SG2100 Positioner Heart Surgery

[jerryt]

I experianced a lot of problems with the SG2100 positioner not responding after turning to a couple of different satellites. Had this problem with two separate Twinhan PCI cards in separate rooms and also with a Stab HH90 positioner.

So I decide to perform a modification to the SG2100 and supply the power for the motor externally. I hope this modification will show if the problem is a weak power supply on the twinhan cards (Which is what I suspected from my reading on other forums). After the modification, the Positioner operates much better with the power now coming from a separate 12v nonregulated 500ma power supply (puts out 16.5 volts with motor running). I suspect that there is some voltage drop to the motor when power is supplied by the foil on the curcuit board. After reinstalling the motor and programing the satellite positions this weekend all apears well. The positioner never once failed to respond.

 

[Cascade]

jerryt, I had the same problem with a DBS LNB when I hit 110 and 119 which is one of the reasons I took the DBS LNB out of my system.
Which sats are doing it for you?

 

[jerryt]

I have had a DBS LNB in the center and never had the problem. Then when I have my Linear 0.6db in the center and tuned PBS HD, watch out, problems. I have measure the current draw of each component in my system and I know that my 0.6db linear LNB draws more current, But it works better than my Zinwell 0.3db LNB. So at the moment the dish is working well with; SG2100, switch, 0.6db Linear LNB, DTV Circular LNB.

 

[Cascade]

My theory is that it has something to do with the co-ax being saturated with signal (strength or symbolrate) and the diseqc commands getting lost in the mix somewhere along the line.

Of course I may be totally wrong.

 

[truckracer]

sg problem

Hey guys, I have two sg-2100 motors. One is connected to a coship 2300B diseqc 1.2 receiver and the other connected to a pansat 2500 usals receiver.

The Pansat about every three months or so looses sync with the motor.
Then I have to go into the "antenna setup" menu, tell it to go to reference point or "0" degrees. When I go out and look at the pointer on the motor, it is usually about 4-6 degrees west of "0". So I use the manual button and line up the motor with "0" degrees. Next I take a paperclip and reset the motor, then re-boot the receiver.

This does the trick for about 3 months.

On the Coship 2300, it just has fine tune east/west buttons on the remote and I can nudge the dish a little either way and then update the position after checking the signal meter.

From what I understand about diseqc commands, the receiver just barks out the command over the coax and the motor itself has a small cpu that interprets the command, closes a circuit, the motor starts to move and the cpu counts pulses from a reed switch until the motor gets into the proper position. But I do not think the motor's controller actually "talks" back to the receiver. I think this is sort of the problem with diseqc commands. It would be like telling your kids "clean your room" but you never look to see if they did it.

I have had bad diseqc switches in the past and one switch with a dead port. I always power down my receivers before making or breaking connections, but nevertheless I have had switches go down. I wish diseqc systems had diagnostics and the receivers could troubleshoot problems.

I do know that different versions of firmware from receiver manufacturers have different bugs and flukes with diseqc. I purchased a Fortec Ultra Lifetime receiver when they first came out and paid $259.00 plus shipping. It never would ever run a diseqc motor. It would do all kinds of crazy stuff when trying to setup usals. Once it even started just moving the dish east to west continuously. I contacted the dealer from where I purchased and they told me to go to fortec star's website, download the newest firmware and upload it to the receiver. If that did not work, then send it back for a new one. I did the upgrade and it was successful. This somewhat repaired the problem except now that diseqc worked properly it started loosing antenna settings if you tried to program more than one satellite. It would loose the lnbf low freq setting, satellite names would have mispelled names and misplaced symbols in the spelling, the receiver would power itself off for no reason and constantly lock up with a frozen image on the screen.

I upgraded the firmware again but never used this receiver for running any diseqc componets, now I slave it to my orb-7500 c-band receiver and use it as a dvb receiver on my big dish. It works fine for that.

 

[jerryt]

My theory on the positioner having problems is; Current overload with the Twinhan card.

I believe that when the current requirements reach a certain level, the twinhan card cycles the power. The positioner sees the cycle of power as a fault and stops responding until the power is completely removed for a few minutes.

As far as getting out of syn. There is a position sensor in the SG2100 in addtion to the pulse counter.

By the way I am getting 45 steps to one degree of movement with MyTheatre's Position Console, with 20 steps to fine tune the signal.

 

[jerryt]

My theory is that it has something to do with the co-ax being saturated with signal (strength or symbolrate) and the diseqc commands getting lost in the mix somewhere along the line.

Of course I may be totally wrong.

Simple test would be to cover the LNB when the positioner is not responding.

 

[timmy1376]

How about the cable? A friend told me today he would like to stay away from copper coated center wire and to make sure if you got cable, get all copper center wire.

 

[Rick in MD]

I do know that different versions of firmware from receiver manufacturers have different bugs and flukes with diseqc. I purchased a Fortec Ultra Lifetime receiver when they first came out and paid $259.00 plus shipping. It never would ever run a diseqc motor. It would do all kinds of crazy stuff when trying to setup usals. Once it even started just moving the dish east to west continuously. I contacted the dealer from where I purchased and they told me to go to fortec star's website, download the newest firmware and upload it to the receiver. If that did not work, then send it back for a new one. I did the upgrade and it was successful. This somewhat repaired the problem except now that diseqc worked properly it started loosing antenna settings if you tried to program more than one satellite. It would loose the lnbf low freq setting, satellite names would have mispelled names and misplaced symbols in the spelling, the receiver would power itself off for no reason and constantly lock up with a frozen image on the screen.

I upgraded the firmware again but never used this receiver for running any diseqc componets, now I slave it to my orb-7500 c-band receiver and use it as a dvb receiver on my big dish. It works fine for that.

To perhaps make your use of the Fortec Star Lifetime Ultra a little better, I just asked this question on the board a week or so ago, and got some great assistance. Might help with your problems, I know it has helped with mine.

Rick

http://www.satelliteguys.us/showthread.php?t=74294

 

[jerryt]

Follow up with my positioner motor modification


Both my SG2100 and Stab HH90 positioners were intermittent and unreliable with both my Twinhan 1020 and 102 PCI cards. The positioners would only move for the first couple of commands and then quit. I would have to restart the computer or reset the motor or both to get it working again.

Tested the theory that "the Twinhan cards can not provide enough current for the motor in the positioner".

Powered the motor of the positioner with an external 18 volt power supply.

Results after a couple of weeks??????? Works perfect!!! Never missed a command and moves faster. (Since before the modification the motor sometimes would be moving on a 13V channel and now the motor always sees 18V).

 

[jerryt]

Step by step guide

Posted a powerpoint file showing step by step how to modify a SG2100 positioner to operate from an external power supply.

hxxp://groups.yahoo.com/group/skystar2/files/Positioner%20heart%20surgery.ppt

Change xx to tt

 

[beeb]

My theory is that it's not the DVB card that does not supply enough power, but the power supply of the PC. I have SkyStar2 and Twinhan 1020a and they have always moved the positioner without any problems. For more than a year I've never reset the motor or the DVB cards/receivers. I don't use USALS, btw, with my Pansat 3500s.
The fact that jerryt had problems with the power from 2 cards pretty much proves that it's the PC power supply or perhaps the motherboard that's the culprit.

 

[jerryt]

My theory is that it's not the DVB card that does not supply enough power, but the power supply of the PC. I have SkyStar2 and Twinhan 1020a and they have always moved the positioner without any problems. For more than a year I've never reset the motor or the DVB cards/receivers. I don't use USALS, btw, with my Pansat 3500s.
The fact that jerryt had problems with the power from 2 cards pretty much proves that it's the PC power supply or perhaps the motherboard that's the culprit.

I had the problem in two separate computers (with Twinhan cards one 1020 and one 102g), but maybe Satellite PC's need bigger then normal power supplies?

 

[beeb]

I'm using Zalman 350W.

 

[sharris]

My theory is that it's not the DVB card that does not supply enough power, but the power supply of the PC. I have SkyStar2 and Twinhan 1020a and they have always moved the positioner without any problems. For more than a year I've never reset the motor or the DVB cards/receivers. I don't use USALS, btw, with my Pansat 3500s.
The fact that jerryt had problems with the power from 2 cards pretty much proves that it's the PC power supply or perhaps the motherboard that's the culprit.

If the twinhan used a seperate port on the computer i..e, usb or serial I would agree, but in this case of course thats not the case. It is a voltage problem right from the twinhan. I've heard the nexus and haupguage or more reliable for this and of course more expensive.

 

[beeb]

If the twinhan used a seperate port on the computer i..e, usb or serial I would agree, but in this case of course thats not the case. It is a voltage problem right from the twinhan. I've heard the nexus and haupguage or more reliable for this and of course more expensive.

Well, if that's true, I am a big exception. My Twinhan 1020a is doing outstanding job driving the SG2100 with 1 meter (40'') antenna attached to it. And so many times when I was looking for new sats or adjusting existing ones, I would move the dish left and right and scan for more than an hour, not one problem ever. Same applies to the SkyStar2.