Pointing with Mercury II

Iggy

Member
Original poster
Jun 27, 2007
6
0
Hi, folks,

I am trying to solve a problem: how to (re)point a HughesNet dish without unnecessary trips to the tripod. As will soon become obvious, I am beginning with a vast pool of ignorance, but have researched on the net. Here are some things I think are accurate, and some conclusions which might be true. I am hoping that you can help me from wasting money/energy on an approach which will not work.

Background:

I expect to be living where there are no telephone, DSL, WiFi, cable, power lines, or professional installers. Will move on occasion, by necessity.

I have learned about how RVers manage with a tripod, and have gathered all of the finding programs and pointing instructions I can find. What I need to do (by reason of health) is to automate the pointing process as much as possible.

Equipment: DW7000, .74 plastic dish, 1 watt (assumed --no markings) BUC. Feedhorn is a narrow ellipse with a vertical long axis.

Things I have found out:

Assume a polar mount rotator: STAB HH 120
Assume a plumb pole
Assume a Mercury II FTA receiver.
RE: the Mercury II, Sadoun says:

[FONT=Verdana, Arial, Helvetica, sans-serif]"The M-II is one of the few consumer receivers that will identify the frequency, symbol rate, polarity, FEC and even the PIDS for positive lock to any KU or C-Band satellite"[/FONT]


[FONT=Verdana, Arial, Helvetica, sans-serif]The STAB website claims that if you point the Mercury II at a satellite directly south, the USALS program will be able to find, identify, and lock on, the other geostationary sats.[/FONT]


[FONT=Verdana, Arial, Helvetica, sans-serif][Incidentally, the TopoZone website gives Lat/Long with 4 or 5 decimal places, AND the CURRENT magnetic declination. On the topo of my location, this is more than 3 degrees less than the printed USGS map.][/FONT]



EchoStar 9/Galaxy 23 at 121.0°W lies within 3/10ths of a degree of Due South from my longitude. I am confident that I can "plumb" the pole, and set the HH 120 local latitude, and center it dead south.



Still a little confused about the other two angles (between the HH 120 and the Hughes dish). different sites have different formulas,and none contemplate the Hughes offset dish.



I assume/hope that I can use an "Align A Site" mounted on the top of the dish to set the dish at the proper elevation of Echostar 9 as if it were on a solid pole mount.


So, assuming that the pole is plumb; the HH 120 is aimed dead south; and set to the local latitude; and that the dish is elevated to the proper degree found by using DSSatTool et al; and the skew set at zero; I think:

1. The Mercury II should see the Due South satellite

2. That it could then locate (per USALS) and lock on to the satellite to which my modem will be commisioned (presumably HZN-6K @ 127 degrees W)

[I have seen in several places that a polar HH mount causes (by its "polar" nature) the skew to be correct, for all Geostationaries.]

3 If (when the assigned satellite is located by USALS) I can successfully "peak" the dish with minor adjustments, I assume/hope that, when set up in another location, and assuming a plumb pole, and HH 120 initially pointed dead south, that the dish would maintain the above fine tuning settings, when USALS moves the dish to the assigned sat.

Do "geostationary satellites" all, and always, maintain the same elevation and and skew? Or do they wander a little?

Since the Mercury II can receive DVB signals, and HughesNet transmits in DVB (actully, DVB S2, I think) should/can I route the signal to the DW7000 IP S through the Merc II, or should I move the coax cable to the DW7000?

What I really want to know is whether this idea will not work, so that I do not waste scarce resources, but if so, why it won't work, so I can try to figure out a way which will work.

Thanks in advance for any help you can provide.

IGGY
p.s. I am aware that Hughes does not officially approve of any set up by other than professional installers. This is a matter of actual necessity.

p.p.s. The pole clamp on the Hughes dish appears to be made for a 2 3/8" pole, and the HH 129 rotor is about 2 1/8". Any ideas how and what to insert between them which will maintain concentricity with the rotor?
 
Don't have time to research your equip setup, but for making the mast to 2 3/8" take a piece of chain link corner pole and slip it on the rotor and use self taping screws to secure it. Probably have to use two pieces spliting the first (cuting out about 1/4"). Just an idea cause I had to do this once.
 
Last edited:
Progress (?) Report

All:

Well, it finally DID work; at least long enough to complete the commissioning process. Then it dropped the signal. (Maybe I need to finish the grounding system.)

A couple of things I found out, which might be of use to others:

1. The Mercury II has a user's manual, but you have to figure out most of the functions on your own.

2. The priority for the M II is automatically changing between satellites, when you change channels. This makes it more difficult to do manual moves, when trying to identify satellites. Even though you specifically set "positioners" to off, (in antenna setup) when you select another satellite and begin to select USALS and then GO TO, the receiver begins the move before you request it. Then, when you push GO TO, USALS fails to find the sat. You need to GO TO 0 (South) and then GO TO the new sat.

3. Out of the box, the M II "satellite names" and "known transponders" lists are obsolete. It "sees" TPs not in its lists, not in Lyngsat.com, nor even SatcoDX.com! It also fails to "see" many which are on those lists.

4. It shows L and R rotating polarization as two TPs on the same freq, but one is V and one is H.

5. It apparently cannot "see" Hughesnet TPs. On my commissioning sat, it only recognized ONE transponder (with some encrypted cable channels) but, when I connected the DW7000, I immediately got a 60 + signal, and it passed manual crosspol in about 30 seconds. Of course, I lost the signal immediately after the commissioning ritual.

6. The various "pointing" programs (both in the modem, and on the web) tend to give slightly different pointing values. Worse yet, Magnetic Declination figures vary by up to 4 degrees, depending on the source. Most compasses have marks at 2 degree intervals. The Hughes mounting hardware has degree markings which (even presuming that they are actually accurate) are so coarse that anything less than one degree is problematic.

7. Somebody should publish the Hughes/DirecWay Local Oscillator freq (I used 10750) AND what the 22Khz signal means (turning it ON immediately lost the signal), AND what the "Offset Angle" is for the HughesNet dishes.

Iggy
 
NO progress report -- dazed and confused.

The connection/commissioning in my earlier post was a fluke. :eek: In the daylight, it became obvious that the dish was pointing right in the middle of a large tree. It would still pick up one transponder on that sat (G16/G4 99.0) but nothing else.

So... Moved the dish to a place where I think it will get both due south (121.0) and 99.0. Although repeatability without unnecessary hassle was the point of this experimental rig, there is NO repeatability.

Now, even though it is pointed dead south, and therefore (in theory) within 0.3 degree of Echostar 9/Galaxy 23; it will no longer pick up that south sat, 121.0. In fact, it would pick up nothing. I adjusted the elevation with the SF10S satellite finder, and now it is picking up 11964/H/2921 (signal level 65-70, quality 34-36) This is the "White Springs" channel which Lyngsat says is on Galaxy 27 @129.0. The receiver plays it on my TV, although it is not a good picture, and drops out often.

It is also picking up 12020/H/2359. (Signal Level 70-72, Quality 63-68.) The Mercury II will not recognize anything on this transponder, and I have yet to find it anywhere near 121.0 degrees (dead south).

I am using the same compass, with the same declination set (~17 degrees) in it.

I hope somebody can tell me what I have done wrong. :confused:

Thanks.

Iggy
 
Run down by a Magnetic Bus

After much trial and error, it turns out my problem was a bus. A Mini-bus, to be exact.

When I re-sited the dish, i used the window frame on a parked Mini-bus as an aiming point for true south. Because it is difficult to get a precise bearing from the back side of the dish, I went to the said window frame and shot a back course TO the front of the dish.

Under nominal conditions, a check on the back course will allow one to correct a flawed primary course. Unfortunately, the bus caused enough DEVIATION (about 7.5 degrees) so that the total error was around 10 degrees. :eek: Not a product of clear thinking!

So, now it is on the arc, and receiving the sats it should, where they should be. It turns out that 99.0 is still enough inside the tree that I can only connect to one scrambled cable tv tp, (shown on Lyngsat) and a similar tp with several digital telephony channels, NOT on Lyngsat.

Not sure if I have enough room to re-re-site, in order to miss the tree, and too exhausted to begin.

Although there is a menu way to turn off power to the LNB, (in order to make a clean move to a new sat) during the return to the antenna setup through the menus, a "moving to..." bar appears, sometimes more than once. Since there is no way of telling whether it is actually moving, OR when it stops you often need to "go to 0" to be sure of accuracy.

The dish moves so slowly that I cannot tell if it has only moved a few degrees. I sure could use a certain, positive on/off switch for the LNB/rotor power.

If anybody knows about such a switch, please let me know. Also, if somebody knows the exact LNB offset, for a Hughes (DirecWay, actually) .74 dish, that would help, a lot.

IGGY
 

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