Motor Problems

[Jim-S]

A couple guy's have been trying to help me, from this forum....with my problem....
Mercury II, DG240,90cm dish.....when I first installed it (July '07) it worked fine for about 2 months. Now I am having a problem getting the dish to move, it seems to move when it wants to. I tried to reset the motor,...... I disconnected the coax for awhile,.... I moved the receiver to the motor and it still acts the same. I did see at times that when I would hit the "OK" button to move the dish, it wouldn't move right away, after about 5 to 8 seconds it would move. But most of the time it wouldn't move at all. To me it (seems) like a motor or receive problem....but this is my first time at FTA, I'm hoping some of you seasoned sat-guys can help.
My next move would be to call "Sadoun" for help.
Thank-you

[Jim-S]

I'm still having problems, I have replaced all the coax with Belden copper core 60% braid and the problem persists. Now I'm starting to wonder how can I test or determine if it is the DG240 or the Mercury II. To review, the motor will move maybe to three or four sats then it will not move again, the next day it may move to a sat and then it will not move again. I can not find a pattern to the problem it may move or it may not. I did a factory reset on the receiver, no help. There is nothing in the way of the dish to prevent movement.
I have the mast grounded with an 8' ground rod with #6 copper wire. Then grounded to the main electrical ground in the house. FYI.
The dish sits on a 7'x2" mast.
Help........................!
I'm using USALS, I have no problem when it does move hitting the right sat.

[ayelvington]

Jim,
I read your thread and will drop a few suggestions:

1. Have you had someone out at the dish looking at the status lights while someone inside is commanding the dish to move? The power lamp should be lit and you should see the East/West light flash with the command. The details are in the manual.
2. How long is your cable run? If the run is too long you could be introducing a problem related to voltage drop. Not likely since you say the system worked for a while, but worth considering.
3. Please describe trying to move the dish with manual commands (not USALS) and what you see at the dish (lights, movement, etc).
4. Weather. I hate this one, but it's been getting colder in the heartland, and you may have a temperature sensitive part in the motor that's failing. I had a H-H motor with that problem that I ended up throwing out.

I've never done a return to Sadoun, but you could be the guinea-pig for the rest of us on how well they handle warranty issues.

I hope you can fix this before it gets really cold; I imagine you're already working on it in the dark!

Al

[Jim-S]

Originally Posted by ayelvington

Jim,
I read your thread and will drop a few suggestions:

1. Have you had someone out at the dish looking at the status lights while someone inside is commanding the dish to move? The power lamp should be lit and you should see the East/West light flash with the command. The details are in the manual.
2. How long is your cable run? If the run is too long you could be introducing a problem related to voltage drop. Not likely since you say the system worked for a while, but worth considering.
3. Please describe trying to move the dish with manual commands (not USALS) and what you see at the dish (lights, movement, etc).
4. Weather. I hate this one, but it's been getting colder in the heartland, and you may have a temperature sensitive part in the motor that's failing. I had a H-H motor with that problem that I ended up throwing out.

I've never done a return to Sadoun, but you could be the guinea-pig for the rest of us on how well they handle warranty issues.

I hope you can fix this before it gets really cold; I imagine you're already working on it in the dark!

Al

Q-1 I have not had anyone at the dish. Maybe I can get my "wife" to help.
Q-2 My cable run is 120', tried it with 30' of coax and it failed. Moves once in ahwile. I tried a 10' piece it seemed fine but maybe I should have tried longer.
Q-3 I can move the motor or dish by the buttons on the motor east and west with no trouble. The lights do flash properly at an idle.
Q-4 I had this trouble in hot weather or cold. I have read about this also.
I think these DG240 are fairly new and maybe not enough out there for a good test.
Thanks for the reply...........

[Jim-S]

As some of you know I have been having trouble moving my dish, satellite positions are correct. Picture quality is great.....I've replaced all my coax with Belden 1829AC satellite rated. I have talked to Steve (Tech) at Sadoun, told him my problem he is going to some research and we will get back together. Since I talked to him I decided to keep a log of the trouble. What I found out is if I disconnect the coax from the receiver for sometime and reconnect it I can move the dish. I did this 3 times. First time I move it 5 times, second time I moved it 17 times, the third time I moved it 14 times before the problem came back. Then it stuck on the last sat. and couldn't move it. I could unplug the coax (I have been doing it over night or 24 hrs) and start all over again???????????
Jim

[ayelvington]

In my twisted mind I'm thinking you have a bad ground somewhere. You might check the outlet that you have your receiver plugged into. Neutral and Ground are supposed to be tied at the panel. If you don't have a good ground there, then your coax could be providing the ground and causing some bias voltage build-up. This is a moon-shot of a theory, but I've seen bad grounds reek havoc on systems built with quality equipment.

[wejones]

Originally Posted by ayelvington

In my twisted mind I'm thinking you have a bad ground somewhere. You might check the outlet that you have your receiver plugged into. Neutral and Ground are supposed to be tied at the panel. If you don't have a good ground there, then your coax could be providing the ground and causing some bias voltage build-up. This is a moon-shot of a theory, but I've seen bad grounds reek havoc on systems built with quality equipment.

I wouldn't be at all surprised. I've seen some weird ground problems over the years too. One time I had about 50V AC between the grounds on two different devices I was connecting by cables.... not a good thing.

If this does turn out to be a ground problem, I'd be really interested in if/how this dish is grounded. Many people have a tendency to try to ground the dish at the dish, but even though many people don't agree with me, I feel that this can often cause more problems than it solves, because it's pretty difficult for the average homeowner to provide a proper ground at the dish. You really should only have one ground. The main requirement is to ground the coax where it comes into the house, at the service ground, but this is often not done, because often the service ground is on the opposite side of the house from where the dish is. Many people end up in the quandry of knowing they aren't going to follow code, and have to decide between not grounding at all, or trying to provide an unsatisfactory ground at the dish. I'm under the opinion that in this situation, you're better off not grounding the dish.

Anyway, I'll be interested in what ends up being the cause of this.

[MrBillM]

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[Jim-S]

Thanks for the reply...I did what you suggested, I had the dish grounded with an 8' grd rod with #6 copper wire with it also grounded to the service ground. I disconnected the grounds, it worked for awhile then back to the same problem. It moves sometimes. This morning (with new snow on the ground ha ha ) I did more testing, I used a 50' piece of coax had the same problem. Then I used another 50' piece same trouble. I tried a 30' piece and it (moving the motor) worked fine. Went back to the 50' coax and it failed. I think I have a Mercury II problem. Not enought power. Any thoughts you might have would be welcome. Jim-S

Originally Posted by wejones

I wouldn't be at all surprised. I've seen some weird ground problems over the years too. One time I had about 50V AC between the grounds on two different devices I was connecting by cables.... not a good thing.

If this does turn out to be a ground problem, I'd be really interested in if/how this dish is grounded. Many people have a tendency to try to ground the dish at the dish, but even though many people don't agree with me, I feel that this can often cause more problems than it solves, because it's pretty difficult for the average homeowner to provide a proper ground at the dish. You really should only have one ground. The main requirement is to ground the coax where it comes into the house, at the service ground, but this is often not done, because often the service ground is on the opposite side of the house from where the dish is. Many people end up in the quandry of knowing they aren't going to follow code, and have to decide between not grounding at all, or trying to provide an unsatisfactory ground at the dish. I'm under the opinion that in this situation, you're better off not grounding the dish.

Anyway, I'll be interested in what ends up being the cause of this.

[Jim-S]

See quote above to wejones...........................

[Jim-S]

I have done more testing...I still have the problem of moving the dish...Thanksgiving morning I set everything up in my garage. First I tried 50' of coax then another they failed just as the 120' of coax did. I used a 30' of coax it worked fine as well as 10' of coax. Went back to 50' of coax it fails. I still get a good signal and picture on the satellite it is stuck on. At times it may move to another satellite and get stuck there. Saturday I measured the voltage on several different coax lenghts including 120' to the dish I get 13+ volts and 18+ volts depending on if the channel is vertical or horizonal. I assume that the motor moves on a digital command from the receiver, I did not see any voltage change when trying to move the dish.
I don't think I have a coax problem I am now using Belden 1829AC satellite copper core 60% braid......I may have to send motor and or receiver to be tested. The system acts the same if it is completely grounded or not. Any suggestion would be greatly welcome.
Jim

[wejones]

Originally Posted by Jim-S

I have done more testing...I still have the problem of moving the dish...Thanksgiving morning I set everything up in my garage. First I tried 50' of coax then another they failed just as the 120' of coax did. I used a 30' of coax it worked fine as well as 10' of coax. Went back to 50' of coax it fails. I still get a good signal and picture on the satellite it is stuck on. At times it may move to another satellite and get stuck there. Saturday I measured the voltage on several different coax lenghts including 120' to the dish I get 13+ volts and 18+ volts depending on if the channel is vertical or horizonal. I assume that the motor moves on a digital command from the receiver, I did not see any voltage change when trying to move the dish.
I don't think I have a coax problem I am now using Belden 1829AC satellite copper core 60% braid......I may have to send motor and or receiver to be tested. The system acts the same if it is completely grounded or not. Any suggestion would be greatly welcome.
Jim

Re: "I assume that the motor moves on a digital command from the receiver, I did not see any voltage change when trying to move the dish."

Sort of. The motor commands are sent over a 22khz signal that is modulated with the digital info. You wouldn't see any voltage change when it was sending the diseqc commands, but I'd expect you to see a voltage change when it actually tried to move. (I'm assuming that you're reading voltage off a "T", so that the motor and lnbf are still being powered, otherwise the voltage readings aren't so meaningful.) So it would seem like the motor just isn't receiving the command to move for some reason.

Since the signal is sent over 22khz, if you have a universal lnbf, which uses 22khz for it's high LO freq, and/or a 22khz switch, and/or a diseqc switch, which also uses 22khz, I guess there is a possibility that there is some interaction between the various 22khz signals, although in theory they should be able to co-exist. But if you by chance have 22khz turned on, or are using a switch, you might experiment by turning the 22khz off before sending the move commands. But this shouldn't really be a factor.

If you had one of those Channel Master style meters (Sadoun used to sell a version, but I don't see one listed now.) it will show you when the 22khz signals are being sent. My meter has a little light that blinks whenever it sees 22khz, and it would blinks when it sees a diseqC command being sent.
However it won't tell you the magnitude of the 22khz. If you have an oscilloscope, you can see the 22khz signals, and you might be able to see if there is a difference in magnitude with the different cable lengths. But without an oscilloscope, not sure how you would do that.

Anyway, your problem is really strange. It does seem that you're having a problem getting the 22khz signals down the coax. Either the motor is a bit insensitve receiving the signal, or the receiver isn't putting out sufficient signal level, or somehow the signal is getting lost in the coax..... or perhaps for some reason there is a lot of noise in the system, that's confusing the signals??? I know that Sadoun says there is a coax length issue, but I'm running well over 200', and don't have this problem, either with motor or diseqC switch.

This is where it comes in handy to have another receiver to test with.

[Jim-S]

Thank you very much for your reply....

Originally Posted by wejones

Re: "I assume that the motor moves on a digital command from the receiver, I did not see any voltage change when trying to move the dish."

Sort of. The motor commands are sent over a 22khz signal that is modulated with the digital info. You wouldn't see any voltage change when it was sending the diseqc commands, but I'd expect you to see a voltage change when it actually tried to move. (I'm assuming that you're reading voltage off a "T", so that the motor and lnbf are still being powered, otherwise the voltage readings aren't so meaningful.) So it would seem like the motor just isn't receiving the command to move for some reason.

Since the signal is sent over 22khz, if you have a universal lnbf, which uses 22khz for it's high LO freq, and/or a 22khz switch, and/or a diseqc switch, which also uses 22khz, I guess there is a possibility that there is some interaction between the various 22khz signals, although in theory they should be able to co-exist. But if you by chance have 22khz turned on, or are using a switch, you might experiment by turning the 22khz off before sending the move commands. But this shouldn't really be a factor.

If you had one of those Channel Master style meters (Sadoun used to sell a version, but I don't see one listed now.) it will show you when the 22khz signals are being sent. My meter has a little light that blinks whenever it sees 22khz, and it would blinks when it sees a diseqC command being sent.
However it won't tell you the magnitude of the 22khz. If you have an oscilloscope, you can see the 22khz signals, and you might be able to see if there is a difference in magnitude with the different cable lengths. But without an oscilloscope, not sure how you would do that.

Anyway, your problem is really strange. It does seem that you're having a problem getting the 22khz signals down the coax. Either the motor is a bit insensitve receiving the signal, or the receiver isn't putting out sufficient signal level, or somehow the signal is getting lost in the coax..... or perhaps for some reason there is a lot of noise in the system, that's confusing the signals??? I know that Sadoun says there is a coax length issue, but I'm running well over 200', and don't have this problem, either with motor or diseqC switch.

This is where it comes in handy to have another receiver to test with.

[ayelvington]

I'm beginning to suspect your motor. My rational is that the impedance of the cable to 22kHz is pretty nil. On the other hand, a single component failure in the motor could be deafening it to the signal.

If you don't have access to another receiver to do a comparison with, I recommend the STAB MP01 (or MP02) as a cheap substitute. It generates the same DISEQC signals as the receiver but costs less. I can't find mine at the moment, or I'd offer to lend it to you.

a

[Jim-S]

Thanks for your reply I am using usals, I don't think that would matter. My units are still under warranty. I may have to send them to Sadoun or a factory tech, to check them out. I hate to remove my motor, it was so hard for me to get setup ha ha.

Originally Posted by ayelvington

I'm beginning to suspect your motor. My rational is that the impedance of the cable to 22kHz is pretty nil. On the other hand, a single component failure in the motor could be deafening it to the signal.

If you don't have access to another receiver to do a comparison with, I recommend the STAB MP01 (or MP02) as a cheap substitute. It generates the same DISEQC signals as the receiver but costs less. I can't find mine at the moment, or I'd offer to lend it to you.

a

[ayelvington]

Be sure to put a mark on the post for true South, and maybe eye-ball a distant marker to give you a good line-of-position. A fast way would be to command the dish to return to the reference point (0), hang string from the two ends of the LNBF holder, and sight down them to what they are aligned on. you could even put a stake in the ground or something. just a thought.

Good luck!