thanks to tech

[TuxCoder]

Finally I have decent reception of locals! After the initial install about 2 months ago my signal strengths had always been around:

110tp11&12: 101
119tp11&12: 89
105tp15 (my locals): 43

Now after sunday's visit following extremely unstable signals, I have:

110tp11&12: 101
119tp11&12: 101
105tp15: 61

But this was after he was here 2.5 hours, eventually he ended up relocating the pole slightly (and using a new one of course) to make sure it cleared my wooden deck fence. And he completely swapped out the SuperDish & LNBs.

But a simple question: exactly where is the dish pointing in the Clarke belt, since it's looking at 3 slots? My 522 says use azimuth 215 for my location, but when measured with a compass the dish seems pointing quite a bit east of there. I asked the tech sunday and he says it needs to be pointed slightly east of 105????? I know the dish is pointing where it needs to be, but I just would like to clarify where that is so I know I'm reading the compass correctly (so I can install my new FTA dish when it arrives ).

 

[PSB]

The Tech. means its orbital position/slot of 105w (in the sky), you are getting mixed up between that and the azimuth.(compass)

The azimuth for 105w in your area is around 212 deg.

Some of the Superdish signals bounce in off the sides of the dish so the dish appears to be pointing in another direction.

 

[SimpleSimon]

Also, you have to consider magnetic deviation.

Your compass does NOT necessarily point to true north, but the azimuth numbers on the Point Dish screen are always "true".

 

[TuxCoder]

Thanks for the pointers guys but I am already taking into account those concepts (see this post).

I moved away from the dish and verified no magnetic/metallic interference, but it just looks like it's pointing at ~203 compass-wise, meaning with my magnetic deviation (which by now is around 5 degrees east declination) it's about 198 degrees. Unless I'm doing the math in the wrong direction, since I keep bouncing between thinking I understand it and being utterly confused.

 

[Grandude]

Also, you have to consider magnetic deviation.

Your compass does NOT necessarily point to true north, but the azimuth numbers on the Point Dish screen are always "true".

Simon,
I was always under the impression that the azimuth given on the point dish screen was magnetic north. That is what I have always used and it always worked for me.
(I'm willing to be corrected and chastised if wrong)

 

[SimpleSimon]

Grandude: You're wrong, but no chastisment needed. You might be in a part of the country (a lot of it) where the deviation is small. Anything less than 5 degrees won't even be noticed when aiming the dish - after all the azimuth is just the starting point. Check out the map here: http://www.csgnetwork.com/antennasatelazposcalc.html and let us know.

 

[Grandude]

Simon,
I have two Dish 500 installation manuals with Angle tables and, as I thought, the instructions in the books say that the azimuth for the zip codes listed is "already adjusted for magnetic deviation so you can use the reading on a compass". I am now looking at the Peak angles setup screen on my 811 and although it doesn't say the same thing, the numbers are the same as in the book so my understanding is that no correction for magnetic deviation is needed if using the Dish setup screen or manuals.
The site you reference above gives true north and deviation numbers which added/subtracted from the satellite and location reference end up with approximately the same numbers as the numbers given by the Dish charts or Peak Angle screen.
Note: You are correct when using the above referenced site and I, it would appear, am right when using the numbers provided by Dish. Guess it is a standoff.

It has been some time, about five years since I've installed a dish so had to check my presumed facts.

 

[SimpleSimon]

Well, I'll be gol-danged. Seems like you're right - at least for running the test for my location. The mag dev seems a bit off, but it's closer than without it. And you win both sides - because I've been telling folks that Point Dish is absolute and I was wrong. :shocked:

Well, I guess aiming these things is easier than even I thought. I always started a knudge over from the azimuth number and could always get signal to start with, but I never thought about which way I was twisting it to lock in the birds - it was always by tone.

Sure glad I'm not out on one of the coasts - I would've been killing myself - or actually, I would've learned about this long ago.

 

[Rich McGirr]

Speaking of if I'm in CT do I add or subtract 15 from my compass reading?

 

[SimpleSimon]

Per http://www.sadoun.com/Sat/Installation/Satellite-Heading-Calculator.htm
you would add the 15 - but as Grandude says, Point Dish seems to already have it factored in.

Do me a favor if you can - compare your Point Dish numbers to the ones from the site above and let us know the results.

 

[TuxCoder]

Ah, I can feel it, we're nearing the kind of explanation I was looking for to begin with. Not that the replies so far haven't been good and useful in clearing some other things up.

I realized a major mistake on my part yesterday when I revisited my new dish with my compass. In the past I was measuring where the LNB arm is pointing but after looking closer, it's actually pointed a bit east of where the dish is pointing. Then looking at the LNBs that makes sense considering the signal reflection of the dish.

So, measuring via the pole bracket on the back of the dish, it is in fact pointing spot-on 215 which is what my 522 tells me to point at (apparently already taking magnetic deviation into account). But while making the E* dish easier to install, it doesn't help me much when trying to figure out what the TRUE azimuth of the dish is, when I'm also trying to understand magnetic deviation.

Two simple questions to hopefully wrap this up for me, pick either one to answer and I should be set :
1) What specific orbital slot (not azimuth) is a SuperDish 105 (anyone's, not just mine) pointed at, to get the best signal on 105, 110, and 119? My guess would be it's pointing at 105 since it's the weakest satellite of the three, but I would like to hear the "undisputable" truth.

2) I'm in Ohio, and the heading of "something" as read from the compass (thus "magnetic" azimuth) shows 215. Therefore, is the TRUE azimuth of that something at 210, or is it at 220 (my dev. is around 5). Alternately, depending on which way you think, if I want to look at TRUE south, 180, should I be looking down my compass' 175 or 185 line?

If you read question 2 carefully, you'll see I get confused by statements as simple as "in your area add 5 to the compass reading" because that is still ambiguous. It all depends on (a) if you are reading a heading and want to know what it really is, or (b) if you know a heading you want but need to know where to read on the compass.

 

[SimpleSimon]

A1: I believe that the SD points to 105 - I just cross-checked it against 'conventional' aiming and also looked it up in the SD manual.

A2: I also get confused by which way the correction goes. Your compass needle points west of true. So, if you are facing magnetic north, you need to turn slightly clockwise to be facing true north. I set the bezel on my compass years ago so that when I line up the needle, the BASE points "true". In my case (I'm in the west), the bezel is rotated clockwise from 'centered'. You would be the opposite, so the 185 line on the bezel would be aligned with the base, and the base is now 'true'. Gosh I think that's right.

P.S. Thanks for confirming Grandude's observations for me.

 

[Grandude]

Just got back from a three day trip to Bend, OR to visit with my daughter and three of the grandchildren, they all from Helena, MT. To my surprise, Simon, you agree with me.
This situation came up on another forum, mutual funds to be exact, and a guy named Sailorjohn was having difficulty setting up his dish until he discovered that the numbers Dish was giving him were already corrected for magnetic deviation. He was, like you, too used to making the correction all the time, being a sailor. This was back when we first joined Dish very, very early in the game. I've been a E* customer ever since.
Cheers from the far left coast were magnetic deviation is near its max for continental US.
PS. Still using the cheap compass that came with the Dish installation kit. I keep telling myself I should get a real one.

 

[SimpleSimon]

Brian: I'm sorry you're surprised that I agree with the facts. I believe in facts, and have no problem at all admitting when I'm wrong. As per an earlier post of yours in this thread, it looks like you're the same.

Nowadays many people believe in what they THINK are facts, and that's a problem. Fortunately, geometry and physics don't pay any attention to opinion, and it's easy to prive (or disprove) a point. That's why I like them so much.

 

[Grandude]

Simon,
Sorry, it has nothing to do with you. I am a staunch conservative living with a liberal wife in liberal la la land and am always surprised when I make a point in fact and it is believed.

 

[SimpleSimon]

LOL - no forgiveness needed - you've got enough trouble on your own. I'll give ya any support I can.