Ever tried a tenna-rotor???

[sikma]

I know it wouldn't be as user friendly as a diseqc motor, but has anyone ever tried using an antenna rotor in place of a STAB or H-H? I would assume it would work in theory unless their motors aren't strong enough. (I'm just 'spit-balling' here)

 

[neil_kc1]

sikma i think the bigger problem would be elevation. Normally you initial elevation is for your true south satellite. and antenna rotor would just turn the dish toward the area but not shift the elevation like the diseqc motor does.

 

[PSB]

If you off-set your mast/pole to the same angle as your Latitude it may work (If motor is strong enough) I have done that many times, aim true south then as you move east and west it will follow the Clarke Belt exactly!

 

[voomvoom]

I use to use one for a polarotor. It's still on my dish. Now I have a servo motor to do the work. The servo motor works in the blink of an eye, while the rotor took a few seconds to turn 90 degrees. I also had a hand crank (simular to a crank on the front of a boat trailer) to move the dish east or west. Those were the days! But, like PSB says, it should/could work if it's strong enough.

Al

 

[N4ST]

Would be an interesting experiment. You would have to jerry-rig something to give you the correct inclination for your axis of rotation. I would imagine that the tenna-rotor has more slop in pointing accuracy/repeatability and does not have as fine of a step size for positioning. 5-10 degrees positioning is usually good enough for OTA TV, but won't cut it for the satellites.

 

[partyharty]

Dosent a motor also adjust for the skew of the dish?
Antenna rotor would not do this (and on a several of the sat's the wrong skew can make you miss the signal

 

[PSB]

If it rotates exactly around the latitude angle it will skew its self! (Declination angle)

I did this recently with my 40" P* dish but have been using this method for years to make a poor mans polar mount.


http://www.satelliteguys.us/showthread.php?t=39119

 

[partyharty]

Cool, I guess I need to dig out my old realistic antenna rotor. I was under the impression that it wouldnt track the skew to the satellites (so it was relegated to a "junk box".

Now I get to see if it's got enough umph to move the DirecPC Dish.

I will set it up like I did when we used it for our OTA anteanna (at another house). I took a paint marker and marked where each channel was located.

I love this site :>

 

[caddata]

In reference to a polar mount for a prime focus dish: The dish motor has no role in "tracking the Clark Belt", it only provides the motion necessary to move from one satellite to the next. Tracking the Clark Belt takes place thru the geometry of the polar mount. The adjustable axis of the mount (which may also be the axis ot the motor) points to Polaris (the North Star) A second adjustment (in addition to the axis) on the polar mount is the declination adjustment, which corrects for the latitude of the installation. Geometry of our offset dish motors allows for the "offset look angle" of our smaller dishes, but if you will notice the motor axis still points towards Polaris. Telescopes use a similar mount called an "equitorial mount", which allow timelapse photos of star movement.

As a side note: some of my first fabricated polar mounts (in the late 1970' and early 80's) which mounted 10 ft. fiberglass dishes used hollow round tubing as the axis. Alignment was acheived by looking thru the hole in the tubing (axis) at Polaris. This method of pointing the dish was called "Boresighting". Much more accurate than using a magnetic compass and tryiing to allow for magnetic deviation.

Thanks,
Harold