Hi all, I came up with a simple way to brace the BUD so I can safely remove the bolt from the actuator and then move the dish as far to the east as it will go. What a difference! I can easily reach the feedhorn now and service/check things.
Now that I can reach the feedhorn I started checking things. First was the feedhorn centering. It was more involved because of the octagonal shape of the dish. The hub had a small hole at the center so I used it to measure out the same distance at three points then found the radius of 1/3 of the dish. From these three points I checked the distance to the center of the feedhorn and found it was out a little (two of the points are the same but the third was 1/2 inch off) so it is off center a bit. Anybody have a tolerance for a 10 foot dish?
Next I used the same hole in the center of the hub to check the feedhorn alignment. Came up with the idea of using a simple speed square and a string tied to a nail and pushed into the center hole to check the alignment. (I'm too cheap to buy a laser level and the string worked quite well).
Found the feedhorn was off quit a lot and adjusted it closer. Still need to work on it some more but I picked up a few points on the SQ so I must be improving things.
Next I ran two strings across the face of the dish and found 1/2 inch between the strings. What would be a good tolerance on the string test? I plan to do it again when the weather is better and I can spend more time on it.
Something else I want to do is check the FD. Need to read up on how it is calculated.
Sure have learned a lot putting up the BUD and it has been a lot of fun too.
Got to run, DC
Now that I can reach the feedhorn I started checking things. First was the feedhorn centering. It was more involved because of the octagonal shape of the dish. The hub had a small hole at the center so I used it to measure out the same distance at three points then found the radius of 1/3 of the dish. From these three points I checked the distance to the center of the feedhorn and found it was out a little (two of the points are the same but the third was 1/2 inch off) so it is off center a bit. Anybody have a tolerance for a 10 foot dish?
Next I used the same hole in the center of the hub to check the feedhorn alignment. Came up with the idea of using a simple speed square and a string tied to a nail and pushed into the center hole to check the alignment. (I'm too cheap to buy a laser level and the string worked quite well).
Found the feedhorn was off quit a lot and adjusted it closer. Still need to work on it some more but I picked up a few points on the SQ so I must be improving things.
Next I ran two strings across the face of the dish and found 1/2 inch between the strings. What would be a good tolerance on the string test? I plan to do it again when the weather is better and I can spend more time on it.
Something else I want to do is check the FD. Need to read up on how it is calculated.
Sure have learned a lot putting up the BUD and it has been a lot of fun too.
Got to run, DC
