Dish heading
- Thread starter owlbox
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Once the dish is installed, if you look where it's pointed does that magnetic bearing on a compass agree with the number from the program. There is a good 15 degree difference between where the compass needle points and what the true heading is.
All you really need to know for a GENERAL-BASIC rule, is the 61.5 satellites are approx. 23,300 miles above the equator and the VOOM dish will need to point in the GENERAL direction of Flordia, infact a little east of Flordia out over the Atlantic.
On the east coast the dish elevation of the line of site varies from 40-50 degrees.
On the West Coast, 9-15 degrees, so you west coasters may have more line-of-site issues than the east-coasters.
Also, the actual signal from "space" doesn't come straight into the dish surface, you will actually have approximatly an additional 20 degrees to have for the signal to "make-it" over any obsticals.
Hope that makes it easy to BASICALLY know what direction your VOOM installer needs to point the dish.
On the east coast the dish elevation of the line of site varies from 40-50 degrees.
On the West Coast, 9-15 degrees, so you west coasters may have more line-of-site issues than the east-coasters.
Also, the actual signal from "space" doesn't come straight into the dish surface, you will actually have approximatly an additional 20 degrees to have for the signal to "make-it" over any obsticals.
Hope that makes it easy to BASICALLY know what direction your VOOM installer needs to point the dish.
rtfm 
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I finally read what it says on the screen for the az/el calculator program. It says the s/w compensates for the declination, i.e. the angles calculated and displayed are true not magnetic headings. For me in MA it indicates 181 deg at an elevation of 40 deg. The only reason I'm concerned is I have a lot of trees on the property but there are some large gaps in certain directions. I think I have one that lines up with where Voom is parked. The 40 deg is a big help.
)I finally read what it says on the screen for the az/el calculator program. It says the s/w compensates for the declination, i.e. the angles calculated and displayed are true not magnetic headings. For me in MA it indicates 181 deg at an elevation of 40 deg. The only reason I'm concerned is I have a lot of trees on the property but there are some large gaps in certain directions. I think I have one that lines up with where Voom is parked. The 40 deg is a big help.
What in the world are you talking about?! I've heard some really strange ways of defining look angles, but this one tops them all. The general direction of Florida?! Is that how you read a map and calculate direction? The signal from space doesn't come straight into the dish surface? Where did you get THAT from? OF COURSE the signal from the satellite goes straight to the satellite dish. It doesn't travel AROUND obstacles, that's the most ridiculous thing I have every heard. You need to read up a bit on basic satellite communications before giving out advice. Sorry to be harsh, but that's the type advice that just makes things worse.sat4me said:
orienteering basics 101
In my area, eastern MA, we have a 16 deg. W declination. If you look at where your compass needle finds magnetic north, you have to go 16 deg west to find true north. The program that Sean provided a link to, says the headings it gives are compensated for the declination in the area based on the zip code you furnish. So I take that to mean the headings are true. In my case it says 181 deg at 40 deg elev. So I'd expect to find the bird at 165 deg and 40 deg elev. Clear as mud??
In my area, eastern MA, we have a 16 deg. W declination. If you look at where your compass needle finds magnetic north, you have to go 16 deg west to find true north. The program that Sean provided a link to, says the headings it gives are compensated for the declination in the area based on the zip code you furnish. So I take that to mean the headings are true. In my case it says 181 deg at 40 deg elev. So I'd expect to find the bird at 165 deg and 40 deg elev. Clear as mud??
Never used the Dish az/el calculator myself, but if the program tells you that it has taken mag dec into account, then I would not think you would subtract/add the figure. Taking mag dec into account would mean that it has already done the calculation for you. With that in mind, you would then point your compass at the number the program provides. If it did not take it into account, THEN you would subtract/add the mag dec.
A little clarification!!!......as to the signal not going "straight" into the dish. I am pretty sure what he meant is that the dish does not point exactly to the satellite. On a Cband dish which is round and the feedhorn is exactly in the center, you need to point directly at the satellite. HOWEVER..on Voom and just about every other DBS service they use an offset feedhorn which lowers the look angle. For example here on the west coast, if you look at the face of my dish, it appears to be pointing towards the ground. The signal hits the top portion of the dish and then bounces towards the feedhorn at the bottomM Law said:
