Simple question about elevation/latitude gauge

[nnx]

Hello experts,
I'm trying to install a Powertech motor with a 100cm dish. I have a simple point of confusion. When setting latitude/elevation, which point on the fastening nut needs to be aligned to the required position? Basically, the question is ... in the attached image, what is the correct reading? Is it 30 degrees because of point A or is it 20 degrees because of point B ?

Thanks!
nnx

[rainman]

Originally Posted by nnx

Hello experts,
I'm trying to install a Powertech motor with a 100cm dish. I have a simple point of confusion. When setting latitude/elevation, which point on the fastening nut needs to be aligned to the required position? Basically, the question is ... in the attached image, what is the correct reading? Is it 30 degrees because of point A or is it 20 degrees because of point B ?

Thanks!
nnx

point A is correct you are at 20 degrees.

[nnx]

Thanks rainman! I guess I have follow-up question too ... on a different dish, the nut on elevation scale doesn't have the straight-edge guide. In this case, do I just align the center of the nut?
Thanks again.

[gordom]

Originally Posted by nnx

point A is correct you are at 20 degrees

HELLO! What am I missing here. The question was "Is it 30 degrees because of point A or is it 20 degrees because of point B ?"

The answer "point A is correct you are at 20 degrees" does not relate to the question.

[nnx]

Haha...you are right gordom! I didn't notice that. I just read 'point A is correct' and ignored the rest of the sentence. Hmm..lets see if someone will confirm which one it is.

[Sadoun]

A is correct. There you have it :-)

[rainman]

Originally Posted by gordom

HELLO! What am I missing here. The question was "Is it 30 degrees because of point A or is it 20 degrees because of point B ?"

The answer "point A is correct you are at 20 degrees" does not relate to the question.

you are right it is 30 degrees was typing fast and it was a miss type on the 20 degrees it should have said 30.

[rainman]

Originally Posted by nnx

Thanks rainman! I guess I have follow-up question too ... on a different dish, the nut on elevation scale doesn't have the straight-edge guide. In this case, do I just align the center of the nut?
Thanks again.

yes if you don't have a guide go with the center of the bolt.

[lestrade]

So, the center of the bolt is the correct reading. However, the picture that the OP attached had the word "Latitiude" along the scale. Do we set it to our latitude, or to the elevation that we get from the googlemaps? (My elevation angle in New Orleans is 54 deg, while the latitude is 30 deg.
Second, related question, I know that the focus does not depend on the satellite being on the axis of dish. Is that angle something else that I have to add or subtract from the 54deg, or is that taken into account?
thanks to all.
JPL

[pmb1010]

The picture shown above is that of the latitude scale of a MOTOR (not a dish).
Therefore, the setting should be to the latitude of the area the motor is located.
If you are in New Orleans, 30 is the value.
And in this case, the bolt is NOT the positioner indicator. The metal part shown in "A" is the correct scale pointer.

The offset for the dish & motor all work together. If you had a prime focus dish the elevation would be right at 54.
An offset dish uses a calculation to create the dish elevation figure.

Hope this helps.

[lestrade]

Originally Posted by pmb1010

The offset for the dish & motor all work together. If you had a prime focus dish the elevation would be right at 54.
An offset dish uses a calculation to create the dish elevation figure.

Thanks. It all helps. btw, I *think* you are misusing the term "prime focus". In astronomical terms, all of these satellite dishes are prime focus. That's where the LNB sits. I would think it's correct to say that most dishes have an off-axis prime focus.

Getting back to your comment. In the last sentence, how do we find the calculation and/or the amount of offset? thanks again.

[pmb1010]

The offset isn't calculated. It's fixed into the dish by the manufacturer.

The calculation for the dish elevation angle depends on the motor used.
How to install an HH-Mount Motor? Applies to DG240-SM3D22-STABHH100-HH120-Motech-SG2100