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It is so great to see the effort being put into creating a base of information for motor installs!

If only the scale readings and mechanical tolerances of a HH motor were within a fraction of a degree! The tolerances of the HH motor samples usually is nowhere near a single degree. This discussion is dealing with theory and not a typical installation reality.

Having installed hundreds of HH motors over the years, I stick with the perfectly plum and level post, set the motor angle using the Latitude scale, set the dish elevation angle as per the table provided with the motor. Once the Latitude adjustment is correct and set, lock 'er down...... If the post is not loose or sloppy, the tracking will usually be fine tuned with slight adjustments to the dish elevation setting.

:rant: (Climbing onto soapbox in the busy city center, Brian clears his throat and begins to speak......) "Who cares what satellite is true South?" The process of fixating a newbie on the reception of his True South satellite and aiming for that satellite before anything else is the downfall of many a new installation. It just isn't necessary to locate and lock onto the true south satellite. I know that this will ruffle some feathers, but USALS has changed the way that HH motorized dishes can be installed

Using USALS, drive the motor to an active and appropriate satellite with the receiver placed on an active transponder in the southern sky will result in a successful install. I usually start with any satellite orbital position that is close to the installation Longitude, but that isn't necessary. There is the old school way of trial and error in driving the motor to an approximate heading while correlating the azimuth and declination settings, then there is the USALS method. Both will work, but USALS takes the much of the "geek factor" out of installing the motor!

There is an easy way to install a motorized dish then there is the process using protractors, slide rules, Texas Instrument scientific calculators, reverse calculations, degrees per scale mark, angle finders on every conceivable part of the dish or motor with angle calculations appropriate and applicable to each.

We offered a HH motor install demo to a dozen SatelliteGuys members attending an installation workshop a few years ago and demonstrated that the dish could be put on the arc in less than 30 minutes. It takes more time to Blind Scan the arc of satellites than it does to install the HH motor!

We all have our way of installing gear.... I love the fact that we have a sticky thread dedicated to motor installations!!!

I might just set a temporary dish with a motor and spend some time just to test the accuracy of the 0.6 degrees statement. I am not saying you are not right in terms that there is 0.6 degree factor to consider with other motors (specially the ones that requiere a declination setting), I am just saying that at least with Stab , so far , I have set the Latitude dead on and it works beautifully. I am assuming that when they built their motors they take into consideration this and therefore the scale is mark accordingly.

My problem with your argument is that depending on the motor brand then it might not be the optimal setting for someone using a Stab motor.

This is all speculation of course, I might send an email to Stab asking for clarification on the matter.

BTW out of memory in my last post I made a mistake on the Stab motor Elevation scale tolerance. I said it was 0.1 degree and this is incorrect. It is acctually 1 degree.

My latitude is 43.6 and therefore I always set it halfway between 43 and 44 but to be statistically precise other than 43 or 44 degrees the motor has no accuracy on its scale to guarantee any other value.

In any case this is very interesting information you have given. At least when there is no good programming there is another reason to play with the motorised set up, lol.

hd fan said:

.... I am not saying you are not right in terms that there is 0.6 degree factor to consider with other motors (specially the ones that requiere a declination setting), I am just saying that at least with Stab , so far , I have set the Latitude dead on and it works beautifully. I am assuming that when they built their motors they take into consideration this and therefore the scale is mark accordingly.

Click to expand...

I don't think it's possible that motors take this into consideration, because it isn't always 0.6 degrees. It's different depending upon your latitude. I've made a chart here (I don't guarantee the accuracy but it should be close):
45 0.69
40 0.69
35 0.66
30 0.61
25 0.54
20 0.46
15 0.36
10 0.25
5 0.13
0 0.00

Since most on the forum are in the US, I just call it 0.6 as an approximation. But unless the motor manufacturers sell motors that are designed for different latitudes, then they cannot be taking this effect into consideration. They SHOULD be giving you a chart, such as the "modified" chart at the geo-orbit page (Footprints by Dish Size - Latitude Declination Chart - C/Ku-Band Satellite Listing) . If you look at that chart, you will see that for each latitude they have a column that they call "elevation angle" (but really this is 90 minus elevation, ie the latitude angle). You'll see that for each latitude, the "elevation angle" is slightly more than the actual latitude, similar to adding the 0.6 factor to the latitude in my chart above. So you see, the motor scale really CANNOT take this into consideration. To take it into consideration, you have to put the scale on a setting a bit more than your latitude.

And there is absolutely no question that this "0.6 factor" is real. Basically this 0.6 (or the angle off the chart above) is the difference between the declination for a sat to your south vs the declination of a sat to your east or west. Declination is dependent on your latitude. Ie someone on the equator doesn't use ANY declination, and the further north you are, the more you have to add declination to look down to the equatorial plane. Declination is simply the angle who's tangent is your distance above the equatorial plane divided by your distance to the sat. Your distance above the equator is constant, and depends on your latitude, however the distance to the sat is different for each sat. Sats to your south are closer to you. Sats to your east or west are further away, so the declination will be smaller.
The motor manuals usually simplify things by telling you to set your motor elevation at 90 minus your latitude, ie setting your latitude on the latitude scale, however doing this means that when you peak on your south sat using dish elevation, you'll be setting your declination to the declination of your south sat, and you will by definition be off by the 0.6 angle (off the chart) for your latitude when you aim at a sat to your extreme east or west. The ONLY way to compensate for this effect is to instead use the modified declination/modified latitude setting, which basically uses the declination of a sat to your east/west and compensates for sats to your south by decreasing the elevation (increasing latitude setting) by the 0.6 degree factor. This factor is essentially pro-rated across the arc because elevation adjustments have no effect on sats to your east or west, and proportionally more effect the closer you get to south.

hd fan said:

My problem with your argument is that depending on the motor brand then it might not be the optimal setting for someone using a Stab motor.

Click to expand...

You need to take this into consideration with all mounts, whether small H-H motors or big C-band mounts. And as mentioned above, it cannot be taken into consideration by the manufacturer shifting the latitude scale, unless they sold different motors or mounts for different latitudes, which they don't. But if you are un-sure about what the motor scale really means, then you shoud use an inclinometer to set the motor instead of trusting the scale. Then there would be no question.

hd fan said:

This is all speculation of course, I might send an email to Stab asking for clarification on the matter.

Click to expand...

I'd be interested in what they say. THey're obviously giving you a chart which is just an approximation, and they just assume that most people won't notice the error.

hd fan said:

BTW out of memory in my last post I made a mistake on the Stab motor Elevation scale tolerance. I said it was 0.1 degree and this is incorrect. It is acctually 1 degree.

Click to expand...

Right. And it's obviously pretty hard to set this angle to accuracies smaller than 1 degree, and for most dish/receiver combinations, you can't tell the difference with errors that small. With bigger dishes, such as with a good 10' dish doing Ku, you can easily see the effect. I think that these motor manufacturers just tell you to use your latitude because it's easier, and the resolution of a 30" dish on Ku is so wide that you can't tell the difference when you're off by 0.6 degrees. But the bigger the dish or the the higher the frequency, the more important this factor becomes.

hd fan said:

My latitude is 43.6 and therefore I always set it halfway between 43 and 44 but to be statistically precise other than 43 or 44 degrees the motor has no accuracy on its scale to guarantee any other value.
.

Click to expand...

The situation when this factor becomes more important would be for people who say are at 43.4. I've seen posts from people who say that they just rounded 43.4 off to 43, when in fact the acual number they should be using would be 44. Ie by rounding off, they're increasing the error up to a whole degree. In your case, by splitting the difference and only off by about 0.7-0.8 degrees, and if you had rounded off to 44, you would have been closer. Basically, I realize that you really can't set these motors very accurately via the scales, but it helps if you at least start out trying to set the proper value, instead of a value that is off by the better portion of a degree.

SatelliteAV said:

It is so great to see the effort being put into creating a base of information for motor installs!

If only the scale readings and mechanical tolerances of a HH motor were within a fraction of a degree! The tolerances of the HH motor samples usually is nowhere near a single degree. This discussion is dealing with theory and not a typical installation reality.

Having installed hundreds of HH motors over the years, I stick with the perfectly plum and level post, set the motor angle using the Latitude scale, set the dish elevation angle as per the table provided with the motor. Once the Latitude adjustment is correct and set, lock 'er down...... If the post is not loose or sloppy, the tracking will usually be fine tuned with slight adjustments to the dish elevation setting.

:rant: (Climbing onto soapbox in the busy city center, Brian clears his throat and begins to speak......) "Who cares what satellite is true South?" The process of fixating a newbie on the reception of his True South satellite and aiming for that satellite before anything else is the downfall of many a new installation. It just isn't necessary to locate and lock onto the true south satellite. I know that this will ruffle some feathers, but USALS has changed the way that HH motorized dishes can be installed

Using USALS, drive the motor to an active and appropriate satellite with the receiver placed on an active transponder in the southern sky will result in a successful install. I usually start with any satellite orbital position that is close to the installation Longitude, but that isn't necessary. There is the old school way of trial and error in driving the motor to an approximate heading while correlating the azimuth and declination settings, then there is the USALS method. Both will work, but USALS takes the much of the "geek factor" out of installing the motor!

There is an easy way to install a motorized dish then there is the process using protractors, slide rules, Texas Instrument scientific calculators, reverse calculations, degrees per scale mark, angle finders on every conceivable part of the dish or motor with angle calculations appropriate and applicable to each.

We offered a HH motor install demo to a dozen SatelliteGuys members attending an installation workshop a few years ago and demonstrated that the dish could be put on the arc in less than 30 minutes. It takes more time to Blind Scan the arc of satellites than it does to install the HH motor!

We all have our way of installing gear.... I love the fact that we have a sticky thread dedicated to motor installations!!!

Click to expand...

Brian,

Excellent explanation and description that you have relayed here. I agree with your analysis and I have proven that your time estimate to align to the arc is easily accomplished. This is providing that you are not including setting up the mast, concreting it in and counting the time to haul all the equipment around to prepare to get underway.

If you don't count all this time, you can truly align to the arc in less than 30 minutes for certain. 7-15 minutes if you really try hard and have a set pattern to follow. Knowing the satellites and transponders which are strong and active in the location where you are setting up the dish is key. That allows you to use data and information from memory and not have to look up tables and calculate angles and all that matter.

Every bit of information and advice we share here, can only improve our setups and reduce our set-up time. So, we are definitely doing a good thing to discuss and post new ideas and information.

RADAR

Thanks so much BJ for all the valuable info. I will defineatelly be using this adjustment in future Stab motors installations. Sometimes being Stubborn has its merits, lol.

Electronic Inclinometer on sale

Stumbled on this thread and it inspired me to check the latitude setting on my setup. I used an electronic inclinometer I bought recently from Rockler for $30 on sale. It's for use in my shop but it works well for this too. It's supposed to be accurate to .1 degree and a quick check bears that out. I used a 6" steel machinist's square on the motor base and read the elevation off that. According to the Latitude + Elevation +0.6 formula I'm off about .15 degree - think I'll leave it alone. Right now I'm getting sats from 83W to 129W, though some of them are low Q - I'll do a little dish tweaking once I rig up a fine adjustment scheme for the dish elevation - just loosening the bolts and moving it in small increments is too iffy for me - sometimes it jumps right past where I wanted it and sometimes it won't move at all - also pushing on it flexes things a little and it's too hard to guess how far to go. Whew that was a long sentence.

John

Excellent read, guys....I used the Sadoun website on setting up my motorised dish, but this thread has really been an education. Thanks for taking the time to share your knowledge (everyone)....much appreciated.