H/V Polarity Issue not consistent

[pebo666]

I am new to this forum so please bear with me. I have been in FTA for 1.5 years now and have had great success. However, with one of my BUD's I have a polarity issue. For example: on AMC4 I can not get any Vertical polarity TP's. But on another sat I can get V & H. I thought it was the little blue box that needed changed but why would it work on same sats and not others? I have read where if you can't get either H/V to change the servo motor. I didn't think this was the issue because it works on some but not others. Any help would be appreciated.


Brook
7.5 mesh, 10' Sami mesh, Vbox 710, Fortec Ultra,ZS100 Analog, 90cm, P*, 8' offset solid (old) all free except receiver and little dish. My wife says NO MORE!

 

[JohnH]

You might check your cables to make sure you don't have a intermittent which is affected by the way the dish is pointed.

 

[voomvoom]

I had a simular problem several years back. I had changed the servo motor and some sats worked fine, while others only did one side of the polarity. Come to find out, I had installed the servo incorrectly. The thing will only turn 360 degrees in either direction, so you need to get it in the middle, or close. I had to take it back off and while looking at it, using the remote, I changed the channel on the receiver. It did not move, so I changed sats and it moved. Then, I figured if I turned it with my finger 180 degrees it would still work. So, I went back to the sat that didn't work and it was working. Don't know if you have the same problem, but it won't hurt to give it a try. Hope this can help you.

Al

 

[pebo666]

Thanks for the reply. I have checked all cables and temporarily ran new ones and that is now ruled out. I will take it apart (remove it, not actually take it apart) I guess and make sure it is turning or not. You gave me something to think about and test. Thanks.

I also used my Fortec on my bigger dish today and it is doing the same thing. Only on this bigger (10') dish I get different TP's, not the same ones. However, some are the same. I am wondering if it's not the Fortec.

 

[BudMe]

The following is from the Chaparral support site, hope it helps:

How to recognize a polarity problem
Polarity problems are usually very easy to recognize. They are usually indicated by the fact that every other channel is bad. You will notice that on some satellites, only the even numbered channels will come in, while on other satellites only the odd numbered channels will come in. This happens because the probe inside the feedhorn will not turn the 90 degrees that is required to change from a horizontally polarized channel to a vertically polarized channel. If your satellite system is several years old, the problem is most likely that the servo motor that drives the probe has failed. Here are some steps to take to find the problem:

1. Use a volt meter to check the voltage at the back of your receiver to make sure that the voltage is coming out of your receiver. The connector to check is usually labeled "Polarizer +5v" or Polarity +5v". Disconnect the wires that go to the dish and measure the +5 connector to GND. You should have approximately +5 to +6.5 volts dc. Chaparral receivers put out a constant +5 supply, so the voltage should be there as long as the receiver is turned ON. Other brands of receiver may only put out the +5 when the channel is being changed or when the polarity/skew is being adjusted.
2. Check for dc voltage at the pulse connector. The pulse output is what tells the servo motor how far to turn the probe. You will read from .2 to .9 (+)volts dc here. In most receivers, this voltage will only be present when the channel is being changed or when the polarity/skew is being adjusted.
3. If the receiver is putting out the proper voltages on the pulse and +5v connectors, re-connect the wires that go to the dish. Then, go out to the dish and remove the feedhorn cover. Disconnect the 3 wires that are connected to the servo motor. Measure to verify that you are getting the pulse and +5 voltage on each respective wire. If you are NOT getting the same voltage as you had at the receiver, then you have a wiring problem. If you are getting the same voltage, reconnect the 3 wires, proceed to step 4.
4. Have someone inside change channels on the satellite receiver. If you hear the servo motor turning, but there is no apparent change in the position of the probe (remove the throat cover and look inside the throat to see the probe), remove the servo motor and pull up gently on the amber colored drive shaft that couples to the servo motor. If the shaft pulls out, you will need to send the entire feed to Chaparral for repair.
5. If the servo motor does not turn, and you have the correct voltages getting to the motor, that normally indicates that the motor is bad and needs to be replaced. You can usually purchase a servo motor at any satellite dealer.

If you find that the servo motor seems to be buzzing all of the time or if you are watching a program that seems to fade out intermittently and will come back by itself or if you change the channel up or down and back, the problem is also likely to be a bad servo motor. But try these steps to determine if the problem is more serious:

1. Take the servo motor off of the feedhorn and hook it up directly to the back of your receiver. You must disconnect the wires going to the dish for this test to be valid.
2. Watch the servo while you change channels, then let it sit for a couple of minutes. If it turns when you change channels and does not drift or buzz when you are not changing channels, that tells you that the receiver and servo motor are working properly and the problem is likely to be noise being pick up by your unshielded pulse line. The only way to correct this problem is to make sure that the pulse line is shielded and the shield is grounded at one end.
3. If the servo motor behaves the same way when it is hooked up directly behind the receiver as it did out at the dish, then it is most likely bad. You need to replace it.

 

[WyrTwister]

Thanks for the reply. I have checked all cables and temporarily ran new ones and that is now ruled out. I will take it apart (remove it, not actually take it apart) I guess and make sure it is turning or not. You gave me something to think about and test. Thanks.
I also used my Fortec on my bigger dish today and it is doing the same thing. Only on this bigger (10') dish I get different TP's, not the same ones. However, some are the same. I am wondering if it's not the Fortec.

I did not realize any Fortecs have the connections for the Polorotor ? My Ultra does not . Pansat does . I use an analog receiver to change polarity .

I was told to set the Polorotor at 10:30 position & the LNB at 04:30 . ( if you have a feedhorn with both C & Ku , it may be different ) .

The Polorotor only has to rotate 45 degrees from " center " to the east or to the west , to get 90 degrees of seperation from H to V .

Also , some sats use " normal " polarity , some use " reverse " polarity . This means some sats have the odd channels V , some have the odd channels H . This seems to help prevent " bleed over " from sats to the east and to the west .

Wyr

 

[pebo666]

The Ultra doesn't as you stated. I think maybe there was some misunderstanding of the posts. I have my analog receiver connected to the Ultra on the loop connection with a DC block on it. The IF/SAT in on the Ultra is the main line coming in from the dish. The analog reciever receives analog signals and moves the dish. I have nothing connected to the polarizer on the analog receiver. Which means the Ultra is changing the polarity. I found the setup on another forum and they said that it would work so I tried it. And everything works fine. The polarity issue I have was before this setup and it is the same now with this setup also. I have some adjusting of the LNB to the 4:30 position, it is off a little not much maybe this will correct the problem.

 

[WyrTwister]

The Ultra doesn't as you stated. I think maybe there was some misunderstanding of the posts. I have my analog receiver connected to the Ultra on the loop connection with a DC block on it. The IF/SAT in on the Ultra is the main line coming in from the dish. The analog reciever receives analog signals and moves the dish. I have nothing connected to the polarizer on the analog receiver. Which means the Ultra is changing the polarity. I found the setup on another forum and they said that it would work so I tried it. And everything works fine. The polarity issue I have was before this setup and it is the same now with this setup also. I have some adjusting of the LNB to the 4:30 position, it is off a little not much maybe this will correct the problem.

Let me get this straight . Coax from dish goes to the Ultra . From the Ultra , it goes to the analog receiver ?

This is how I have mine set up .

But , I have the red , black and white wires from the polorotor connected to the analog receiver , to control polarity .

I am running a mini bud ( 90 cm offset dish ) & Stab HH100 motor . The Ultra controls the motor .

I use the Ultra to move the dish & power the LNB .

Then turn on the analog receiver . The analog receiver changes polarity when I change channels on the analog receiver .

Did I ask if you are running a LNB or a LNBF ?

Latter,
Wyr

 

[ken2400]

What do you have for an LNB and how old?

I am new to this forum so please bear with me. I have been in FTA for 1.5 years now and have had great success. However, with one of my BUD's I have a polarity issue. For example: on AMC4 I can not get any Vertical polarity TP's. But on another sat I can get V & H. I thought it was the little blue box that needed changed but why would it work on same sats and not others? I have read where if you can't get either H/V to change the servo motor. I didn't think this was the issue because it works on some but not others. Any help would be appreciated.
Brook
7.5 mesh, 10' Sami mesh, Vbox 710, Fortec Ultra,ZS100 Analog, 90cm, P*, 8' offset solid (old) all free except receiver and little dish. My wife says NO MORE!

 

[pebo666]

Let me get this straight . Coax from dish goes to the Ultra . From the Ultra , it goes to the analog receiver ?
This is how I have mine set up .
But , I have the red , black and white wires from the polorotor connected to the analog receiver , to control polarity .
I am running a mini bud ( 90 cm offset dish ) & Stab HH100 motor . The Ultra controls the motor .
I use the Ultra to move the dish & power the LNB .
Then turn on the analog receiver . The analog receiver changes polarity when I change channels on the analog receiver .
Did I ask if you are running a LNB or a LNBF ?
Latter,
Wyr

That is correct. My Ultra controls the mini bud and the analog reciver controls the bud. The only difference is that I don't have the red, black or white wires connected to the analog reciever. It works just fine without them. I use the analog receiver to move the bud for the Ultra because as we know the Ultra cannot move a bud. I have a DP710 but it drifts and it isn't reliable. I use an LNBF and it is several years old. I got all of my dishes used so I am not sure of their age. I use the Ultra to power all of my LNB's.

 

[pebo666]

What do you have for an LNB and how old?

Not sure of the exact make. I took off the feedhorn cover and have a Gardiner .25 degree LNB. Nothing else is marked. All of the dishes I got used so I am not sure of the age of the equipment.

 

[ken2400]

Seems new enough. I would try to get a new 15 or lower LNB that switchs via voltage instead of servo.

Good luck

Not sure of the exact make. I took off the feedhorn cover and have a Gardiner .25 degree LNB. Nothing else is marked. All of the dishes I got used so I am not sure of the age of the equipment.

 

[pebo666]

I found the problem. I turned the LNB to about 4:30. It was on about 5:30. It was off enough that I wasn't getting both H/V. I do now and I hooked up the analog reciever wires in the back and all is well.