True South ?

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GaryPen

GaryPen

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OK. This is the first of what promises to be many questions regarding the install of my new system. (It hasn't arrived yet. Just getting a head start.)

It is a motorized system. So, I assume I start by hitting my true south bird, and go from there. Correct?

My longitude is 121.885. So, do I try and get a lock on E9@121 or G10@123. It seems that E9 is closer to my longitude. But, there is only one open channel. G10 is seems to be the most popular sat, and one I'll probably be spending the most time watching.

Also, I would think that using a weaker sat might be advantagious, as I would have to really be precise, and thus ensure accuracy throughout the motor's arc. Should I choose a weak transponder on G10, if any? Can I choose a weak transponder on E9, even if the channels are scrambled?

What do you guys suggest?
 
M

Mr Tony

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Nov 17, 2003
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you always want to use whatever satellite is the closest to your longitude.

Otherwise, the arc wil be off and the farther you get from the middle, the worse the signal will be. Yes there is only one FTA channel on Dish 121 (the Superdish 121 card) that is still what you would use. Some people their TS has no channels on it (like AMC9 at 83W) :)
 
Das Hammer

Das Hammer

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Feb 16, 2006
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Iceberg said:
Some people their TS has no channels on it (like AMC9 at 83W) :)


That would be me. Smack dab in the middle between Brasilsat B3 (no beams shining on the US) and AMC2 (feeds only). Ok, I guess there's an analog test card.

Anyway, just make it easy on yourself like iceberg said. Go with 121. It is a very strong signal and should be very easy to get from your location.
 
SatinKzo

SatinKzo

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May 22, 2004
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How far off can you be from true south before you have problems?
Any suggestions on what to do?
here is my situation:
When I am ready to motorize my setup, the location that is best for most sats is actually horrible for true south, my calculations are that i cannot hit anything between azimuth 160=165 and 195-200, My stationery setup (just got it setup and love it) hits those spots, but isn't good for areas west of 200 az. I hope this makes sense.
 
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Mr Tony

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I am ½ a degree off and it works pretty good.

But what you can do (and this works if your receiver has USALS) is to hook up the motor and set up for USALS and move the motor to a satellite you can tune. Then aim the whole assembly at that satellite and your motor is still set up properly. Its when people use the wrong TS satellite that it becomes an issue
 
GaryPen

GaryPen

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Houston said:
GaryPen,
Been through the same thing, but confirmed my TS with Mag Compass, try checking out www.topo.com, type in your Zip, and read the exact Mag Deviation at the bottom of the page for your loaction.
Also, you might check out some existing posts at:
http://www.satelliteguys.us/showthread.php?p=556715#post556715
GOOD LUCK !
That Topo site seems to sell topogrphic map software products. I don't see a link to any kind of lat/long applet. I used http://terraserver.microsoft.com, and got 121.886.

You mention magnetic deviation. Do I need to add/subtract for mag deviation? I notice that SatFinder has a mag deviation column. I assume that is the column I use to find the proper sat. But, do I need to apply a deviation to my own true longitude? Or, do I match the sat's mag dev long with my true long?
 
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M

Mr Tony

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you subrtact. Anything west of Miss. River is subrratc off of 180 degrees to get where your TS is.

California is around a 12 to 15 degrees off 180. So you aim it east to what dead south is :)
 
GaryPen

GaryPen

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Iceberg said:
you subrtact. Anything west of Miss. River is subrratc off of 180 degrees to get where your TS is.

California is around a 12 to 15 degrees off 180. So you aim it east to what dead south is :)
I have no idea what that means.

Looking at SatFinder, it seems that the Mag Dev column is the one I would use to point the dish, because it corresponds to how I set my E* dishes. What I need to know is how to figure out which sat is my TS. Do I simply match the sat's position (121 for instance) to my true longitude (121.886)?

I probably wasn't clear in my earlier post.
 
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brentb636

brentb636

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Jun 24, 2006
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5 miles N of Saugatuck, Mi
121W is your true south satellite if you live at 121.886 . You will find it about 12-15 degrees East of your compass south, depending on exactly where you live in California. That's where you should point your dish assembly ( estimating at true south) and you can then order the dish via USALS to 121W . It might just barely move. Then you adjust the whole assembly east - west for best signal and lock it down. Next check the dish elevation to see if you can improve the signal quality. Lock it down at the best point.
If your mount is plumb, you should be done. Check it against a far east bird and a far west bird. You should be able to hit them both.
 
GaryPen

GaryPen

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Dot splains it. (I think)

I assume I set the motor physically to zero, and move the entire motor/dish assembly to 163.3deg. (E9 is 178.6 - 15.3 deg mag dev), before doing anything else. Is that correct?

And, then I configure USALS for my location, and use it to move the dish to E9/121 before attempting to adjust dish az/el? Or, should I try and get a signal before using USALS to move to 121w?

Finally, should all adjustments after using the receiver to move the motor to 121 be made to the dish only? Or, to the dish/motor assembly?

Thanks.
 
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Mr Tony

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GaryPen said:
Dot splains it. (I think)

I assume I set the motor physically to zero, and move the entire motor/dish assembly to 163.3deg. (E9 is 178.6 - 15.3 deg mag dev), before doing anything else. Is that correct?
correct

And, then I configure USALS for my location, and use it to move the dish to E9/121 before attempting to adjust dish az/el? Or, should I try and get a signal before using USALS to move to 121w?
yes. Use USALS to move the dish. then move the whole dish/motor assembly to pick up Dish 121

Finally, should all adjustments after using the receiver to move the motor to 121 be made to the dish only? Or, to the dish/motor assembly?

Thanks.
don't touch the elevation on the motor after setting it.
 
SatinKzo

SatinKzo

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May 22, 2004
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That last post and response by gary and iceberg makes it all clear now! Thanks guys!
 
GaryPen

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Iceberg said:
correct


yes. Use USALS to move the dish. then move the whole dish/motor assembly to pick up Dish 121


don't touch the elevation on the motor after setting it.
So, I move the motor/dish assembly for azimuth, but only the dish for elevation?
 
GaryPen

GaryPen

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Thanks, ice. With your guys' help, I should be flying the friendly skies before it gets too late tonight! I might have to leave work early just to get started! (The package arrived just before lunch, btw! I'm psyched!)
 
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Houston

Houston

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Mar 28, 2006
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Magnetic Declination – True, with a Compass

GP,
As I wrote in my PM to you, I apologize for the incorrect Link to TopoZone, the correct one is

http://www.topozone.com/

I had not checked the Link in a while, and find that you need to type in your City and select the State, then it will direct you to the proper Map, where you can read your Magnetic Declination (MD) at the bottom right area of the page. It appears in a little Avatar they use for showing the Declination between True, Magnetic and Grid. You (or others) might click on the Avatar, and read the information, it’s interesting.

Example:
If you type in Houston, then select “TX”, then click on “Place” which is over “Houston”. You will see a MD of –4.062°, I offer this, just so you’ll know you’re headed in the right direction, and able to identify the Avatar/MD I’m referring to.

With proper penance for my error, I looked up the information for you, and find that YOUR location at San Jose, CA. has a MD of (minus) –14.953°. I selected the link for Santa Clara, since it was nearer your Wlong. You can move the Map with the arrows to your exact location, but, that would only change the Wlong less that 0.1°. Not an appreciable amount. The Link you gave for the Microsoft Map, seemed a little more complicated to get, but, that’s your choice.

IF you have an adjustable Declination Ring on your Magnetic Compass, you should set the Pointer/Arrow to the above (San Jose degrees), on the Right side of North. This will provide you with a “minus” reading, when reading the Compass.

You should then set the outer ring on the Compass, where the 180° mark is aligned with the linear axis/line of the Compass frame. Then when placing the Cursor in the center of the “Arrow” (North), it will “mechanically” point you to the True Azimuth of North.

Then you can look straight from South end of the Compass toward North, having the Dish in front of you, and move the Motor/Dish assembly left or right, setting it where the center of your LNB, and the center point of your Dish, are in direct line with the axis/line of the Compass. Then just lock your Motor down on the Pedestal. Assuming you have the Motor Shaft “centered”, and the Dish centered and tightened on it. At this time, the LNB should be vertically aligned and tightened with no “tilt/skew”. The Arc of the Motor Shaft, will compensate for the skew needed, at any given point, when you have the Latitude Elevation set correctly for the Motor.

This should set the “peak/True South” of the Arc of your Motor Shaft, in the right place. Then of course, “electrically” move the motor over to the Azimuth of your nearest Sat, and set the Elevation. I’m sure there may be minor adjustments to both that will be necessary, when getting the Strength and Quality of the Sats at the limits of your FOV. Hopefully you’ve adjusted the Motor Pedestal to be Plumb.

And IF you’re interested, take a look at http://www.satelliteguys.us/showthread.php?p=592999#post592999 Post #6, where you’ll see/click on attachment, of an adjustable Pedestal Motor Mount, which may give you an idea for yours. I do have a more detailed drawing, if you’re interested. (Jack Bolts are more detailed)

I felt compelled in going into detail in the procedure, and I do NOT presume ignorance on your part! Lots of people read these Posts, and this detail may help someone else, later. Hopefully, clear instructions on setting True South, and the other necessary adjustments, will be included with your new Motor.

All you probably wanted, was just a conformation about your Magnetic Declination. :)
I admit, I’m gabby, and over think things, according to Iceberg anyway! :D
 
GaryPen

GaryPen

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Thanks. I used some other site. Plus, SatFinder also provides the info based on zip. Not as accurate as street address. But, I managed to find G10 in stationary mode, and again with the motor.

I've been scanning the skies for a coupla days now. Thanks again!
 
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