Newbie question on mounting dish to motor

[thisBUDsforyou]

I have a dish from 3ABN that is 33" wide and 37 1/4" tall. Bolted onto the back of the dish is an elevation bracket and a sleeve that accepts a 1 5/8" outer diameter pole. The sleeve accepts a pole coming from below. All well and good if I use the universal mount that came with the dish, say attached to a roof.

I also have GeoSat GS-120 motor. The instructions with the motor show the motor arm pointing downwards. The motor arm is the right size to fit the sleeve on the back of the dish, but if you did that the dish would be upside down. So here's my question: do you unbolt the elevation bracket from the dish and flip it upside down for attaching the motor to the dish?

 

[thisBUDsforyou]

Pictures Attached

Maybe with some pictures you can see what I'm talking about.

 

[thisBUDsforyou]

Pictures rotated for better viewing

Let's try this again

 

[Mr Tony]

undo the one bolt on top of the bracket and that slips through the hole on the motor mast...see attached pic

flip dish around first

 

[Mr Tony]

here is my motorized...note the screw in the top that goes through the mast on the motor

 

[thisBUDsforyou]

Well duh, why didn't I think of that! Thanks! Sure helps to have the dish right side up, doesn't it? (see my first picture). On my second picture, any idea what the second set of holes at the bottom of the motor mast is for?

Coupla questions about skew. On my third picture, the top half of the LNB holder has marks on it 20 ... 0 ... 20. I'm guessing these are to set the skew, and I notice the LNB has some similar markings on it as well - so you line up one set of markings with the other to set skew?

I thought I read somewhere that on a motorized setup you just set the skew to zero. Is that right? The skew varies by satellite, but somehow the motor is calibrated to compensate for that, or is it that with a motorized you simply lose the ability to set skew and just have to live with a slightly less than optimal signal strength?

Another question - the main support mast has a little bend in it and I notice on your setup you have the short end of the bend up at the top. On the cryptic little diagram that came with my 3ABN dish they show the short end down at the bottom attached to the plate that bolts to the roof. Does it matter whether you have the short end up or down as long as whatever end is on top is plumb? Or is there a specific reason to have the short end up with a motorized?

One last question about the LNB holder. There is a good one inch of play in terms of how near or far the LNB is from the dish, depending on where you tighten the LNB holder on the neck of the LNB. Does this matter? Or is this another adjustment when you're trying to peak the signal? I thought focal point of the dish was fairly critical so distance of the LNB from the dish would also be critical.

Thanks for your time in answering my questions.

 

[iafirebuff]

Skew set to ZERO for a motorized setup.

How do you like the 3ABN dish? I need to get one ordered as un upgrade

 

[Mr Tony]

Well duh, why didn't I think of that! Thanks! Sure helps to have the dish right side up, doesn't it? (see my first picture). On my second picture, any idea what the second set of holes at the bottom of the motor mast is for?

no clue..but I wouldnt worry. Mine is like that too

Coupla questions about skew. On my third picture, the top half of the LNB holder has marks on it 20 ... 0 ... 20. I'm guessing these are to set the skew, and I notice the LNB has some similar markings on it as well - so you line up one set of markings with the other to set skew?

they should line up at zero since its motorized. The motor will skew the dish

I thought I read somewhere that on a motorized setup you just set the skew to zero. Is that right? The skew varies by satellite, but somehow the motor is calibrated to compensate for that, or is it that with a motorized you simply lose the ability to set skew and just have to live with a slightly less than optimal signal strength?

nope you got it right. The motor skews the LNB as it moves the dish

One last question about the LNB holder. There is a good one inch of play in terms of how near or far the LNB is from the dish, depending on where you tighten the LNB holder on the neck of the LNB. Does this matter? Or is this another adjustment when you're trying to peak the signal? I thought focal point of the dish was fairly critical so distance of the LNB from the dish would also be critical.

Thanks for your time in answering my questions.

I've had it always pushed all the way back from the dish but you may be able to work with it a little bit when aiming the dish

 

[thisBUDsforyou]

Thanks Iceberg!

 

[thisBUDsforyou]

How do you like the 3ABN dish? I need to get one ordered as un upgrade

Well as you can tell I'm no expert but I like the fact that those support arms on either side of the LNB holder make the position of the LNB relative to the dish rock solid, unlike what I've read about some dishes. A word to the wise - when attaching those side arms, bolt them to the dish first, then to the LNB holder. I found that out the hard way.

 

[thisBUDsforyou]

nope you got it right. The motor skews the LNB as it moves the dish

The motor turns the dish to track the arc (azimuth and elevation), but I though skew had to do with turning the LNB relative to the dish (clockwise or counterclockwise). How would a motor control skew?

 

[Wescopc]

When the dish rotates with the motor, because the shaft is aligned with the earth's poles, it tilts the dish to cause the skew.
Bob

 

[Anole]

. . . oops . . .

I think your LNB holder is on backwards.
The LNB should face the center of the dish.

 

[Wescopc]

I think your LNB holder is on backwards.
The LNB should face the center of the dish.

I believe that the arm for the LNB holder should be a bent square tube that is mounted to the elevation bracket on the back of the dish. The LNB arm does NOT use the bottom hole of the dish. I think this is why you had a hard time with the LNB support arms. See the attached picture.
Bob

 

[Wescopc]

On Second Look---

I think your dish didn't come with the square tube - but the support legs (arms) you are using are the tripod supports for the mast. The LNB supports are made from smaller tubing and are longer. That would place the LNB at the proper angle. Check and make sure your dish is flat - you may have pulled it when you used the tripod supports.
Bob

 

[Tron]

That's right, the 3ABN version of this Azure Shine dish has support arms that bolt directly to the reflector. The advantage of this is that you can remove the entire dish and LNBF assembly from the motor without affecting your aim (example, if a hurricane is coming)

EDIT: I just came from a quick check of the satellite farm (since we had some bad weather earlier in the week), and while up there, I took note of the 3ABN dish and the LNBF arm assembly. There are small drain holes located near the ends of the LNBF support arms. On the main support arm, the drain hole needs to be facing downward to allow water that collects inside the arm tube to drain. I now remember noticing that during assembly. I see from your pictures that you have that correctly assembled.

EDIT #2: Bob (wescopc) is right. Upon examining your pics again, it looks like you are using the wrong two support arms for the side supports. The ones you have on the dish belong on the mounting pole. The ones for the dish are longer and smaller in diameter. I'm 99 percent sure that's the whole problem! The supports that go on the pole are shorter, so they are pulling your center LNBF arm out of correct focus.

 

[Anole]

it pays to look twice

I tip my hat and give a bow to the esteemed gentlemen from Oregon and New Orleans.

 

[thisBUDsforyou]

You guys are awesome!

I'll tell you what, that LNB support arm assembly goes together a lot easier if you use the correct parts! :shocked I tried to upload some updated pix but kept getting error messages.

 

[Mr Tony]

file size too big possibly?

 

[thisBUDsforyou]

Pix of Correctly Assembled 3ABN Dish

I don't think it was a file size issue. I tried to upload these same exact three pix this morning with no luck - kept bombing out. Anyway here are pix of 3ABN dish assembled using the correct side support arms for the LNB.