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Reviews Categories | Antenna Rotators & Accessories | Gemini OR-360 Help


Reviews Summary for Gemini OR-360
Gemini OR-360 Reviews: 2 Average rating: 3.5/5 MSRP: $$45.00
Description: The Gemini OR-360 "Orbit 360" is a 5-wire light-duty antenna rotator.
Product is in production.
More info: http://www.gemini-usa.com/
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K4TB Rating: 3/5 Feb 1, 2007 18:54 Send this review to a friend
Can Work as an Elevation Rotator  Time owned: more than 12 months
Because it allows a boom to be put all the way through it, I mounted mine as an elevation rotator for my yagis and BBQ grill dish for satellite chasing. It does a good job moving the two 10' boom yagis and the dish without any stalling or overshoot. The control box was not suitable to providing a clear indication of elevation angle, so I constructed my own box with a Radio Shack 12v supply, a voltmeter calibrated to read elevation degrees, and some switches, relays and other parts. I can now toggle up and down a little at a time by just depressing the proper switch.

After a few years the feedback pot in the rotator becme worn, so there is some jerkiness and instability in the position readout voltmeter when the rotator stops at certain points, but the antennas stay still. This is not really a problem except on very hot days, which we have often in Florida unfortunately. The wiper strip in the pot apparently warps from the heat. A metal "sun umbrella" helped but didn't cure the problem totally. Taking the setup apart to replace the pot isn't worth the work; when I take it apart I will install a rotator like the Yaesu G-5500.

I did buy one more of these as they were being phased out and I will probably use it to build a portable satellite antenna system. The Gemini OR-360 is nice to work with for homebrew antenna projects.
 
N5NSL Rating: 4/5 Jun 6, 2004 02:09 Send this review to a friend
Good Light Duty Rotator  Time owned: more than 12 months
The Gemini "Orbit 360" model OR-360 is a 5-wire continuous potentiometer-feedback rotator.
I bought the Gemini OR-360 "Orbit 360" at a Wal-Mart sale several years ago and placed it into service with a variety of directional antennas. At this writing the OR-360 aims a satellite dish fairly well. The rotator is apparently no longer sold from the manufacturer, but used units are still available.


The Good:

The Gemini "Orbit 360" is a fairly strong rotator with continuous analog-potentiometer feedback and is accurate to within three to four degrees. The DC motor and has strong enough torque to break ice and rotate a large VHF/UHF antenna under strong wind loads and icy conditions.. I've used it for a variety of directional antennas over the years without problems. The rotator has been very reliable over the years and due to the feedback potentiometers remains accurate without needing periodic rotate-to-end recalibration. The antenna mast-mounted gearbox assembly allows the antenna mast to mount through the rotator gearbox instead of just sitting on top of the gearbox on a mast mount platform like the common 3-wire rotator design sold through Channel Master, GE, and Radio Shack. The gearbox has about 1/10 degree antenna mast play into the reduction gears and effectively locks the antenna to direction when the motor is not running.

The control unit has a large, single, inset rotary knob where the direction of the rotator can be set by simply rotating the knob to the heading the user desires. A red activity light glows to indicate the rotator is running, and remains dark when the rotator is unpowered (either no power or rotator heading agrees with the control unit knob).

Both the rotator unit and the control unit has five tap screws intended for either bare wire or spade lugs. The electrical connection screw terminals on the control unit are located on its backplane while the screws on the rotator are located underneath the rotator behind a small hinged metal panel. The rotator also has a lower profile than many other rotator designs due to the through-the-rotator mast mount, enabling the antenna/rotator assembly to have a lower profile and additional antenna or counterbalancing elements to be mounted below the rotator gearbox. Although I referred to the rotator as light-duty, the motor and gearbox are quite strong and outputs a lot of torque. I was unable to stall the rotator with all my strength and bare hands. The rotator comes with two U-bolts and four brackets, two brackets for the U-bolts and two brackets to mate with the rotator casing-integral mast mounting bolts. The case is single-piece cast aluminum, the antenna mast barrel is another single piece of cast aluminum.


The Interesting:

The rotator control unit is AC powered, but only consumes 7 watts in operation (and 2 watts idle) allowing easy battery operation through a small AC inverter. The control unit itself has a single knob which rotates through 270 degrees to aim the antenna through 360 degrees. South is mentioned twice 120 degrees either direction from North and West and East are 60 degrees from North. The potentiometer feedback circuit constantly maintains control unit / rotator unit sync without any need to periodically rotate-to-end recalibrate, but has a hysteresis mannerism which causes the rotator to "jump" by about two degrees as one very slowly turns the direction knob.


The Bad:

The rotator is actually excellent, but as nothing is perfect, these are mild "bads".

The gearbox is moderately noisy when used in a small room under high torque but when outside is audible up to around 12 to 15 feet away when under torque load. When not under torque load the rotator is very quiet.

The rotator does not have a brake, but cannot be turned by hand from the antenna mast due to the gear reduction geometry. When the motor is at full-speed and reaches the heading indicated on the control unit, the motor and gearbox spin-down inertia carries the antenna mast an additional one to two degrees.

Another arguable bad is the rotator no longer seems to be in production--it's a pretty good design.


Conclusion:

The Gemini OR-360 is a pretty good rotator where you can find one and where the unit in question hasn't been damaged or worn out through very heavy use.
 


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