There's so little straight section of the pole exposed that I'm wondering if I can take level readings off the sides and back of the SG2100 to ensure it is plum. I measured the mast and set it slightly high so that the weight of the dish and motor might pull it down level, but I'd like to measure it with it all in place. Wondering if anyone has ever done it that way? I don't want to assume that I can take accurate readings off the top of the pipe, as it may not be exactly square.
Measuring plum off motor housing?
- Thread starter TiminMb
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TiminMb - I am in agreement that anything we can do to verify plumb, due south orientation etc at various points in the alignment chain are all good.
Looking at my own SG2100 I would not see any point in trying to measure plumb off the housing or back, too many curves and other things getting in the way.
One of the critical results we are after is a correct alignment of the central axis of the tube. I have never done this, but you might find an insert long enough to get a declination reading from this axis before and after the dish is mounted.
In my own case I prefer a post/mast that is fixed but can be tensioned according to need. That way I can add my level to the mast any time I need to check whether it is still plumb or not, making adjustments if required.
Looking at my own SG2100 I would not see any point in trying to measure plumb off the housing or back, too many curves and other things getting in the way.
One of the critical results we are after is a correct alignment of the central axis of the tube. I have never done this, but you might find an insert long enough to get a declination reading from this axis before and after the dish is mounted.
In my own case I prefer a post/mast that is fixed but can be tensioned according to need. That way I can add my level to the mast any time I need to check whether it is still plumb or not, making adjustments if required.
The problem I'm running into is that when I set my dish up for my true south sat, when I get further east and west the dish is aiming too high. That makes me think the pole is tilted forward(?) slightly, flattening the arc. But there is no where to measure the gooseneck pole when the motor is mounted to it.
I used to get all the sats in the arc, right out to Amazonas. I wonder if my SG2100 is wearing out from the weight of my dish? Well, before I jump to that conclusion, I want to know that the pole is plum with the weight of the dish and motor mounted.
I used to get all the sats in the arc, right out to Amazonas. I wonder if my SG2100 is wearing out from the weight of my dish? Well, before I jump to that conclusion, I want to know that the pole is plum with the weight of the dish and motor mounted.
Thinking about this some more. Are you suggesting taking a measurement off the stem coming out of the motor? If so, do you set it to the degrees that the motor is pitched back?
Actually I was thinking of something rather simpler, yes taking the measurement off the stem but doing it once with it pointed south and the dish off and then again with the dish on to see if there is a difference. But it sounds as if you don't have room to measure.
I'm having difficulty imagining your motor mount and why so little of the pole is available for plumb verification. Since there is enough length to attach a motor, can you take a regular level and attach perpendicular arms to it that would allow it to touch the pole above and below the motor and give you some idea of plumb?
Since the problem is at the ends of the arc this might not be helpful since more likely you will run into slop (looseness in the motor) issues, which have been discussed before.
I'm having difficulty imagining your motor mount and why so little of the pole is available for plumb verification. Since there is enough length to attach a motor, can you take a regular level and attach perpendicular arms to it that would allow it to touch the pole above and below the motor and give you some idea of plumb?
Since the problem is at the ends of the arc this might not be helpful since more likely you will run into slop (looseness in the motor) issues, which have been discussed before.
With this SG2100 on a Fortec gooseneck pole, there is just barely enough straight section to mount the motor. The top U bolts are within 3/8" of the top of the pole, and the bottom rest just about where it starts to curve. It leaves you with no area to place a level against as its all occupied by the two u bolts and motor. Would be much simpler if it was all straight pole.
I don't know what your mounting situation is, but it would seem that if at all possible it would pay to dump the gooseneck and go with a regular straight pole, at least then you would have much more control over plumb of the pole and control over the motor, particularly at the ends of the arc.
Spent a good part of the day climbing up and down from the roof. I'm certain I have the pole perfectly plum, and with the weight of the dish. I've ran the dish east and west and the dish stays vertical. The bad news is that I can't get much east of my location. I really want AMC6 and lost it ever since I switched to a heavier lnbf, the Xtreme II.
I'm finding that when I set my elevation on my true South Sat, IA5 at 97W, its too high when I turn the motor to G10R at 129W. I'm considering playing with the elevation setting on the motor and lifting the motor higher so it has a sharper arc so that it drops off faster off centre to match the elevation at G10R. I currently have it set at a compromise setting that gets me both, but neither at their highest peak.
I'm going to do another test when I get some time, and that is to turn the motor to 97W by USALS, and that should make the motor stem point due South, and it should make the stem perfectly vertical when measured from East and West. I'm wondering if something is screwed up and causing the arc to be off, even though my pole is plum. I bought a small level that fits onto the exposed part of the pole at the motor mount and the pole is as level as level can get. I'm wondering if either my motor is worn out, or the mount is bent and the motor is sitting crooked on a plum pole.
I'm finding that when I set my elevation on my true South Sat, IA5 at 97W, its too high when I turn the motor to G10R at 129W. I'm considering playing with the elevation setting on the motor and lifting the motor higher so it has a sharper arc so that it drops off faster off centre to match the elevation at G10R. I currently have it set at a compromise setting that gets me both, but neither at their highest peak.
I'm going to do another test when I get some time, and that is to turn the motor to 97W by USALS, and that should make the motor stem point due South, and it should make the stem perfectly vertical when measured from East and West. I'm wondering if something is screwed up and causing the arc to be off, even though my pole is plum. I bought a small level that fits onto the exposed part of the pole at the motor mount and the pole is as level as level can get. I'm wondering if either my motor is worn out, or the mount is bent and the motor is sitting crooked on a plum pole.
Two things come to mind, and your heavy LNB is a clue.
The heavy LNB may bend the LNB arm a little, and it may spring back some at the extreme east and west of the travel.
In the middle (due south), the bend may be the worst.
This is alleviated by having support struts on some dishes, so the LNB is held by three arms, instead of one.
Solutions are simple: more support arms (hard to do) , or lighter LNB: the Xtreme I comes to mind.
As for knowing if the top of your post is plumb, here is a picture of a bubble level that clips into the end of the mast.
When I find mine (came with a DirecTV dish), I'm gonna put it in my 36" Fortec mast and tune up my motor and dish.
My Invacom LNB is heavy, too.
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I'm going to eliminate the possibility that the motor is no longer zeroing at true south setting. I'll motor it to an imaginary sat at my longitude and see if the shaft and housing line up at zero. Some old posts indicate this problem can occur.
The dish I'm using has three support arms. Its possible the plastic holder is bending a little. I am also supporting a circular lnb on the arm. But that's nothing new.
The dish I'm using has three support arms. Its possible the plastic holder is bending a little. I am also supporting a circular lnb on the arm. But that's nothing new.
Yes, that was the problem. USALS fully working now.
The motor when zero'd to my longitude, read approx 5 degrees off zero on the stem to housing markings. I zero'd it manually up on the roof, hit reset, then repeaked the signal by moving the motor mount to pole axis. I'm getting all the olds sat's again, and with USALS. Even getting a couple of PBS's on AMC3 now. Its better than ever I'd have to say.
So there you have it. SG2100 while its a good motor, the zero issue needs to be checked when things go askew.
The motor when zero'd to my longitude, read approx 5 degrees off zero on the stem to housing markings. I zero'd it manually up on the roof, hit reset, then repeaked the signal by moving the motor mount to pole axis. I'm getting all the olds sat's again, and with USALS. Even getting a couple of PBS's on AMC3 now.
Its better than ever I'd have to say.So there you have it. SG2100 while its a good motor, the zero issue needs to be checked when things go askew.
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Anole, you can find those bubble levels at Lowes, they're only a buck or two. I was going to pick up a couple the last time I was in there, but they were closing and I was trying to get the supplies I needed for my OTA DTV antenna.
Yep... bubble levels are very cheap. I found my little one that I use at Walmart for about a buck or two. I like it since it's small enough to fit in my pocket as I climb the ladder to the roof. Also... if your pole isn't straight at the top... and is jagged for whatever reason, you may consider trying out a laser level in addition to a bubble level?
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