SG2100 woes....update

[wejones]

I haven't posted anything about the problems I've been having with the SG2100, mainly because I got so fed up with it I was about to trash the thing.
I had started re-saving sat positions using my Fortec receiver, thinking that maybe the Twinhan card wasn't able to power the thing. I got a couple sats re-saved, between IA5 and SBS6, however when I went to re-save AMC6, I couldn'teven find it at first, then, I sort of found it, but couldn't peak it to the levels it had previously been.
I was finding that I could "nudge" to the west, but I couldn't nudge back to the east, for some reason. I had become convinced that the plastic gears on the motor had become damaged, and it wasn't allowing me to move to the east. During all this, I had performed multiple goto reference commands, and since AMC6 is just about 1 degree west of my reference zero, I was trying to find the sat by going to reference then nudging west. But I just couldn't peak this sat, even though occasionally I could see a weak signal.

Anyway, to make a long story less long, I at least partially figured out what was wrong today. Today, I first ran the dish west a bit, and did a goto reference command, and went outside to see where it went. It turned out that it went to about 2.5 degrees WEST of ZERO. After trying again to go to AMC6, and not finding it, I decided to test whether the "nudge" command was in fact working. I decided to have my wife hit the "nudge east" command while I was outside watching. She did about 20 nudges, but the motor only moved twice! This confused me, but then I remembered a post I saw here a couple weeks ago, someone who solved their problems by getting rid of the east/west limits. It occurred to me that perhaps my east limit somehow got reset. So I first disabled the limits, then ran the dish way east, and set a limit, then ran it way west, and set another limit.
I then sent the thing back to reference again, but THIS time instead of 2.5 deg west, it went to about 2.5 deg EAST, which is where it was the last time I looked at it (I think that it was EAST of zero by about a degree when I took it out of the box).
After going to reference, I nudged it a few nudges west, and right where I expected it to be I found AMC6, and I was able to peak it. Anyway, what I THINK happened, is that somehow the east limit got reset to about 2.5 deg west of zero, which meant that I couldn't get the dish to move to AMC6, which is only 2 deg west of zero for me.
Anway, I re-saved AMC6, and tried going to SBS6, and I could still got there, sent it to previously saved AMC3, went there, no problems. Ie the thing seems to be working again.

I have NO idea of how the darn EAST limit got changed, I never EVER touched that setting, and I know it was able to move east at one time, because once after repeated nudging, I looked outside, and it had turned about 20 deg east of zero. So somehow there was corrupted data sent to the motor, which reset the limits. Only time will tell, with respect to whether this communications problem will happen again, but at least it seems to be working right now. As mentioned in another thread though, I've also seemed to have problems with my zero reference position getting changed. I'm not sure if perhaps this is related to the above or not. I did do at least one "resync" command, and it may be that after doing a "resync" that the reference zero position in DiseqC 1.2 becomes different from the zero position using USALS.

So while I am still confused about what caused all this, I am at least encouraged that the thing seems to be working again. At least for a while.

[rainman]

these small motors can be aggravating at times. glad to here you got it up and running Bill.

[wejones]

Originally Posted by rainman

these small motors can be aggravating at times. glad to here you got it up and running Bill.

Well this is about the 4th time I thought I was up and running, and each time the motor had a mind of it's own, so I'm keeping my toes crossed.

If nothing else, I can use it as a fixed dish that I can move to another sat with less effort than it would take with an AZ/EL mount. At least I haven't had to change any of the angles on the mount since I installed the thing. My only problems have been getting the motor to come back to where it had been.

When I bought this system, I had 3 goals. My primary goal was to learn about these little motorized systems, and how they compare to big dish systems, but I also wanted to have a second system that would quickly jump to AMC3 PBS (which is where I do most of my satellite viewing), and also wanted a system that I could view one channel while channel surfing with my big dish. So if I can at least get it reliable enough that after moving it to another sat, it would go back to AMC3, I'll be happy.

This latest episode had me worried that the plastic gears had stripped inside the motor. Made me wonder if Sadoun or any other source had repair parts for the motors? I don't think I need them yet, but it would be nice to know where to find them.

[rainman]

that was the reason i went with the stab 100 metal gears.should be a little more durable.

[Sadoun]

Bill

Have you tried to reset the motor using the button on the bottom of the motor? Press the button using a small clip. Keep pressing it, you will see the light flash green/orange a few times, then continues green.

Parts are available if needed.

[wejones]

Originally Posted by Sadoun

Bill

Have you tried to reset the motor using the button on the bottom of the motor? ....

Haven't done the reset thing yet. Actually was in the process of doing that when I discovered that my east limit got changed, so I wanted to play with it a bit more before resetting it. But I'll probably do the reset soon.

Good to know the parts are available. Thanks.

[reho33]

I remember seeing something somewhere kind of like a "mini" actuator for a Ku dish..... I think it was made by eton? Just like the C band one , only smaller for Ku dish. The review even said that it would be more reliable than a H-H motor. Maybe that is the way to go?

[boroda1]

Anyone has a picture how these actuators work?
As I understand, it may be more reliable because of simplicity, but may require an additional investment for "Positioner" device. Also, can anyone tell me, how the LNB (for Ku band) is getting turned/skewed with this setup?
Does need a "mini-polarator"?

[rainman]

Originally Posted by boroda1

Anyone has a picture how these actuators work?
As I understand, it may be more reliable because of simplicity, but may require an additional investment for "Positioner" device. Also, can anyone tell me, how the LNB (for Ku band) is getting turned/skewed with this setup?
Does need a "mini-polarator"?

the c band and ku band polarity is controlled by the same servo motor.the acuators that was mention is a push/pull type acuator called linear.

[boroda1]

Thanks, Rainman!
So, if I want an actuator to move my dish, I need a positioner (to control this actuator), and a servo motor to turn LNB, and possibly, an LNB of specific shape to work with a servo motor?

[wejones]

Originally Posted by boroda1

Thanks, Rainman!
So, if I want an actuator to move my dish, I need a positioner (to control this actuator), and a servo motor to turn LNB, and possibly, an LNB of specific shape to work with a servo motor?

Most of the newer big dish receivers have built in positioners, which will control most any actuator or big H-H. The servo motor doesn't turn the LNB, and doesn't attach to the LNB. Most big dish systems use separate feedhorns. The LNBs bolt into the feedhorn, and the servo motor also attaches to the feedhorn, and turns little probes that control the polarity of the signal going up the wave guides to the lnbs. Virtually ANY LNB is compatable with the feed-horns.

[boroda1]

Thanks for the info!
I am not familiar with big dish, cannot imagine how all this works.
Probably, you mean that ANY LNB, but not LNBf is compatible with feedhorns?
I am just doing google image search for "feedhorns" and don't get it, how LNBf such as FSKUv or whatever will firt in those.

[wejones]

Originally Posted by boroda1

Thanks for the info!
I am not familiar with big dish, cannot imagine how all this works.
Probably, you mean that ANY LNB, but not LNBf is compatible with feedhorns?

the "f" in LNBF is the feedhorn. Ie LNBFs include the feedhorn, and no, you can't connect an LNBF to a feedhorn

Originally Posted by boroda1

I am just doing google image search for "feedhorns" and don't get it, how LNBf such as FSKUv or whatever will firt in those.

Look at
http://www.skyvision.com/store/mi3503007.html

this shows the most popular feedhorn. The little rectangular blue box at the left is the polarotor. There are no lnbs installed in this picture. The C band LNB attaches at the big flat plate at the bottom, and the Ku attaches at the small plate at the top.
These feedhorns are not cheap, and neither are the LNBs you use with them, but you have a much wider variety of quality of LNBs. You can pay anywhere from $50 to $1000 for an LNB. Most people think Norsat lnbs are the best. CalAmp are OK Eagle Aspen are less than OK. (Actually OK as long as they work, but mine only lasted 3 weeks.)

There are also so called Ortho mode feedhorns (I think that's the term), that don't have a polarotor, but instead have separate H and V LNBs. These are supposed to be better, but obviously are more complicated to wire, as you need coax for each, and you need switches to switch between them and are more expensive due to double the # lnbs.

[elgemcdlf]

Originally Posted by boroda1

Thanks for the info!
I am not familiar with big dish, cannot imagine how all this works.
Probably, you mean that ANY LNB, but not LNBf is compatible with feedhorns?
I am just doing google image search for "feedhorns" and don't get it, how LNBf such as FSKUv or whatever will firt in those.

Had to laugh a bit to myself on this one. I am the exact opposite Big dish is no big deal and it is the little ones that drive me crazy.

[rainman]

it's just what ever you get use to.