Antenna Rotators: Channel Master CM–9521HD and RCA VH226F

tall antenna

Picture this scenario. You have a Yagi-style directional antenna such as a 1byone 85-Mile Outdoor HDTV antenna pointing at a cluster of TV stations to the south.

However, there are a few other stations scattered in different directions around you. You can’t get them because you’ve fixed the antenna in a certain direction.

You might capture some of these other stations by setting up a second directional antenna and combining the signals from both. However, you’d need to precisely aim the second antenna to optimize reception.

Alternatively, you could install a TV antenna rotator.

A rotator allows you to change the direction of your antenna without leaving the comfort of your couch.

In this article, I’m going to describe antenna rotators and how to set them up. But first, I’ll present the two leading TV rotator products on the market: the Channel Master CM-9521HD and the RCA VH226F.

Antenna Rotator Reviews

Side-by-Side Comparison


Channel Master CM-9521HD

Remote control: infrared

Remote control: infrared

4.1 x 4.1 x 10.6 in.

8.5 x 3.75 x 10.25 in.

Weight: 7.5 pounds

Weight: 5 pounds

Includes: mounting clamp

Includes: mounting clamp

Doesn't include: wire and rotator mast

Doesn't include: wire and rotator mast

Preset antenna locations: 12

Preset antenna locations: 69

RCA VH226F Review

The RCA rotator is enclosed in aluminium and has a sturdy design. The drive unit is easy to mount on a support pole with the included mounting clamps and U-bolts.

You can mount it on poles with a diameter of up to 2 inches.

What I like about this rotor is the fact that the drive unit is reliably waterproofed. Weatherproofing is an issue since it’s important to keep mechanical parts dry.

Weighing in at 5 pounds, the unit is lighter than its counterpart from Channel Master.

With this rotator you can program up to 12 antenna positions in memory.

This of course means more than 12 channels in total as you often get several channels from a given antenna position.

The control unit displays only two digits for azimuth headings, so for example, the heading 180 is represented as 18 on the control unit.

On the remote control, position memory is denoted by letters and not numbers.

The rotator doesn’t come with rotator cable so you’ll need to purchase this separately. Below in the installation section I talk more about how to set up and properly connect the rotator cable.

RCA advises that you leave no more than 3 feet separation between the drive unit and the antenna it’s turning.

Keep in mind that both this and the Channel Master rotator are light hardware units so you should secure them as tightly as possible against high winds.

The top of the drive unit will accommodate an antenna mast of up to 1.25 inches’ diameter.

The rotator should accommodate the largest antennas from RCA (though you don’t need to use an RCA antenna with this rotator).

RCA VH226F Manual

When evaluating a product for purchase, I always search for the instruction manual to understand the details.

Here you can find a link to the RCA VH226F Antenna Rotator Users Manual.

Channel Master CM-9521HD Review

The Channel Master rotator has a rugged TV antenna rotor and is durable. This model succeeds the earlier CM-9521A version.

As with the RCA rotator, this unit comes with mounting clamps and U-bolts for easy installation.

Unsurprisingly, it doesn’t come with a rotator cable or a mounting pole. Speaking of mounting poles, you can mount this rotator on poles with a diameter of up to 2 inches.

As for the cable, generic rotator wire is available online.

This rotator has a reputation for reliability over years of use. It’s also relatively quiet when it’s in operation.

The control unit’s memory accommodates up to 69 preset antenna locations. The control unit’s display shows azimuth headings as three digits.

Similar to the RCA rotator, when attaching an antenna above the drive unit, the manufacturer advises the antenna mast shouldn’t exceed 3 feet.

The rotator can accommodate an antenna mast of up to 1.375 inches’ diameter.

When installing the drive unit, it’ll need to face due north. This will allow the rotator to synchronize correctly with surrounding towers (see the installation section below).

Concerning the maximum weight the drive unit can bear, it should accommodate the heaviest Channel Master antennas, although you can use antennas from other manufacturers.

Channel Master CM-9521HD Manual

As with the RCA antenna rotator review above, I’m enclosing a link to the Channel Master CM-9521HD instruction sheet.

What is the Best Antenna Rotator?

Although both products have similarities, each offers certain advantages that may appeal to your situation.

Keep in mind that both these rotors are relatively lightweight products designed for turning your typical TV antenna and short mast — although some people use them for rotating larger items (such as Ham antennas or solar panels).

NOTE: If you're looking for higher performance, I'd suggest a more robust class of antenna rotators such as the Hy-Gain AR-40. You can also check if it's locally available.

Overall, the RCA offers good value for money for customers living in areas with a lower density of TV stations.

RCA rotators are dependable and built to last. Both the RCA and Channel Master products are comparable in terms of setup and installation.

I’d consider the Channel Master if I lived in an area with a greater number of TV stations. This rotator also has a reputation for having a motor and drive unit that can take a beating.

How Does an Antenna Rotator Work?

The way TV antenna rotators operate is simple. They typically have two main parts: there’s a drive unit with a motor inside that sits on the mast below the antenna and turns it.

Then there’s a control unit that’s near your TV. The control unit allows you to enter the heading towards which you want the antenna to face.

These days, antenna rotators come with a remote control allowing you to change the antenna’s position. The control will have left and right arrow buttons specifying in which direction to rotate the antenna — normally by one degree each time you click a button.

Remote controls bring convenience but must have a direct line of sight to the control unit.

Both the drive and control units are connected via a rotator cable that consists of three or four wires (e.g., red, black, and green).

These wires both power and convey information to the drive unit, as well as ground it.

3 wires

You should make sure this cable is securely and correctly attached to both devices since many troubleshooting issues arise from an improperly connected (or weatherproofed) cable.

Are There Wireless Antenna Rotators?

In standard rotators, both the control and drive units are wired. This means you must run a rotator cable through the house to connect them. Wouldn’t it be great to have a wireless or networked drive unit that would save you this trouble?

I’ve searched for such a rotator but haven’t found it yet. Let me know if you find one!

How to Operate a Rotator

Antenna rotators allow you to turn an antenna a full 360 degrees, orienting it towards the heading of any station in your area.

You can find azimuth headings for surrounding television towers by looking at your signal report (use the magnetic headings).

Here’s an example. On the radar plot below, let’s say your TV antenna is aimed at the group of stations due south.

Now you want to change the TV channel to the station in the northwest corner, RF channel 13 (on high VHF).

You would enter the station’s azimuth heading (328 degrees) in the rotator’s control unit to turn the antenna towards it.

How an antenna rotator works

Rotate an antenna by entering a station heading

It’s as simple as that. In fact, you can orient your antenna towards any of the stations on the plot.

Whether you receive those stations or not depends of course on their signal strength.

Pros and Cons of TV Antenna Rotators

By now you might be thinking antenna rotators are an awesome idea so everyone should get one.

There are caveats however. Below I list some benefits and disadvantages of antenna rotators.

Advantages of TV Antenna Rotators

  • Turns your antenna to pick up local stations in any direction
  • Simple and convenient to operate
  • An alternative to combining several antennas

Disadvantages of TV Antenna Rotators

  • Orients the antenna towards the same station for all connected televisions in a household
  • If recording using a DVR, you should ensure your antenna is already facing the station before recording
  • Not synchronized with your TV or other entertainment devices ⁠— e.g., you must scan for channels independently of the rotator

To Rotate or to Stack?

If any of these disadvantages is hard to overcome in your situation (e.g., different members of your household want to watch their own channels) then you may consider combining or stacking antennas.

How to Install a TV Antenna Rotator

You’ve reviewed the information above and decided to get an antenna rotator.

Below are generic steps to give you an idea of what’s needed and what’s involved in the installation.

Antenna Rotator Installation Checklist

  • Rotator cable: The thickness of this cable will vary depending on the length needed to connect the control and drive units. For cable runs up to 150 or 180 feet, you'll need 20 AWG wire. For greater distances, it'll require heavier gauge wire.
  • Support mast for the drive unit: This should be of the appropriate weight-bearing size. You'll need such a support mast if you're not mounting the drive unit inside a tower.
  • U-bolts and mounting clamps: For securing the antenna to the support mast. These will likely be supplied with the rotator.
  • Cable ties, electrical tape, or standoff insulators: These are for securing both the antenna coax and rotator cable.
  • Sealants (optional): You may need to apply a sealant (e.g., silicone caulk, waterproofing grease) to the drive unit and cables to weatherproof connections.
  • Thrust bearing and guy wires (optional): For extra support of the antenna mast.
  • Compass for orienting the antenna and drive unit, if necessary.
  • Screwdriver
  • Adjustable wrench

The above list only pertains to the antenna rotator. If you already have an antenna installed, you’ll be reinstalling it on top of the drive unit so you may also want to check out this article on how to install an outdoor antenna.

Installation Steps

How to install a TV antenna rotator

Final rotator setup (with preamplifier)


Step 1: Check the Surroundings of the Antenna

To stay on the safe side, make sure the place where you want to install the drive unit is sturdy enough to support the extra weight of both the support mast and drive unit.

For example, if your current antenna is installed on the side of your house, make sure the structure will support the additional weight.

Check also for surrounding power lines or similar hazards that may get caught in the mast when it rotates.

Step 2: Test the Antenna Rotator

Take the rotator out of the package and run a test before installing it.

Temporarily connect the rotator cable to both the control and drive units and synchronize the rotator.

You may have to cut the cable and strip the wires with a wire stripping tool to be able to attach them to the control and drive units.

Pay attention to how the units should be wired with the rotator cable (e.g., if there’s an ordering of the multicolored wires in the terminals).

Make sure the rotator is registering correct headings of surrounding stations during the synchronization.

When operating your rotor pause for a couple of seconds between changing rotation direction in order to give the motor time to stop. This will extend the life of your rotator.

Step 3: Mount the Support Mast with the Drive Unit

Set up the support mast for the drive unit and the antenna, and make sure this mast is secured properly.

Then mount the drive unit on top of the support mast using the U-bolts and clamps.

Some rotators require you to orient the drive unit in a certain direction, such as the Channel Master rotor, which you should point due north (this will show as zero degrees on the control unit).

Step 4: Install the Antenna and Its Mast

Insert the antenna mast into the top of the drive unit using the remaining U-bolts and clamps.

Make sure the antenna will get optimal reception, for example, by using a level tool to make sure the mast is vertical.

If you’re installing a rotator recommended in this article, ensure the length of the mast between the drive unit and the antenna doesn’t exceed 3 feet.

If you insert a longer mast, you risk creating excess inertia for the drive unit that may cause a mechanical failure.

Minimizing the length of the antenna mast is a way of prolonging the life of your rotator.

You can lengthen the antenna coax by using extra cable and crimping tools if necessary.

Make sure to leave sufficient length in the coax cable by looping it so that the antenna can be rotated a full 360 degrees without yanking the cable.

When attaching the antenna coaxial:

  • If it’s using 75-ohm coaxial cable (e.g., modern RG-6 coax) you can use electric tape or cable ties to secure it to the support mast
  • If it’s using 300-ohm twin-lead cable, attach it to the antenna and support mast using standoff insulators

Re-attach the rotator cable to the drive unit (if you had detached it after the test above). You can use electric tape or cable ties to secure it to both masts.

Step 5: Attach a Thrust Bearing and Guy Wires (Optional)

If your antenna mast requires extra stability (for example, if it’s over 5 feet tall), you might consider installing a thrust bearing (such as the UTB-105) with guy wires to the mast.

This should increase the installation’s wind resistance.

Step 6: Connect the Rotator Cable to the Control Unit

Run the rotator cable from the drive unit and mast down to the control unit in your home.

You can run the rotator cable along the same path as the antenna coaxial cable.

Keep in mind that if the distance between the control and drive units exceeds about 150 or 180 feet, you should be using rotator cable that’s heavier than 20 AWG.

Step 7: Synchronize Your Control Unit and Set Antenna Positions

Synchronizing a rotator involves running an automatic program on the control unit to rotate the antenna 360 degrees.

This serves to initialize the rotator. After synchronization you should verify that the drive unit had indeed turned full circle. You might have to run a synchronization more than once for the rotation to complete.

Next you’ll turn the rotator towards the headings of various stations around you and program these into the control unit’s memory.

You’ll use the remote control to rotate the antenna to known station headings and press the arrow buttons until you find the antenna orientation that gets the best results.

You’ll mark these positions by entering the coordinates into the control unit. Keep in mind that rotators are not synchronized with televisions so you’ll likely need to run a channel scan on the TV as well.

You should also be able to manually add channels that you find by rotating the antenna using the digital tuner of your TV or set-top box.

Modern ATSC-capable TVs should allow manual addition of channels.

After these steps, the rotator should function normally, which means you can change channels by using the remote control to turn the antenna.

Weatherproofing the Rotator

Regardless of how a new the rotator is, you should check the drive unit and cable connections to make sure these are waterproofed.

You should particularly verify the connections of the rotator cable wires in the drive unit (and possibly use some dielectric grease on these terminal connections).

The grommet through which the rotator cable passes on the drive unit is often vulnerable to moisture, so check if this properly seals around the rotator cable.

Grounding the Rotator

The grounding of your antenna and rotator is generally two separate tasks. One of the wires of the rotator cable serves as a grounding wire so you don’t need to take further steps to ground the drive unit.

Also, manufacturers generally advise you to unplug the rotator during thunderstorms.


Antenna rotators can add many more over-the-air channels to your TV guide, but you should be aware of certain limitations.

Rotators should be installed with care, as they are vulnerable to high winds and can buckle under excessive weight.

You should research your preparations well when setting up a rotator and consult product reviews online to know of any issues in advance.

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