True South vs True South *satellite*

[gpflepsen]

i have installed over 50 SG9120's, never had one scale incorrect, the problem must be on your end

Powermax SG9120Bs?

 

[Mikey11]

The scale on the side of this Powermax motor is absolutely printed off several degrees. I can assure you everything is leveled, including the bracket and the pole, thank you. Do a search around here, and you will find others reporting the same thing about the scales being printed off.

i have installed over 50 SG9120's never had one scale that was incorrect, the problem must be on your end

By the way, I've been using and installing dishes for 30 years

40 years here, i have you beat

 

[Mikey11]

Powermax SG9120Bs?

yes

 

[Lone Cloud]

Not to get off topic, but a basic compass reading is necessary before planting any dish. If a magnetic compass is reading 180 degrees south, isn't a true south heading entirely dependent on the location due to magnetic declination? I know in my location it is +5. I never see anything on this forum addressing this issue. Another thing that has always been puzzling to me, folks located in the southern hemisphere, do their dishes point north? Assuming all satellites are in stationary orbit above the equator.

I don't use a compass. I think all you really need is an inclinometer, although a lot of guys misread them as I did once.

A compass, adjusted for magnetic deviation, is useful to get the general direction of due south, but probably not necessary. If you bring your receiver and little tv out to your dish, as I did early on, you can get it pretty close. If you have a little dish and USALS motor, you've already set your dish for the satellite you are going for, and have the elevation pretty close also. In that situation, with your receiver set to a hot transponder, you slowly swivel your mount and dish on your pole until you get a signal.

If you have a big dish, it's a little different. In that situation there is no automatic adjustment of the dish when your southernmost satellite is off a couple of degrees. You have to set that yourself. In my case, for instance, my longitude is .6 degrees west of my southernmost satellite. So I get zenith and then move my dish about eight or nine counts east. Then I set my receiver to a hot transponder and channel and do the swivel thing until I get a signal.

So a compass can be helpful, but it isn't necessary

 

[primestar31]

i have installed over 50 SG9120's never had one scale that was incorrect, the problem must be on your end

Ok, if you say so. Now since you've installed over 50 of them, you should be willing to do a write-up showing exactly how all the rest of us should do it. That way you pass on your knowledge, and help out all the rest of us who have found the scale on the motor to be wrong. Believe me, this write-up is seriously needed, and if you can do it, please do so. If you've already done one, please point me to the post.

If you do this, I will completely over-haul my installation according to your instructions, and then we will see.

Personally, I suspect that the last few batches of Powermax sg9120b's were clones, and they messed them up. Not sure when the last time was that you installed one, but mine was in July of this year, (bought off Ebay) and I think all the others reporting this also had one this year.

I leveled everything, and it was still off. I re-did it 5 times just to make sure, and even made a fine elevation adjustment screw for the back of my dish. I finally decided to do it using the inclinometer, and that's when I realized that the scale on the side of the motor was wrong. I found installing this motor to just be horrible, compared to a standard polar mount installation.

 

[T4Runner]

This conversation reminds me of the first motorized STAB HH120 I mounted for KU. I was going crazy trying to adjust it for the Clark belt and could not get it accurate. Then I read somewhere that just because the post is plumb does NOT mean the motor bracket is plumb.

It wasn't. I plumbed the motor bracket on the pole and the dish tracked the arc perfectly. Now that motor several years later is just sloppy gears..

 

[gpflepsen]

i dont really believe your scale was inaccurate, i think your motor bracket was probably not level,

most people assume that their motor is level just because their mounting pole is level, this is incorrect and should never be assumed,

My experience shows this to be good advice.

after you have aimed the motor and tightened all the bolts up you should use a level to make sure the motor itself is level, just because the mounting pole is level that does not mean the motor will be,

Why is this? If you think about it, the Elevation or Latitude scale gives a relationship between a plumb pole and a "level" motor. If you've found the need to not trust that a plumb pole translates to a "level" motor, this immediately calls the stamped scales into question for one of the two motor axis. If the pole needs to be angled fore or aft to compensate for the motor and make the scales "correct", the scales are inaccurate.

if the motor is not 100% level, the mounting pole should then be re-adjusted to compensate, to make sure the motor itself is level, this may mean the pole is not level, but that doesnt matter, its the motor itself that needs to be level, not the pole

 

[Mikey11]

Ok, if you say so. Now since you've installed over 50 of them, you should be willing to do a write-up showing exactly how all the rest of us should do it. That way you pass on your knowledge, and help out all the rest of us who have found the scale on the motor to be wrong. Believe me, this write-up is seriously needed, and if you can do it, please do so. If you've already done one, please point me to the post.

If you do this, I will completely over-haul my installation according to your instructions, and then we will see.

Personally, I suspect that the last few batches of Powermax sg9120b's were clones, and they messed them up. Not sure when the last time was that you installed one, but mine was in July of this year, (bought off Ebay) and I think all the others reporting this also had one this year.

I leveled everything, and it was still off. I re-did it 5 times just to make sure, and even made a fine elevation adjustment screw for the back of my dish. I finally decided to do it using the inclinometer, and that's when I realized that the scale on the side of the motor was wrong. I found installing this motor to just be horrible, compared to a standard polar mount installation.

you probably had a clone 9120......

i will keep it as short as possible...leaving out certain obvious details such as wiring and lnb etc.....

i mount a very secure pole 100% level, going into a brick/concrete wall when possible as i feel that is the most secure installation, when i mount a pole i can hang my entire body weight off it without it moving, i have never had one call back for a dish/motor that has moved or become mis-aligned,

i set the motors latitude scale to the latitude of the installation, and mount the dish on the motor tube making sure it is mounted square/straight at zero degrees,

i put the whole assembly on the pole, sometimes i mount a c-clamp or hose clamp just below the motor assembly on the pole, this prevents the assembly from sliding down the pole during aiming,

next i drive the motor using USALS to the southern most satellite that i am aiming with, then i aim the dish,

AIMING......

when making horizontal adjustments, i move the entire dish/motor assembly on the pole, when making vertical adjustments i move the dish only, not the motor,

after i have aimed the selected satellite for best possible signal quality i tighten everything up,

next i check to make sure the MOTOR BRACKET is 100% level, if it is not i will adjust the MOUNTING POLE until the motor bracket is level, (its the motor bracket that needs to be level, not the pole)

then i may repeat the process starting above at "aiming" 2-3 times,

when i am happy with the quality of the southern most satellite, and i am SURE the motors bracket is 100% level i will check a satellite at each end of the arc, which 99% of the time is also 100% perfect,

i might make very fine adjustments to the dishes elevation at the ends of the arc,

done.....

 

[Mikey11]

Why is this?

because a motor bracket can twist after the bolts are tightened, if this happens, the motor will not be level, even though the pole is,

 

[primestar31]

What have you found on the degrees calculation to set Declination between the motor tube and the dish elevation scale? The booklet with the motor says 40degrees - (minus) Declination angle (which is 6.6 in my area) or 33.4 degrees. Other postings here including from Brian of SatelliteAV, said to use 30 degrees minus declination = 23.4 for me. My 3ABN dish couldn't be set above even 20 degrees and hit the sat, until I adjusted the motor elevation using the inclinometer. Motor bracket and pole were dead-level already, I made sure of that

Once I reset the motor using the inclinometer, I was able to raise my dish (I'm remembering here) from something like 18-19 degrees, to the 23~ degrees the calculation says it should be. I then was able to hit all the sats nearly dead-on, from East to West. I have now since then had to move my KU dish pole (ground pole) due to the need for installing a larger c-band dish. and that just was too close to my ku dish. I didn't want any crashes together when the KU dish moved on channel changes. Where the KU dish is right now it is off a bit, and I have to redo it again. It's been raining so much lately, I just haven't had a chance as of yet.

 

[gpflepsen]

because a motor bracket can twist after the bolts are tightened, if this happens, the motor will not be level, even though the pole is,

I think we are talking mountains and mole hills here. You seem to be talking about tweaking fractions of a degree due to stresses and strains. I'm talking about things that are just not made correctly. For example, my Elevation and Lattitjude scales are not correct. Heck, they are not even complimentary i.e. they would add to 90 if they were correct.

 

[primestar31]

I think we are talking mountains and mole hills here. You seem to be talking about tweaking fractions of a degree due to stresses and strains. I'm talking about things that are just not made correctly. For example, my Elevation and Lattitude scales are not correct. Heck, they are not even complimentary i.e. they would add to 90 if they were correct.

Yeah, when I discovered that on mine when I finally grabbed my inclinometer and noticed it, I thought "what the heck?" But it was the first of this sort of motor I've ever installed, so thought maybe I was missing something, and that they should be that way.

 

[Mikey11]

I think we are talking mountains and mole hills here. You seem to be talking about tweaking fractions of a degree due to stresses and strains. I'm talking about things that are just not made correctly. For example, my Elevation and Lattitjude scales are not correct. Heck, they are not even complimentary i.e. they would add to 90 if they were correct.

i suppose its possible for SOME to be marked incorrectly, in order to prove that wrong i would have to go around the entire world checking every single motor,

all im saying is out of the 50+ i have installed, i have never had one marked incorrectly, 50 for 50 is a pretty good percentage to me,

maybe the ones marked incorrectly are clones?

 

[Mikey11]

Other postings here including from Brian of SatelliteAV, said to use 30 degrees minus declination = 23.4 for me.

this sounds correct to me....when i do an install the dish elevation scale is normally around 23 degrees once everything is said and done

 

[gpflepsen]

maybe the ones marked incorrectly are clones?

My struggle is trying to be educated to know what is a clone and what is genuine. It's a crap shoot it seems.

 

[flyguyj]

Mikey I liked your detailed instructions for mounting and aiming the dish. Coincidentally, I had already done (more or less) exactly what you described over the weekend. Both ends of the arc are strooong, but a handful throughout the middle have lesser, or even sporadic, signal quality. What gives? These are on the transponders they default to when I motor over to them through the menu, but usually (with the exception of 1 or 2 sats), the signal steadies and goes back into the 70s again once you click a couple of transponders in...

Is it something I'm doing wrong or does my dish need tweaking? I figured I had it pretty well doped out if 12-14 out of the 18 I'm testing for signal are pretty strong (solid 70s with no jumping), and only a handful are twitchy and finally settle down on the 3rd or 4th TP, and then only like 2 sats just have poor quality all-around. Thoughts?

 

[Mikey11]

Mikey I liked your detailed instructions for mounting and aiming the dish. Coincidentally, I had already done (more or less) exactly what you described over the weekend. Both ends of the arc are strooong, but a handful throughout the middle have lesser, or even sporadic, signal quality. What gives? These are on the transponders they default to when I motor over to them through the menu, but usually (with the exception of 1 or 2 sats), the signal steadies and goes back into the 70s again once you click a couple of transponders in...

Is it something I'm doing wrong or does my dish need tweaking? I figured I had it pretty well doped out if 12-14 out of the 18 I'm testing for signal are pretty strong (solid 70s with no jumping), and only a handful are twitchy and finally settle down on the 3rd or 4th TP, and then only like 2 sats just have poor quality all-around. Thoughts?

it sounds like your azmuth is correct, so leave that alone,

it sounds like the motor itself is aimed slightly too high, or slightly too low, meaning your arc is too high or too low,

aim the motor (using the receiver) to a satellite near the top of the arc, and have somebody watch the quality scale while you go out to the dish, without loosening any bolts grab the top of the dish and push in and push out, like your trying to move the dish up or down,

this will determine which way you are off by seeing when the signal quality increases,

 

[flyguyj]

Ok, I'll try that this weekend ... latitude is set on the motor, so should I only be adjusting the elevation of the dish, or should I adjust it at the motor itself?

 

[Mikey11]

Ok, I'll try that this weekend ... latitude is set on the motor, so should I only be adjusting the elevation of the dish, or should I adjust it at the motor itself?

it sounds like the latitude adjustment on the motor is not correct, it either needs to be slightly higher, or slightly lower,

after setting that you will also need to re-adjust the dishes elevation setting