am on the arc?

Bogger77

Hi guys,
Setup a motorised dish last weekend, I'm having trouble locking onto any sat's west of 5W, I can track the following sat's without any issues.
5W, 1W, hotbird, Astra1, Astra 2 as well as some others between 13E and 28E, but I can't manage to pick up hispasat on 30W.
I'm using a 1M dish on technomate h - h motor, with a TM 1600 reciever. Uals didn't find any sat's so I'm using diseqc to store sat positions.
There's no obivous obstructions, as dish is at same level as the roof on the closest building, and gorbtrack says its not blocking.

Any ideas?
Thanks
B

fat-tony

I would think from what you say that your dish is not mounted exactly in line with the centre of the motor arm (the bit that turns). You are obviously tracking part of the arc because you are getting 5W to 28E, which are all East of the highest point of the arc in Ireland. If you started with the dish pointing slightly East of the centre line of the motor arm, then the error will rapidly increase as you turn West.

A 1M dish is big and awkward to manhandle when you're up a ladder (I know, because I've been that soldier:)), but you must ensure that the dish lines up with the centre of the motor arm. There is usually a line on the arm and you need to make sure the mounting bracket of the dish is spot on centre of this. Once the dish is central lock it down and don't move it subsequently. Make sure the elevation on the motor scale is set appropriately - usually 53 degrees or 90 minus 53 degrees (depends on motor model) and then leave that setting alone. Then you drive the motor to its zero position. Then you rotate the whole motor and dish assembly together on the mounting pole which is attached to the wall and point it due South as accurately as you can. The mounting pole needs to be absolutely vertical , otherwise the dish won't track accurately.
When you have the dish assembly pointing South, and you have your coordinates in the receiver, you can use USALS to drive the motor to 5W (if you are in the East of the country - or whatever sat is highest at your longitude). You won't get anything - unless you've been stunningly accurate in pointing the thing South to begin with. Now you move the whole motor assembly and dish by hand on the mounting pole until you get reception. Tweak the dish declination (elevation) up and down to peak the signal and rotate the LNB in the holder to optimise quality. Tighten up the bolts and try East and West for other sats using USALS.

If you use Diseq 1.2 to find satellites, you may find that the numbers in the receiver don't match those default settings in the motor. What usually works, though is position 1 - which is Hotbird. If you set up the dish as I suggested - zero position, pointing South, then when you select Hotbird on the receiver, the dish should move South East and stop. You then turn the whole assembly by hand to tweak the reception etc... and off you go.

I find the Diseq 1.2 system to be the handiest for me because, when we get a storm, the dish will move (believe me a 1M dish will move on its mounts unless it's top notch). You can then tweak the reception using the remote control on the receiver and store the new position. You can continue this after every storm until the dish moves in elevation, when you get back on the ladder and start the whole process again. Now why doesn't someone design a motor which moves in elevation via remote control I never had this problem when I had an 80cm dish, but no ... I had to go to the limits of my Moteck.... it's all good fun really:D

Bogger77

Thanks Tony
I'll give this a try in 2 weekends. The pole was positioned by a Steeplejack / SteelErector using laser level, and is true in vertical on left to right, and front to back axis, so that's not likely to be problem. It might be just the position on the motor arm. I'll get that looked at, if the dish is too heavey we can use guy ropes to take the weight ;-)

Thanks C