Correct motor elevation

[Vorg]

I can print an angle meter with my cad program that can read the needed angle to better then .1 degrees. So I should be able to preset the motor angle nearly dead on.

But finding the correct number to use is a bit harder. I was able to find the lon/lat numbers that put the pointer within a couple offeet of the dish on the google map angle finders. But having checked several different ones, I keep coming up with different numbers. Two sites have mentioned a .6 degree offset needed.

Small offset issues
2) SET THE MOTOR AXIS ANGLE TO YOUR LATITUDE, OR MORE PRECISELY 0.6 DEG MORE THAN YOUR LATITUDE.

My Latitude = 32 degrees, 13.90 minutes North (32.23161°)

The numbes I have found:

. Rotor elevation: 90 - 32.23161 = 57.76839
. Dish declination: 5.241/Dish Elevation: 24.73 ?
---------------------------------------------------------------
Dish Setup Data
. Motor Latitude: 32.2°
. Declination Angle: 5.3°
. Dish Elevation: --°
. Elevation: 52.5°
---------------------------------------------------------------
Javascript for antenna lookangles calculations

Satellite Elevation Degrees: 52.524
Offset antenna tilt Degrees: 115.2
Declination Angle Degrees: -5.24
Polaraxsis angle Degrees: 57.13
Polaraxis correction angle Degrees: 0.635
Declination from horizontal plane Degrees: 51.89
Geometric Elevation
. Earth flattening accounted for Degrees: 38.32 (8.971)
Simple Elevation
. (No flattening or refraction) Degrees: 38.30 (8.962)
Atmospheric Refraction Degrees: 0.020 (0.096)

 

[turbosat]

vorg its normally what your latitude is at your site, for the motor angle (on the motor bracket) but the real world number may be slightly higher or lower than that. Set your dish's angle, and the motor bracket at the given number and see if you are able to lock onto your south satellite. The one closest to your longitude..

 

[Auric]

I think that by the time you tighten the bolts it wont be as precise as you like. Even if you remove the lock washers & use double flat washers, I don't think there is anyway to hold the tolerances you desire.

But it's your hobby and I might add to enjoy it the way you like:up

 

[Lak7]

Most Motor Brackets have 2 sets of Gages, one is marked "Elevation", and the other is marked "Latitude".
Latitude = Your Latitude
Elevation = 90 minus Your Latitude

When Setting up, I rely on Results vs. Numbers

 

[B.J.]

I can print an angle meter with my cad program that can read the needed angle to better then .1 degrees. So I should be able to preset the motor angle nearly dead on.

But finding the correct number to use is a bit harder. I was able to find the lon/lat numbers that put the pointer within a couple offeet of the dish on the google map angle finders. But having checked several different ones, I keep coming up with different numbers. Two sites have mentioned a .6 degree offset needed.



My Latitude = 32 degrees, 13.90 minutes North (32.23161°)

.....

Look at BJDISCALC2

Just enter your latitude and it gives you the declination and the "latitude" setting (the motor elevation should be 90 minus this number). This calculator isn't exact as it uses a couple approximations, but it is within ~0.1 deg, and is better than using your latitude and the conventional declination numbers, which will tend to make you off by that ~0.6 deg error caused by the fact that the declinations of the sats are not constant, but actually change across the arc.

I agree with the comment above that it usually isn't possible to set these angles to 0.1 deg precision, however my feeling is that it helps to know the precise number even if you're not likely to hit it exactly, particularly when you're likely to round off to the nearest whole number, and if your latitude is 32.23, you're likely to round off to 32, but if you know that you should be aiming for 32.89 you'll probably round off to 33, which will put you closer to the proper angle.

You can't really expect to be able to set both the declination and the motor elevation accurate enough to track the arc well just by the angles. Generally you have to set either the motor elevation or the declination as accurately as possible, then get the other value by peaking on your true south sat. With some dishes, it is easier or more accurate to set the declination, and with other dishes, it's easier or more accurate to set the motor elevation, so you'd really only use one of the two numbers, and get the other number by peaking on a sat.
With these small offset dishes, you can't really set the declination, so what you have to do is set the motor elevation, which for you is 32.9. Set that and never touch it again.

 

[Vorg]

Yea, I wasn't even looking at the dish bracket settings atm. Just focusing on presetting the rotor as close as possible so most of the adjusting would be at the dish. Trying to get it down to just 1 elevation setting as much as possible instead of 2.

 

[Tron]

I've always found that the actual motor latitude setting should be just a bit higher than your latitude for best results across the arc. YMMV...