The satellite finder that I had goes inline between the dish and receiver cable. AS you point the dish closer to the correct position, the signal becomes stronger, and the needle move indicating the correct position is 'near'.
You do not need power to the device, but the receiver has to be on.
I also noticed that the 'noon shadow' is almost always the same with my dish. So If I was to park in a location where trees cast a shadow on my RV, even my automatic dish will not get a signal, because the tree will block it. One out of the way desert location, I was having difficulty finding the dish, until noon the next day, when I pointed it south. As soon as the dish arm cast a shadow on the dish, I was able to get a signal.
So if you look at a 'connected' dish, then see what the shadow looks like at 11 am, noon, and 1 pm, you will get a idea of what it 'should' look like for your part of the country. It will change as you move east and west of Texas (where the satellite is located).
Another way I would aim my satellite when in a campground (before getting my automatic dish) was to look at the neighbor's dish. If it was pointed this way or that, I would start out at that direction, then go from there. This lead to the upgrade by buying a $40 'marriage saver' aiming device, then the $1,000 automatic dish.
Good luck,
Fred.
