I got Lucky!!!
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A lot of people think that where the LNB is pointing is where the signal comes in from. Gerry is right on the money with his picture and explanation. Also those trees don't look that close to even have to worry about anyway.
after looking at the pic... it's likely i STILL got lucky... but the signal is comeing from high up. i must just be missing the tree to the left there... and NOT pulling the signal through that shole in the branches.
the tree is close though. it's about 30 yards from the dish.
the tree is close though. it's about 30 yards from the dish.
e0rbay said:
HI eOrbay, I had a problem with an install a while back. It was a lot like your situation the signal just had room to make it thru the trees and he didn't tell me about it. Then a 2nd installer had to come back for an unrelated problem. He seen where the dish was placed and asked if I put the dish up or if an installer did it. So when I told him that the installer did it he called his dispatch/office and said that he would be here longer than expected. He actually went and moved my dish so that I wouldn't have the same problem that everyone is saying you are going to have.
Well any way don't let'em get to you and have fun here on the forums.
Bob
I have installed a few dishes where the signal woudl come in between two trees just barely and knew that there would be a problem in the future to where I would have to move it and sure enough I had to. The thing is I did not know how much more the trees would grow and knew it would be a close call so I knew I was better off waiting until the trees grew out more before moving the dish. It was not far from here and I do not encounter such a situation at most people's houses.
If a laser that was on the lnbf arm and pointed towards the trees then it would indicate the azimuth of the signal, as Foxbat indicated above. The signal would be coming from above that signal beam in a diagonal fashion, which means above and to the left of where that laser pointer is pointed at.
There is a certain type of mathematical calculation that tells you how many degrees above the actual elevation setting on the dish that the signal is coming from. Since there is also a skew on the dish and have two satellites coming in on that dish at different elevations then it would be different on each side of that lnbf arm. In the case of the skew being over 90 the 110 satellite is higher up in the sky than 119 is. Being at the dish looking towards the trees the 110 is on the left and 119 is on the right. 110 is easier to pick up as a result than 119 because of the higher elevation to get over the tree leaves.
If a laser that was on the lnbf arm and pointed towards the trees then it would indicate the azimuth of the signal, as Foxbat indicated above. The signal would be coming from above that signal beam in a diagonal fashion, which means above and to the left of where that laser pointer is pointed at.
There is a certain type of mathematical calculation that tells you how many degrees above the actual elevation setting on the dish that the signal is coming from. Since there is also a skew on the dish and have two satellites coming in on that dish at different elevations then it would be different on each side of that lnbf arm. In the case of the skew being over 90 the 110 satellite is higher up in the sky than 119 is. Being at the dish looking towards the trees the 110 is on the left and 119 is on the right. 110 is easier to pick up as a result than 119 because of the higher elevation to get over the tree leaves.
Stargazer said:
kewl info. thanks.
the dish pointing to the 110 and 119 is actually A-OKAY. i have completely open sky on that one. the pic i attached is of my second dish that i'm using for the 148 for my locals. not sure what that means in terms of the actual location where the signal is coming... but since to the right is nothing but tree (lol) i'm guessing it's from above and slightly left.
maybe if i ever have a dish guy come out again... i'll see if he has one of those gizmos someone mentioned that figures out the actual sat location.
We got so far down the post that I forgot that this was only for the 148 satellite. I imagine that a lot of installers do not have such a tool.
Chelsea, do you mean mean add 28 to the elevation number to get the true angle that the satellite signal is coming from?
No. Let's not make it this more complicated than it needs to be.Stargazer said:
Forget about the dish itself. Period. Let it be.
The elevation scale on the dish mount is calibrated to include whatever the bounce angle of the reflector might be - 28 seems to be a likely number, but it simply doesn't matter.
The elevation number from the Point Dish screen is the TRUE elevation. Use a protractor or sight angle gauge device thingie. It ain't rocket science.
If you're actually so close to a suspected obstruction, just put your eyeballs down around the midpoint of the dish and sight the angle. If you really want, do it from both sides.
If it's so close that you are worried about being exactly parallel to the dish's azimuth, use a yardstick held parallel to the LNB arm.
However, if all this is really all that tight, you gotta be thinking about doing something else because you're just asking for trouble anyway.
Cascade said:
While searching for a suitable spot to pole-mount a dish (I have a tripod onto which I mounted the dish and moved it around to various places in the yard), I tried one spot that I felt certain would be completely blocked by my trees. To my utter amazement, I got a usable signal through the branches and leaves! It was borderline, and the picture would pixellate when the wind blew, but it worked!
It's amazing how robust satellite technology is...
Thats what I was trying to figure out, if the signal was actually shooting the dish at a 28 degree angle above what it indicates on the elevation. If someone was to use a laser pointer and wanted to have some kind of idea of where the signal was coming from, then you would have to raise the elevation (perhaps by 28 degrees) over what the elevation calls for (or where you are currently receiving a signal). The mast would have to be level in order for the elevation number that the manual (or signal strength screen) calls for.
As I've said before, the Point Dish elevation IS the angle of the satellite above the horizon. Period. No adjustments. Nothing. Every installer knows this.
But just to prove it, I just went out and measured it all.
My Elevation = 43 (110=44, 119=42), both on Point Dish and as set on the mounting scale.
Dish face = 67, so IT'S 'elevation' is 23. That is, a line perpendicular to the face is looking 23 degrees above the horizon.
LNB arm = 29, which is pretty meaningless really, except it can be used to derive the other numbers if the arm is all you can measure.
LNB 'look angle' is close to 0 (level) - can't measure it due to rounded housing.
So, within margin of measurement and eyeball error, the bounce angle is 23, doubled it becomes 46 - magically close to the Elevation - and remember, my 'look angle' of 0 could be off a bit - it was by eyeball.
My other dish (out of reach of my stepladder) has Elevation 26 and it's dish face is almost vertical - which matches up with the bounce angle again.
It can be hard to visualize, but I really don't want to have to draw it.
But just to prove it, I just went out and measured it all.
My Elevation = 43 (110=44, 119=42), both on Point Dish and as set on the mounting scale.
Dish face = 67, so IT'S 'elevation' is 23. That is, a line perpendicular to the face is looking 23 degrees above the horizon.
LNB arm = 29, which is pretty meaningless really, except it can be used to derive the other numbers if the arm is all you can measure.
LNB 'look angle' is close to 0 (level) - can't measure it due to rounded housing.
So, within margin of measurement and eyeball error, the bounce angle is 23, doubled it becomes 46 - magically close to the Elevation - and remember, my 'look angle' of 0 could be off a bit - it was by eyeball.
My other dish (out of reach of my stepladder) has Elevation 26 and it's dish face is almost vertical - which matches up with the bounce angle again.
It can be hard to visualize, but I really don't want to have to draw it.
Sounds 'bout right to me. Except where'd the "50" come from - just averaging my shot @ 46 and the other guys 28*2=56?
SimpleSimon said:
Pretty much, I don't care to go out and measure mine.
You can think of the geometry for the small DBS dish as just a section of a large BUD. Cut a circle about 20" in diameter from somewhere off the large reflector and throw the rest away. Keep the lnb and reflector is the same position and you can visualize what the small dish is really doing. It you took the small DBS dish and extended the reflector to finish its curved surface you'd find the LNB to be at the center of a parobolic reflector.
This image is of a 90 degree reflector.
gp: Your concept is spot on, but it should be noted that the curvature is different between a little dish and a BUD. Little dishes have a deeper curve, as shown by the focus point being closer to the dish face. There's a limit to how far the signal from the dish edge can be 'turned' by the LNBFs feedhorn. Let's say it's 45 degrees (I have no idea of the real number, but it doesn't matter). The intersection of 45 degree lines from the edge of a large dish are farther away from the face plane than the same on a smaller dish.
well... i took what chelsa said... and what simon said... and then kinda combined the two... seemed to be about the same.
if you look from one side of the dish (in the middle) it looks like it's about the same spot in the sky as if you take a protractor (in my case a whiped up a little something using a carpenters square and a stick... LOL) and set it to 28 degrees off of the LNB arm.
both seem to point in about exactly the same spot... which appears to be just above where my pic cuts off...
which is a lot better for me anyway... since the tree is going to take a heck of a lot longer to grow taller than it would to grow outward...
anyway... it was fund to figure out. thanks for all the info.
if you look from one side of the dish (in the middle) it looks like it's about the same spot in the sky as if you take a protractor (in my case a whiped up a little something using a carpenters square and a stick... LOL) and set it to 28 degrees off of the LNB arm.
both seem to point in about exactly the same spot... which appears to be just above where my pic cuts off...
which is a lot better for me anyway... since the tree is going to take a heck of a lot longer to grow taller than it would to grow outward...
anyway... it was fund to figure out. thanks for all the info.
Looks like if the dish was put just to the left of where it is at now then it would have a good clear line of site if the signal is coming in where the red circle is as you indicated.
