Antenna Rotator Overview (CM9521 CM9537)

A rotor or rotator is a mast-mounted, motor-driven device that permits the TV viewer to conveniently rotate (orient) the outdoor TV antenna in any direction. It is started and stopped by a manually operated control unit that is placed indoors near the TV set. A multi-conductor wire carries the power and control signals from the indoor control unit to the mast-mounted drive unit.

A rotor should be considered when the desired TV signals arrive at the receiving site from widely spaced directions that cannot be accommodated by the relatively narrow beamwidth of a single, fixed-position antenna. With a rotor, a viewer can conveniently orient the antenna in the direction of the desired channel’s transmitting tower, or in the direction that provides optimum reception of a particular channel. A rotor also permits convenient “fine tuning” of the antenna direction to compensate for variations in signal direction caused by changing atmospheric conditions or other signal-distracting conditions. Additionally, the rotor permits elimination of adjacent-channel and other types of interference that in some cases can be solved by slight reorientation of the antenna.

Automatic Rotors

The control unit of the automatic type rotor has a direction-calibrated knob, dial, or digital display.  When this knob is turned to the desired compass direction, the drive unit automatically turns the antenna to that direction and then stops it.

Installing the Rotor

To install a rotor, first assemble the antenna and attach it to a short section of mast. (This short mast section later will be installed in the top part of the drive unit.) If the antenna is large and has boom braces, the short mast section must be long enough to accommodate the boom braces and possibly a rotor alignment sleeve. A 3-1/2 foot section should be long enough. Use a shorter section if the antenna is small.

Attach the transmission line to the antenna, and set aside the antenna and mast.

Remove the bottom (or access plate) of the drive unit housing and attach the rotor wire. (Rotor wire is available in many different styles; however, the most practical and economical kind has only three conductors. An example is Channel Master Rotor Wire Model No. 9554.) All Channel Master antenna rotors use 3 conductor rotor wire. To attach the rotor wire to the drive unit, first strip back the insulation on all conductors and solidly twist together the wire strands that make up each conductor. Be sure there are no loose strands; they may impair the performance of, or short out the rotor. Use connecting lugs to attach the wires to the rotor terminals.

Most rotor wire will be color coded.  With color coded wires, attach the green wire to terminal No. 1, the Black wire to terminal No. 2, and the red wire to terminal No. 3.  For non-color coded rotor wire, the “reference wire” is either wider or is a different color than the other conductors. Connect it to terminal No. 1. Connect the middle wire to terminal No. 2, and the third wire to terminal No. 3. If you use four or five-conductor wire, attach the third, fourth, and fifth wires to terminal No. 3.

The wires must not touch each other or the housing after they are connected. Cover each connection with an insulating material to prevent corrosion and rusting. Then reinstall the bottom (or access plate) of the housing.


Installation instructions for CM9521A Rotator system.
Prior to installing the system, connect the system with a short cable and familiarize your self with its operation. (This can also be done if the system has already been installed.)
Connect the controller to the rotator. (The Terminal numbers, 1, 2, 3, are printed on the circuit board of the rotator connector board and on the back of the controller)
Turn on the power to the controller.
Please press the sync button on the controller and let it complete the cycle. It should move or hum for about 1 minute. 
After that completes, input 000 with your remote. Once completed, this will have the rotator set up for facing North. 
Unplug the power from the controller for about 10 seconds. 
Plug the power back in to the Controller. It should immediately read out H60, HH1, and then 000. It will then turn off.

Now when you install the rotator, the Arrow on the top portion of the rotator should be facing north and the lower mast stop on the rear of the rotator base should point South. (The rotator base should be on the North side of your lower mast.)

Now you can mount your antenna to the upper mast and point it North. 
Note; the upper mast can be no longer than 3'. Shorter is recommended.

Testing Voltage on CM9521 System
• Measure using your AC Voltage mode on your Voltmeter. 
o Readings could vary, but likely within ~15%
• Measure while all 3 wires are connected properly from controller to rotator.
o Connector #1 to connector #1, 2 to 2, 3 to 3
• Probes to pins 1 & 2
o ~26Vac while pressing the “UP” button on the remote.
o ~26Vac while pressing the “Down” button on the remote.
o ~ 0Vac while no buttons pressed on your remote. (If the controller is not counting/rotator not moving)
• Probes to pins 1 & 3
o ~17Vac while pressing the “UP” button on the remote.
o ~17Vac while pressing the “Down” button on the remote.
o ~ 0Vac while no buttons pressed on your remote. (If the controller is not counting/rotator not moving)
• Probes to pins 2 & 3
o ~17Vac while pressing the “UP” button on the remote.
o ~17Vac while pressing the “Down” button on the remote.
o ~ 0Vac while no buttons pressed on your remote. (If the controller is not counting/rotator not moving)

Symptoms if wires are connected incorrectly.
• #1 and #2 are reversed, 
o The rotator will run backwards 
• #2 & #3 are reversed, 
o The unit MAY run backwards when “UP” arrow is pressed, but was slow, low voltage.
o The down button did not get a reaction except for buzzing motor. Low voltage.
• #1 and #3 are reversed, “down arrow is pressed and it MAY run backwards, slowly, low voltage. 
o The ”Up Arrow” may make the motor buzz but did not provide enough voltage to move it.

Nominal resistance of total length of wire and motor winding's. 
Disconnect the rotator wires from the controller.
This will vary with wire gauge and length of wire. 
1 & 2 Aprox 6Ω to 10Ω (With short wire, ~6.5Ω)
2 & 3 Aprox 3Ω to 6Ω (With short wire, ~3.5Ω)
1 & 3 Aprox 3Ω to 6Ω (With short wire, ~3.5Ω)

If you are setting up "Preset Positions", please follow the instructions below.

Prior to setting the presets;
1. Set the rotator controller with your remote control to 000. (North)
2. Press the sync button on the front of the controller (Black button between the Digital Display and the V Down arrow) and let it count down to finish the sync cycle.
3. Now you can set your antenna position "Channel Presets".

To Setup Channel Presets; (We’ll use channel 12 for this tutorial.)
1. Adjust your antenna for the best reception for channel 12 
a. Use the Up and Down buttons on your remote control until you find the best reception for that channel.
b. The compass number will read out on the controller display. (We’ll say 165 degrees)
2. You can program the controller to use the “channel number” instead of the compass number.
a. The controller display is reading out 165.
b. Using the remote control, enter quickly, 1, 2, /\, 1, 2.
i. That’s 12, UP, 12.
c. The display will now read out “c12”
d. To get the antenna to point to 165 degrees to watch channel 12, use the CM9521A remote control and press 1 then 2. (not 012) 
i. The antenna will now rotate until it gets to 165 degrees.
e. The antenna is now in position to watch channel 12.
f. Conditions can change so you may need to fine tune the position by using the V and /\ buttons, (down and up buttons) for the best signal reception.

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