okay, then check for. mechanical binding.
Pay particular attention to bearings and alignment of
the shaft on an inside tower mount. On any inside
tower installation, care must be exercised to get the
top mast shimmed to the exact rotational center of
the rotator upper mast support. If temperatures are at
-30°F (34°C) or lower, operation will be slow or
sluggish. This is normal!
