Retrofit My Radioshack Dish Onto My KTI Mount

[a33]

The one thing I need to make clear is, setting the elevation at 48.9 at the mount then double checking at the face of the dish with a 2x4 will assure that I have the proper declination automatically ? Or will I have to then make a declination adjustment ?

You have to set two things:
1. The angle of the rotation axis of the mount.
2. The angle of the dish to the rotation axis, called the declination offset angle. But the easiest way to set this (when the axis angle is already set properly) is by setting the total dish elevation (towards the vertical or horizontal).

A33

Edit. Ah! Primestar also posted already!

 

[JFOK]

Mike and A33,

This is where I got confused.
I thought the total degree of elevation was to be 48.9 which would then help with the declination.
So I keep the total dish elevation at 42.65 and try to add 5.85 to get the proper declination. This is where my issue arises. I don’t have enough declination bolt to make it to 48.9. My dish has to go upwards to get this reading. I will have to lengthen the rod to get this elevation.
Thanks to both of you for being so patient.

John

 

[a33]

I suggest you take a picture from the side, so that we can see the present elevation of the axis, and of the present total dish elevation, and of course a part of the pole so that we can see what is 'level' on the photo.

A picture speaks more than a thousand words.....

Am I right that your declination bolt is at the bottom of the ring?

greetz,
A33

 

[JFOK]

A33,

I’m at work right now. When I get home I’ll take some pics of my setup.
Yes the bolt is at the bottom of the ring.

John

 

[JFOK]

A33,

Here is the picture you requested.
Also a picture of my declination bolt "bottomed out."
Thanks in advance for your help.

John

 

[a33]

So, can you measure what the angle is at the white line?
It should be 47.35 against the vertical, but it looks like just 32 degrees now. Though the view of the photo is from an angle, so it will be a bit bigger I guess.

 

[JFOK]

A33,

The angle for that white bar is 42 degrees.
Thanks for your help.

John

 

[a33]

Well, I put the white line along the rotation axis of the mount.
The elevation there should be 47.35 degrees, not 42 degrees.
It should be facing the sky more.

Can you change that angle to 47.35 degrees, so more facing the sky?

A33

 

[JFOK]

A33,

Yes I can raise it higher...plenty of room on that bolt. Will do so tomorrow, have some evening business to attend to.
Thanks so much.

John

 

[a33]

OK, no hurry. But that is the first step now.

After that, check that the dish is exactly in "zero-position", aligned with the mount's axis.
You can do that by checking that the distance from left side of the dish to left back side of the mount, equals that same distance on the right side.
If not, move the dish with the actuator, till left and right distances are equal.

After that, please take a photo again from the side, showing the present angles; to continue to the next step.

Greetz,
A33

 

[JFOK]

A33,

I corrected the level of degree on the mount to 47.4 and then moved the dish to the the zero position as requested.
See picture.

Thanks,

John

 

[Titanium]

It would be easier to estimate the elevation and declination if two photos were taken.

1. A close-up of only the mount and ring. Taken from the side at level with the mount.
2. Stand further back to show the whole reflector and align the shot so the dish edges line-up.

 

[a33]

I corrected the level of degree on the mount to 47.4 and then moved the dish to the the zero position as requested.
See picture.

OK, good work.
When I try to assess the angle from the picture, it looks like about 42 degrees towards the vertical, so 47 degrees towards the horizontal.

To check if the present elevation angle is 47.4 or 42.6 degrees, could you do this experiment?

1. Hold the inclinometer at the axis, so that it shows the 47.4 you measured (so in your photo, at the right side of the axis).

2. Now shift the UPside of the inclinometer a bit away from the axis (so in your photo: a bit more to the right).
(The lower side of the inclinometer stays at the axis.)

3. Read again the value of the inclinometer in this position: is the value HIGHER or LOWER than 47.4?


It seems all indeed to be a matter of confusing angles, I think now. And I think we will get there!
The good news is: From your last picture, it shows that the dishring and axis are about parallel. That means that the bolt for the declination is now extended more than will be needed. So: it will be long enough.

greetz,
A33

Edit: added the word "ring".

 

[a33]

BTW.
If you have an inclinometer showing an arc of degrees, there is another way to check what I wrote in the post above:

1. Set your inclinometer on the axis, showing the 47.4 you measured.

2. Take a picture showing the inclinometer on the axis. Part of the axis should be seen on the photo, and also the numbers on the inclinometer should be a bit readable.


(That way we can do the experiment, above, in an imaginary way.)

Greetz,
A33

 

[JFOK]

A33,

When I tilt the inclinometer away from the axis the numbers go up.
I’ll try to get the other info you requested ASAP, but most likely tomorrow as I have another busy evening in store.
Thanks again.

John

 

[JFOK]

Brian,

I took the 2 pictures you requested and when I get a chance later this evening, I’ll post them.
Thanks for your assistance.

John

 

[a33]

A33,

When I tilt the inclinometer away from the axis the numbers go up.

OK.
That would mean that you use the inclinometer in a way that you don't measure the elevation angle of 47.35 ; but the (90 - elevation angle) of 47.35.

In that case the axis should be raised even more towards the sky (more horizontally), to (90 - 47.35) = 42.65 degrees on your inclinometer.
That would give the needed axis elevation of 47.35.


Sorry, all these numbers are confusing maybe.
That is why I myself always use the elevation angles to set a motor setup; otherwise I become confused myself.


I don't know if you want to change the angle already (and post a photo again), or wait for the reactions to your coming photoos of the present situation?


After that, the next step will be setting the declination angle/total dish elevation angle.

greetz,
A33

 

[JFOK]

A33,

I can raise the angle before I head out this evening. So what should the axis be raised to from its current reading of 47.4 ?

John

 

[a33]

Raised (more horizontal) from 47.4 to 42.65 on your inclinometer.

A33

 

[JFOK]

A33,

If I’m raising from 47.4 wouldn’t the number be higher not lower ?
Sorry for the confusion.

John