Elevation and disappeared satellites

[mindas]

Hi,

Can anyone explain me a simple thing about elevation? dishpointer.com says that elevation for Astra for my area is 28.2E is 25.4° whereas the same metric for Sirius 4.8E is 30.9°. So if a dish is moved (using a motor) from one satellite to another, how does it manage to get a good reception as the angle difference is over 5°? Also, does it matter if the dish is mounted higher or lower on the motor pipe (see the second image)?

The reason I'm asking is because of my pain of getting the dish to work. When installing, I've first set its elevation accordingly to my latitude (~51° - see first image) as was shown on the dish. By doing this, I've managed to get channels from Astra 28.2E without much trouble. However my main goal was to get a particular channel from Sirius 4.8E working and I had to do lots of voodoo while I've got it (I think I had to change elevation slightly). So I tightened the bolts and even managed to get reception from some other satellites, including 13E Hotbird and 19.2E Astra by moving the dish more east.

The most interesting thing is that I could not get reception from 28.2E any more then! Same happened for 1W Thor. I've tried walking the small steps (using tuner's fine tuning) from successfully working 4.8E Sirius by going westbound (I think I stepped for about 10 degrees) without any luck. And yes - I've tried different transponders. Same for 28.2E - stepped forwards and backwards, haven't seen anything! Any ideas what can be wrong (apart from the dumb installer)?

The dish width is 80cm and the tuner is TM5400. There are no obstacles, etc. The first picture shows the installation view from the east and the second from the west.

Thanks in advance for your help.

[Robbo]

Hi,

I don't think you have it set up quite right judging by your explaination.

Simply put, when the motor is at 0 the dish is at the top of its arc, i.e it will be looking up the highest there. As the motor moves either east or west the dish starts to point down more, until at the extremes it is pointing at the ground.

The way to get the motor set up correctly is to get it so that it follows the satellite arc correctly.

This is achieved by

1. Making sure the pole is 100% vertical
2. Set the motor elevation/latitude, which you appear to have done in your picture.

3. Send the dish to Thor, then adjust the dish elevation (declination) and swivel the whole lot round the pole for max quality signal on eg 11325H.

You should then be following the arc.

For futher details, have a read of the stickies in the FAQs section, there are three motorised setup guides to choose from, try satellitemans one, if you want a real quickie.


Just to re-iterate. MAKE SURE that the pole is VERTICAL. The mount you have used is difficult to get right, and not the best way to install a motorised dish.

Also, it does not matter where the dish goes on the motor pipe, less stress on the motor I think, the higher it is, but you have to make sure there is enough space for the nuts and studs.

PS, How do you type the degree symbol????


Robbo

[bigtee]

In a motorised set up, 'elevation' primarily refers to the setting on the motor (let's call it "motor elevation"; once ascertained, this should be set once and for all and not tampered with. Easiest way to get motor elevation right is to use your location's latitude when the motor has a latitude scale --- and it seems you have done this correctly.

Then the dish vertical positioning; in a motorised setting, this is called 'declination' but we can call it for now "dish elevation"; with this you have to be careful that the 'elevation' figure that you get from a place like dishpointer is the one for a motorised set up. It is very easy to pick the dish elevation settiig for a fixed set up from dishpointer and assume that it also applies to a motorised set up. (in fact I believe that dishpointer actually has a separate elevation figure for a motorised set up).

A good place to start with declination ("dish elevation") in a motorised setting is the motor manual which will have a recommended figure; alternatively, in the UK one can start by setting the dish more or less vertical and adjust to the position that gives best signal on the reference set up satellite which is Thor 1w for a lot of the UK.

[mrfixer]

hi mate i was having same trouble following the arc im using the same motor lol think i got my latitude and elevation wrong was having trouble getting alot of the west satellites and 4.8e will put meter on it in morning and go by your advice thanks for help and hope poster got it soughted

[RayB]

Originally Posted by Robbo

PS, How do you type the degree symbol????


Robbo

Hold the ALT key down on your keyboard and using the number pad, key 0176 and release the ALT key

If using windows, have a look at character map.