Compass Problem SOLVED!

[Arabi]

When my dish was pointed at a satellite, the compass would be affected by the signal. From my location, my Azimuth was supposed to be 210 to hook IA-5. I am new to this part of the country, so my sense of direction is lacking. Every time I used the compass, I hooked satellites that were difficult to identify on lyngsat.com . It turns out they were all WAY East of my target. I got the sense that there was a problem when I realized that for one of these aims I was pointed at a tree top in my yard, for another I was pointed at a different tree in my neighbor's yard. IA-5 wound up being in line with the peak of my neighbor's roof, about 45 degrees away from my initial aim.

How my problem was solved:

I got out the site map of my house (from among my home purchase documents) which had a compass indicator for North. I lined up the line representing the South wall of my house in the drawing with the physical south wall of the house and checked the compass. Doing this inside my house, it seemed apparent that the compass was nearly correct with the drawing, but 210 was pointing somewhere along my neighbor's roofline. When I went to the roof, I discovered that the closer I got to the dish, the compass would turn counter clockwise. I held the compass up at my neck height and estimated where it pointed relative to my neighbor's roofline and aimed the dish. I then tilted it up and down until I got a signal. Satellite HOOKED! But, after doing the scan on the receiver, I found stations that are only on AMC 3 (14 degrees EAST of where IA-5 is supposed to be!) Up on the roof again, I held the compass at neck level, and added 14 degrees. Noticed that the peak of my neighbor's roof was almost exactly in line with this Azimuth. Lined up the dish, tilted it up and down to find the signal, fine tuned it with the SF-10, and FINALLY HOOKED IA-5! Did the scan, and found 118 stations - OVER 20 in ARABIC!

I should note that since writing this explanation, I found the Geospatial government link www.ngdc.noaa.gov/seg/geomag/jsp/Declination.jsp to learn that my True South is 11.1 degrees clockwise of what the compass should show. So at my neck height, there was little if any magnetic interference from the dish to distort my readings - I just didn't understand about magnetic deviation. This still doesn't explain the other 34 degrees that my compass was off when using it behind the dish. I assume this was caused by the signal from the satellite I was pointed at.

I hope this helps someone to save some time and frustration.

Arabi

• I am located in Pasadena Maryland 39.11 Lat, 76.55 Longitude
• Fortec Classic Lifetime Receiver (couldn't find a model number)
• 90cm Dish
• Universal (FSKU-V)
• Manual positioning, I only want to watch Arabic programing, so I believe IA-5 is best. (SF-10 Satellite Finder for manual positioning)
• I have new Phillips brand RG-6 with Quad Shield Coax cable (50 Foot length)
• When I hooked IA-5 I found 118 channels on 5 Dec 06 from my location in Pasadena, Maryland. (when I was frustrated I wondered if it was even possible to hook IA-5 from where I live)

[rainman]

it was more likely interference from your metal dish.glad to here you got it figured out.

[elgemcdlf]

Agree with Rainman. A compas is affected by anything metal since they are magnetic

[wejones]

Originally Posted by elgemcdlf

Agree with Rainman. A compas is affected by anything metal since they are magnetic

Well, most metal isn't magnetic, but in this case yes.

But even if there isn't any metal around, there are often local variations that can be significant. When we first bought our property here, I tried using a compass to find the line of sight to a distant mountain we wanted to see from the house, and even out in the middle of the woods, we were finding more than 5 degrees difference in heading by moving only about 5 feet along the trail. Wasn't anything metalic for a quarter mile.
I also have one of those compasses similar to what Sadoun sells, although I didn't buy it at Sadoun, ie one of those things with the circular disk floating on liquid. Those look like they'd be accurate, and they are nice, because you can sight through the lid that pops up. Well the compass I have is off by about 10 degrees on average, and if I just let it sit there, the darn thing will slowly swing around up to 20 degrees off it's average setting. Darn thing is totally worthless. The best compass I have is an old boy scout compass I bought over 50 years ago.
I don't trust compasses much anymore, except to get a rough idea of what direction I'm looking. When I want to find an accurate heading to a satellite, I use the sun.

[bobkat]

Originally Posted by wejones

The best compass I have is an old boy scout compass I bought over 50 years ago.
I don't trust compasses much anymore, except to get a rough idea of what direction I'm looking. When I want to find an accurate heading to a satellite, I use the sun.

Dang it, Bill !! You're dating yourself... But I agree. I just use my compass to get an approximate heading for the dish. The only thing that alters my compass reading is a car parked in the customer's driveway so I keep at least 10 feet away from any vehicles when taking a reading.

kat

[glen4cindy]

I agree with wejones. These compass's look like they would be really accurate. They remind me of military a compass.

Worthless! Mine swings first in one direction then the other, way way off from what is right.

I have my dish set now, but, that compass did not help me in the least.

[rainman]

i yet to see a compass to be dead accurate but it does get you in the ballpark. I have found the sun caculation to be much more accurate so that is what i use the only problem is you got to wait for a certain time of the day and hope the sun stays out.

[Sadoun]

Also a good compass can become a bad compass in no time. All you have to do is set it close to a strong magnetic source and it will be ruined.

[rainman]

Originally Posted by Sadoun

Also a good compass can become a bad compass in no time. All you have to do is set it close to a strong magnetic source and it will be ruined.

and don't forget dropping and banging around in the tool box is not good for them either.

[Sadoun]

Yes that will do it also. That is why the Suunto Tandem compass comes in an Aluminum heavy body and has a nice case to store it.