Hi all: I'm trying to set up my BUD and am new here so please bear with me. I'm really confused about the wires that come from my Chaparral Corotor II Plus. There is one red, one black, and one white wire which I assume control the polarity of the signal at the feedhorn. I am using a digital Coolsat 5000 receiver to view the video and an old analog Uniden UST-4500 receiver to control the dish. So if I have this setup, does this mean that if I want to watch the channels from a specific satellite, I have to turn the dish using the Uniden, and also adjust the skew and polarity with the Uniden (since the Uniden has inputs in the back for these three wires), and then use the Coolsat as a passive receiver? So, what does the Coolsat do? Isn't it capable of adjusting the skew and polarity? What if I didn't have the Uniden receiver? Where would the three wires from the Corotor connecto to? I don't get it. I'm sure I'm missing something important here.
Confused - Uniden UST-4500 and Coolsat 5000
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on the right track
That's exactly the way I use my big dish for c=band digital, the analog receiver/descrambler (a General Instruments 650I ) moves the dish and controls the polarity. Only thing to remember is, if you blind-scan with the fta receiver, you have to watch for the point where it switches polarity during the blindscan, and switch your analog box from an odd to even #channel so the polarity motor will switch. No big deal, since most of my digital watching is on ku band anyway.
I think there are a few fta receivers that can control a polarotor, and nowadays there are motor-less C-band feedhorns, that electronically switch polarity for you..one of those would be sweet for watching digital channels!
All the fta rec does is find and store your digital channels, in your scenario and mine.
That's exactly the way I use my big dish for c=band digital, the analog receiver/descrambler (a General Instruments 650I ) moves the dish and controls the polarity. Only thing to remember is, if you blind-scan with the fta receiver, you have to watch for the point where it switches polarity during the blindscan, and switch your analog box from an odd to even #channel so the polarity motor will switch. No big deal, since most of my digital watching is on ku band anyway.
I think there are a few fta receivers that can control a polarotor, and nowadays there are motor-less C-band feedhorns, that electronically switch polarity for you..one of those would be sweet for watching digital channels!
All the fta rec does is find and store your digital channels, in your scenario and mine.
If you didn't have the Uniden you would have to come up with another method of moving your dish, that could be accomplished with a V-Box or G-box in tandem with your Coolsat...but you would still not be able to control the polarity of your CoRotor.
A voltage-controlled LNBF would eliminate the need for CoRotor-type polarity control, but that's a whole 'nother chapter and verse there, some people have had issues with that type of feed (having to compromise between the peaking oftheir C....or their Ku band signals).
As turbosat mentioned there are some DVB receivers that will control polarity, but the Coolsat is not one of them.
One of the sponsors (Sadoun) is working with his suppliers to develop a new version of the G-Box that will control polarity on a servo-style feedhorn, as well as control dish movement of a BUD (in conjunction with a DVB receiver, Coolsat 5K in your case).
If you had a V or G-Box to control your BUD movement....and if you had a way to control polarity, at that point the only thing the Uniden does for you is allow you to get the analog signals that remain in the clear.
I still use my analog box for that, as well as polarity control and dish movement, works great for me.
A voltage-controlled LNBF would eliminate the need for CoRotor-type polarity control, but that's a whole 'nother chapter and verse there, some people have had issues with that type of feed (having to compromise between the peaking oftheir C....or their Ku band signals).
As turbosat mentioned there are some DVB receivers that will control polarity, but the Coolsat is not one of them.
One of the sponsors (Sadoun) is working with his suppliers to develop a new version of the G-Box that will control polarity on a servo-style feedhorn, as well as control dish movement of a BUD (in conjunction with a DVB receiver, Coolsat 5K in your case).
If you had a V or G-Box to control your BUD movement....and if you had a way to control polarity, at that point the only thing the Uniden does for you is allow you to get the analog signals that remain in the clear.
I still use my analog box for that, as well as polarity control and dish movement, works great for me.
Thanks Turbosat and Phlatwound for the responses. I think I understand now. Turbosat states that "No big deal, since most of my digital watching is on ku band anyway". Why isn't it a big deal with Ku band? Does that imply that Ku does not require polarity changes but C-band does? I'm beginning to think that the used Corotor I purchased is broken since the signal (what I see on the TV monitor) doesn't seem to change when I change polarity using the Uniden. I have the polarity wires connected to the Corotor and I can see that when I press the polarity button on the Uniden remote, the voltage on the outputs (I think pulse and ground) goes from 0.3 volts to 6 volts. So something happens electrically but I don't see any change in the picture. I guess my next step is to take the Corotor down off the dish and see if the little motor turns. If it doesn't turn, then I asume that something is broken (either the Uniden or the corotor motor). Then I have to find out which one.
I believe what turbo is saying is that he has a seperate dish for Ku reception, and that dish has a voltage-controlled LNBF on it.
That means, when he does Ku a blindscan the polarity is switched automatically by the fta reciever (Coolsat 5K in your case)....but when he does a C-band blindscan he just watches what tps are being scanned and switches the polarity of his Corotor manually with his analog box, depending on whether or not he wants H or V.
If your Coolsat doesn't allow you to see the tp polarities as you scan you can just do a blindscan with your Corotor set to H....than repeat the process with it set to V.
Great, I'm understanding more by the minute. So, assuming that the Uniden and the Corotor are both working correctly, I have to make sure that my Uniden is set to the proper polarity for each channel when the blindscan is done (a complete blind scan on H and then a complete blind scan on V). But as I asked in my previous message, doesn't that also mean that if I'm watching on the video monitor a channel that has horizontal polarity... if I then switch the polarity from horizontal to vertical on the Uniden, the video should go bad? My video signal doesn't seem to change and that's the part I'm trying to understand. Can you help? I'm trying to diagnose if there is a problem with the Corotor ASAP. If there is a problem with it, I want to be able to send it back to the store that sold it to me before the 30-day warranty is up and I only have about 1 week left.
Yes, if you are watching a horizontal channel and when you select a vertical channel your picture doesn't change you have an issue.
What happens when you select a different horizontal channel? Are you watching C-band or Ku-band, digital or analog when you do this?
Can you get your ear fairly close to your servo and have someone at the receiver go from H to V? It sure sounds like the probe is not moving but I'm not sure why.
I'll keep asking you some (dumb?) questions and eventually you'll give enough info that someone will be able to diagnose for you.
I removed the Corotor from the dish, brought it into the house, and connected DIRECTLY to the back of the Uniden analog tuner. The little antenna-like thing inside the Corotor rotates! It makes a distinct and clear whirring noise that I didn't hear when it was mounted on the dish, so I assume that there was a bad connection or a broken wire in the cable I was using to test it. Based on how I have the skew set on the Uniden, the amount of rotation of the Corotor arm will be up to 180 degrees. However, I would guess that to set it properly, changing from vertical to horizontal polarity on the Uniden should make the little antenna rotate by 90 degrees (correct?). I'm going to re-mount the Corotor on the dish as described below. Please tell me if I'm correct.
1) While still in the house, set the Uniden to Vertical polarity so that the Corotor is set to Vertical
2) Take the Corotor to the dish and mount it with a rotation such that reception of a signal broadcast with Vertical polarity is maximized.
3) I should NEVER need to use the skew adjustment since all signals will be either vertical or horizontal, and they are the same whether they are C or Ku. Am I correct in this last statement?
1) While still in the house, set the Uniden to Vertical polarity so that the Corotor is set to Vertical
2) Take the Corotor to the dish and mount it with a rotation such that reception of a signal broadcast with Vertical polarity is maximized.
3) I should NEVER need to use the skew adjustment since all signals will be either vertical or horizontal, and they are the same whether they are C or Ku. Am I correct in this last statement?
Yes it should rotate 90 degreees when changing from horizontal to vertical. The only sat that will need the skew to be adjusted differently is AMC4 Ku at 101 degrees. The Ku band on that sat does not follow the standard. The corotor will need to move the probe when switching from hor to ver, so you will need to correct the wiring problem.
OK, I got the Corotor installed and had my wife read the signal strength numbers on the TV out loud while I adjusted the feedhorn (rotation and in/out) to maximum value. I could get up to about 95% signal strength. Once the Corotor was adjusted properly, I tuned in a vertically polarized channel (identified as vertical using an online list from Lyngsat) with the Coolsat 5000. As expected, I got a nice clear signal if the LNB was set to vertical polarization, and no signal if the LNB was set to horozontal polarization.
However, there is one thing that doesn't make sense to me. Some of the channels on the same satellite do not seem to respond to a change in the LNB polarity. I can change form vertical to horizontal polarity on the feedhorn and the signal strength and resulting image on the screen for those channels don't change at all. I know that the Uniden is actually changing the polarity because I can hear it rotate and it works for other channels. I tried it over and over with the same set of channels and some of them don't seem to care whether the polarity is vertical or horizontal. Can anyone explain why this is happening?
However, there is one thing that doesn't make sense to me. Some of the channels on the same satellite do not seem to respond to a change in the LNB polarity. I can change form vertical to horizontal polarity on the feedhorn and the signal strength and resulting image on the screen for those channels don't change at all. I know that the Uniden is actually changing the polarity because I can hear it rotate and it works for other channels. I tried it over and over with the same set of channels and some of them don't seem to care whether the polarity is vertical or horizontal. Can anyone explain why this is happening?
Are you visually verifying that it is turning every time? If so, that doesn't make sense to me, may be an easy answer that someone here will know though.
Well, not visually because the feedhorn is adjusted, I don't want to move it again, and it is mounted way up there pointing at the satellite. But, I do hear it turn every time for all channels. There were about 3 or 4 channels that polarity didn't work on but another 5 or 6 where it did. I could switch between these two types of channels and change the polarity again and again and the channels where it would work would work all the time (and I could hear the feedhorn turn), and where it wouldn't make a difference, it wouldn't make a difference every time (and I could hear the feedhorn turn). I don't understand how that happens.
Are the ones that do not change all one polarity and the ones that do the other? I remember something like that for some receiver "we" had back in 1986... The polarity button only switched to horizontal as I remember - could have been the other way, but if it works without using the button, then --- it works!
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