Usals problem & alignment

[jeallen01]

It shows the approximate bolt configuration and approximate angle of dangle.

OK, I get it!- hope RedAlert also does

 

[Red alert]

THere's no way the latitude you've set on your motor is correct, it should be further up the scale. When you set it, check you are using the latitude scale. It looks like the dish elevation is set too low as well. The bamboo fence shouldn't have any effect.

Thanks for comments all. That is exactly what happened. I made a silly mistake and I must have not tightened the motor on the sides when i set the latitude, so it slipped down. . So thanks all for noticing. I managed to get signal on thor but its only 40%, and getting only sats in the centre of the arc nothing east or west, so more tweaking required. Is there a detailed guide on tweaking? I look at the arc drawings and try to compare the problem I have but gets confusing which one is the exact problem.
I only had an hour on the dish then it started raining , so hopefully can do some more tweaks tomorrow if the weather improves a bit. I must say the brackets on the Technomate are much easier to tighten than the Stab and they square up very nice once, much easier to level. The latitude is just over 53 and the dish elevation is set at 24.

 

[jeallen01]

One thing escapes me - I think I have checked the whole thread, but I can't seem to find out exactly which dish (brand, type) you are using, and thus please confirm?

Why do I ask that? Because the specified declination angle varies from brand to brand and then sometimes from model number to model number!

Thus, if you aren't starting with with the correct declination angle, then you have the wrong "starting point"!

 

[Channel Hopper]

One thing escapes me - I think I have checked the whole thread, but I can't find out exactly which dish (brand, type) you are using, and thus please confirm?

Why do I ask that? Because the specified declination angle varies from brand to brand and then sometimes from model number to model number!

Eh?

If the post is dead vertical, then the alignment is based on the locking of longitude and latitude of the gearbox alone. The declination angle (elevation adjust of the fixed dish) brings the focal point into alignment with the equatorial line at which the geostationary satellites rest. The latter does not need to be known if the DiSEqC function is working and one satellite on the arc is peaked, though the tolerance of the gears, distortion of the dish and boom arm, plus the cheese that some posts and clamps are made of will impact on the final fettling.

 

[Red alert]

One thing escapes me - I think I have checked the whole thread, but I can't seem to find out exactly which dish (brand, type) you are using, and thus please confirm?

Why do I ask that? Because the specified declination angle varies from brand to brand and then sometimes from model number to model number!

Thus, if you aren't starting with with the correct declination angle, then you have the wrong "starting point"!

I have Gibertini 100 XP. I probably still need to tweak things more

 

[jeallen01]

The Gibertini website gives these specs for the XP series.

"Declination angle" is not stated but I'm guessing that "offset pointing angle" means the same, and thus around 21 degrees for most of them including the XP100.

 

[Red alert]

The Gibertini website gives these specs for the XP series.

"Declination angle" is not stated but I'm guessing that "offset pointing angle" means the same, and thus around 21 degrees for most of them including the XP100.

Does this affect the motor setup or declination angle I need to set the dish at?

 

[jeallen01]

Does this affect the motor setup or declination angle I need to set the dish at?

I would suggest that you start by setting the declination to around 21 degs, and then "tune up" the dish longitude setting - other opinions may differ!
OTOH, @Channel Hopper's comment about the "cheese factor" in some motor mounting clamps could be relevant - but that "takes time" in my (limited!) experience to manifest itself (some months ago I posted what I had to do to the clamps on my, much heavier - weighs 2x as much -, Gibby 125 to limit the possibility of that).

 

[a33]

Does this affect the motor setup or declination angle I need to set the dish at?

No, not at all! (As CH also wrote.)
Use the dish elevation scale value you found in the manual ~ though it probably is not using the (better) modified motor angles, as referred to in post #8 here.

Best tweaking is done, by setting the calculated (modified) angles as precisely as you can, right from the start. That saves a great deal of time, of actual tweaking.

Jeallen01 is confused by offset angle of the dish. As also happened in this thread, post #3 : Dish angle - SatsUK
My attempt to explain the setting of the declination angle, in post #4 of that thread, was not quite successful it seems. :-(

greetz,
A33

 

[Red alert]

No, not at all! (As CH also wrote.)
Use the dish elevation scale value you found in the manual ~ though it probably is not using the (better) modified motor angles, as referred to in post #8 here.

Best tweaking is done, by setting the calculated (modified) angles as precisely as you can, right from the start. That saves a great deal of time, of actual tweaking.

Jeallen01 is confused by offset angle of the dish. As also happened in this thread, post #3 : Dish angle - SatsUK
My attempt to explain the setting of the declination angle, in post #4 of that thread, was not quite successful it seems. :-(

greetz,
A33

Thanks for that, will try to set up using modified angles, weather permitting. So looking at the modified motor angles as my latitude is 53.456 then modified latitude is 53.65 but probably best to set at 54 since my latitude isnt 53 exactly? Then a declination angle of 6.88. How does that translate to dish elevation scale on Gibertini xp 100?

 

[Red alert]

Thanks for that, will try to set up using modified angles, weather permitting. So looking at the modified motor angles as my latitude is 53.456 then modified latitude is 53.65 but probably best to set at 54 since my latitude isnt 53 exactly? Then a declination angle of 6.88. How does that translate to dish elevation scale on Gibertini xp 100?

Forgot to mention I got the above values from here

Modified angles

Does that table apply to offset dishes or just prime focus?

 

[Channel Hopper]

Close enough, though the declination angle will be the two numbers combined (or subtracted, depending on whether the Gibertini is inverted or not)

 

[Red alert]

Close enough, though the declination angle will be the two numbers combined (or subtracted, depending on whether the Gibertini is inverted or not)

At the moment its set up normally, will consider inverted in future. Booklet says my dish elevation should be 22.4, so using modified angles would that mean i need to set dish at 23.12 and motor at 54?

 

[a33]

Forgot to mention I got the above values from here
Modified angles
Does that table apply to offset dishes or just prime focus?

Applies to motorized setups; all kinds of dishes.

For modified motor latitude: add .65 to 53.456 and you get 54.106 degrees.
For modified dish declination: Go somewhere inbetween table values for lat 53 and 54, and get 6.92 degrees.

If booklet says 22.4, shaft bend of the motor is likely 30 degrees.
New dish elevation scale value therefore is 30 - 6.92 = 23.1 degrees.
(All values for regular, non-inverted setup.)

Setting motor elevation angle (modified latitude) correctly is the most important thing, e.g. at the motor house/base of the shaft (perpendicular to axis angle).

Greetz,
A33

 

[Red alert]

Applies to motorized setups; all kinds of dishes.

For modified motor latitude: add .65 to 53.456 and you get 54.106 degrees.
For modified dish declination: Go somewhere inbetween table values for lat 53 and 54, and get 6.92 degrees.

If booklet says 22.4, shaft bend of the motor is likely 30 degrees.
New dish elevation scale value therefore is 30 - 6.92 = 23.1 degrees.
(All values for regular, non-inverted setup.)

Setting motor elevation angle (modified latitude) correctly is the most important thing, e.g. at the motor house/base of the shaft (perpendicular to axis angle).

Greetz,
A33

Thanks for the explanation. Would I also have to enter 54.106 in the tuner setup on receiver for latitude?

 

[a33]

Thanks for the explanation. Would I also have to enter 54.106 in the tuner setup on receiver for latitude?

Good question, and I think the answer is indeed: YES.
See this post: USALS Notebook

However, the difference in USALS-outcome is very very small, as I concluded:
¨I compared the values of the normal hour angle and the adjusted hour angle for some earth coordinates and a range of satellites, and the difference between them was never more than 0.07 degrees, I'm afraid."
So I think you will hardly notice any difference, in praxis, with a small dish. I would recommend it for dishes > 200cm, but I don't think there are USALS-devices available for dishes that size...

Greetz,
A33

 

[Red alert]

Good question, and I think the answer is indeed: YES.
See this post: USALS Notebook

However, the difference in USALS-outcome is very very small, as I concluded:
¨I compared the values of the normal hour angle and the adjusted hour angle for some earth coordinates and a range of satellites, and the difference between them was never more than 0.07 degrees, I'm afraid."
So I think you will hardly notice any difference, in praxis, with a small dish. I would recommend it for dishes > 200cm, but I don't think there are USALS-devices available for dishes that size...

Greetz,
A33

Thanks for the help, it seems with this motor I have lost partial line of sight to 1 west and any sats beyond 1 west, because the dish is lower on the pole. I can peak 1 west to 54 %, which is fine as long as I can pick up the eastern sats, which I do but not peaked signal. All the eastern sats have clear line of sight. Seems I have problem when I tighten the motor brackets they go out of level slightly on the left, is there a guide to properly tightening bolts on motor so you dont lose the arc?

If the dish was on a wall it would have less problems, but I unfortunately cannot put it as front of house is south facing rather than the garden. long story. I suppose I can try inverting the dish but dont know how much effort and time is required, I wouldnt know where to begin.

 

[Channel Hopper]

Good question, and I think the answer is indeed: YES.
See this post: USALS Notebook

However, the difference in USALS-outcome is very very small, as I concluded:
¨I compared the values of the normal hour angle and the adjusted hour angle for some earth coordinates and a range of satellites, and the difference between them was never more than 0.07 degrees, I'm afraid."
So I think you will hardly notice any difference, in praxis, with a small dish. I would recommend it for dishes > 200cm, but I don't think there are USALS-devices available for dishes that size...

Greetz,
A33

Thanks for the help, it seems with this motor I have lost partial line of sight to 1 west and any sats beyond 1 west, because the dish is lower on the pole. I can peak 1 west to 54 %, which is fine as long as I can pick up the eastern sats, which I do but not peaked signal. All the eastern sats have clear line of sight. Seems I have problem when I tighten the motor brackets they go out of level slightly on the left, is there a guide to properly tightening bolts on motor so you dont lose the arc?

If the dish was on a wall it would have less problems, but I unfortunately cannot put it as front of house is south facing rather than the garden. long story. I suppose I can try inverting the dish but dont know how much effort and time is required, I wouldnt know where to begin.

Last post on this thread

Televes or fracarro?

So you want to receive 30 West as your most westerly satellite now, and not 7 West, as stated in your opening post? Maybe you could also setup motorized til 7W, and add a separate dish for 30W at a suitable location? What part of the house and the (garden) ground in the picture are actually...

satellites.co.uk

 

[Channel Hopper]

Or this

Just Sharing This - Spotted last week.

Sat on the train last Friday heading through south London into St Pancreas and spotted a large, inverted offset on a rooftop somewhere near South Croydon and Purley. We were going too fast to get a photo of it but I've been looking at Google maps and have possibly found it. I say possibly...

satellites.co.uk

 

[Red alert]

Interesting. This is something I want to try have a go at. Is there some calculation I have to do for latitude and Dish Elevation? All the values inverted?