NBC DVB-S2 Feeds on AMC1 Ku

[TreyWingbat]

I guess I should adjust the few other LNB's I have on the rail that are offset for proper skew. Again, I never really thought about skew before, because of the motorized system. I started out with the center LNB of course, but now have added a few other LNB types to the rail.

So the skew of the LNB at the center should be 0 whenever the motor is at zero (assuming I put the LNB on straight at this point), correct? That means that whatever angle difference between no skew at the center of the motor and the skew degrees at H2 is, I should apply that at 103? This way I'm taking the 0 point of the motor, instead of setting things up at 110? I'm not near the dish right now, but if my 0 point of the motor is at 82 degrees, then the difference between 82 and 74 (H2) shouldn't be much of a skew, should it?

 

[Scott Greczkowski]

If I remember correctly the skew is off on the 103 satellite, so what you are seeing is normal.

 

[TreyWingbat]

Yes, a 25 degree skew for 103 from where it should normally be skewed, but since I don't have 103 setup for it's proper skew (as I've never setup for skew before), to match the skew on 74 (H2), I should just read the skew from the 0 point, and rotate 103 that much from 0. The skew for 103 should normally be CCW a certain degrees (if looking at the dish head-on), and the skew for 74 CW (based on where I am), but I'll just forgoe the original skew setup for 103 (so I won't have any CCW rotation to begin with), and will just skew a bit CW from 0 for 103 to get NBC.

So for example, if originally 103 should be skewed 18 CCW, but for NBC it needs to be rotated 25 degrees CW to match 74 (H2), I should just go 7 degrees CW from 0 degrees (straight alignment for the LNB). This should work I think.

 

[Keith Brannen]

Yes, a 25 degree skew for 103 from where it should normally be skewed, but since I don't have 103 setup for it's proper skew (as I've never setup for skew before), to match the skew on 74 (H2), I should just read the skew from the 0 point, and rotate 103 that much from 0. The skew for 103 should normally be CCW a certain degrees (if looking at the dish head-on), and the skew for 74 CW (based on where I am), but I'll just forgoe the original skew setup for 103 (so I won't have any CCW rotation to begin with), and will just skew a bit CW from 0 for 103 to get NBC.

So for example, if originally 103 should be skewed 18 CCW, but for NBC it needs to be rotated 25 degrees CW to match 74 (H2), I should just go 7 degrees CW from 0 degrees (straight alignment for the LNB). This should work I think.

You will still be off. You have to make the adjustment when the dish is in position at 110, then adjust the LNB to the skew for 74. Your method would only account for 7 degrees. For example, 82 for me is 1.1 skew, 74 is -7.4 skew (8.5 difference between the two), 110 is 27.5 skew. Using your method, the skew of 103 would have changed to 19 (27.5-8.5) whereas the skew when the dish is at 110 has to be -7.4.

 

[TreyWingbat]

But I'm referencing my adjustments based on 103 having no skew at all (0 degrees) for me (because I haven't set it up properly), just like the centre LNB is when the motor is at 0. So however many degrees the LNB skews from 0 to when it reaches the motor position for 74 (H2), I'll skew the same amount from 0 for 103, no?

The other thing that's interesting is that on the rail, the LNB's are opposite of how the dish rotates. So when the dish moves to the east from 110 to 74, it rotates to the right (while looking head-on), but the LNB for 119 is offset to the right of 110... that's because of the way the signals bounce off the dish (backwards) I guess though.

 

[Keith Brannen]

But I'm referencing my adjustments based on 103 having no skew at all (0 degrees) for me (because I haven't set it up properly), just like the centre LNB is when the motor is at 0. So however many degrees the LNB skews from 0 to when it reaches the motor position for 74 (H2), I'll skew the same amount from 0 for 103, no?

The other thing that's interesting is that on the rail, the LNB's are opposite of how the dish rotates. So when the dish moves to the east from 110 to 74, it rotates to the right (while looking head-on), but the LNB for 119 is offset to the right of 110... that's because of the way the signals bounce off the dish (backwards) I guess though.

Last comment first, yes it is all backwards! Not only what you mention, but also if the satellite is higher in the sky than your centre LNB, the LNB for it has to be lower than your centre LNB on your dish. All is backwards!

With a zero reference for both of your LNBs, for example in my case, when the dish would hit 110 both LNBs would be at 27.5 skew (in other words the zero position has shifted 26.4 from a perpendicular line to the ground-since 82 for me is 1.1).

If at zero position for you (82) and you skew the 103 LNB -7 degrees, that is exactly how the LNB should look when the dish is at 110 (whereas your centre LNB will have "leaned over" 25/26 degrees).
In other words, the 103 LNB should almost be straight up and down (a slight tilt) when the dish is at 110. That's why it is easier to make the adjustment when the dish is at 110.

 

[TreyWingbat]

Not too many people use multiple LNB's on a motorized setup, that's for sure! But of course I'm trying to for certain cases like this NBC Mux. Btw, I'm in the same area as you Keith (southwestern Ontario).

But I think we're on the same page... if 74 (H2) degrees is 7 degrees CW from 0 (based on it being straight at 82 or 0 skew), I would make the 103 LNB 7 degrees CW as well from 0, BUT when the dish is stationed at 110 of course (and not 82, otherwise, 103 will have skewed more than it should have when I do rotate to 110).

 

[Jim S.]

Does anyone know whether the replacement satellite is REALLY not going to be put in place until mid-2012, as the press release said, or whether that's a typo? It's been at 77 for testing for quite a while now. I haven't seen any reports of channels on it, but I've seen reports of unmodulated test signals.

 

[Keith Brannen]

Not too many people use multiple LNB's on a motorized setup, that's for sure! But of course I'm trying to for certain cases like this NBC Mux. Btw, I'm in the same area as you Keith (southwestern Ontario).

I figured we had at least close to the same longitude due to 82 being your true south satellite!

But I think we're on the same page... if 74 (H2) degrees is 7 degrees CW from 0 (based on it being straight at 82 or 0 skew), I would make the 103 LNB 7 degrees CW as well from 0, BUT when the dish is stationed at 110 of course (and not 82, otherwise, 103 will have skewed more than it should have when I do rotate to 110).

Yes, it will be easier to do it once the dish is stationed at 110 (and as I said, the LNB will almost straight up and down, with a slight lean). Once you get the signal, it will be easy to peak with slight changes to the skew, as I have found that just a bit of an extra twist one way or the other can boost the signal quality, or settle down a varying signal quality, of the target transponder that you want.

 

[Keith Brannen]

Does anyone know whether the replacement satellite is REALLY not going to be put in place until mid-2012, as the press release said, or whether that's a typo? It's been at 77 for testing for quite a while now. I haven't seen any reports of channels on it, but I've seen reports of unmodulated test signals.

LOL! If it is too soon, all that TreyWingbat and I have been discussing will be for naught!

Actually, I do hope it is a lot sooner than mid-2012, and hopefully some of the NBC transponders (like the one I only get a hint of now and again) will be a lot stronger!

 

[TreyWingbat]

It's funny Keith, I always thought about doing things when the dish was stationed at 110, but I kept referencing 82 because I was talking about the 0 skew point and the fact that I haven't setup the LNB for NBC with any skew at all, but yeah, in the back of my mind, I knew I want to do the skewing from 110 with the LNB offset at 103 on the rail... because here the NBC LNB acts like it's own stationary dish the way I have things set up. I guess I just never said it outright and put you through a bit of stress (sorry). But I just want to mirror what I see at 74 in terms of skew at 103. Now it's time to go try it out... not much daylight left.

 

[Keith Brannen]

It's funny Keith, I always thought about doing things when the dish was stationed at 110, but I kept referencing 82 because I was talking about the 0 skew point and the fact that I haven't setup the LNB for NBC with any skew at all, but yeah, in the back of my mind, I knew I want to do the skewing from 110 with the LNB offset at 103 on the rail... because here the NBC LNB acts like it's own stationary dish the way I have things set up. I guess I just never said it outright and put you through a bit of stress (sorry). But I just want to mirror what I see at 74 in terms of skew at 103. Now it's time to go try it out... not much daylight left.

Hey, no problem, glad to help talk it through. And, you can work in the dark, have done it myself (probably too many times!) just need a good light (once strapped a lamp, minus the lampshade, of course, to the mount of one dish so I could work on another)! Good luck!

 

[TreyWingbat]

Well, some success... I placed the LNB in the proper position in terms of the offset on the rail as much as possible by checking out other channels on 103. Then I started playing around with the skew, and I got the NBC tp (11880) to come in at about 62 percent. I couldn't get it too much higher. I tried scanning 11880 in, and some channels scanned in (as NBC East and Central). But the picture wouldn't come in on my AZ Box... I think it was trying to (I could hear blips), but I guess the signal quality wasn't quite there. If I push up on the LNB a bit to make it seem like I'm adjusting the elevation of the dish, the quality jumps up a few points.

I then went to check on 11840 not really changing anything physically, and things scanned in there fine at 66 percent! NBC Occasional feeds scanned in, and on one of them right now, Leno (in HD) is on.

But the question is, how strong does the signal have to be (at least on 11880) for the picture to come in (I guess every box varies though)?

 

[Keith Brannen]

Well, some success... I placed the LNB in the proper position in terms of the offset on the rail as much as possible by checking out other channels on 103. Then I started playing around with the skew, and I got the NBC tp (11880) to come in at about 62 percent. I couldn't get it too much higher. I tried scanning 11880 in, and some channels scanned in (as NBC East and Central). But the picture wouldn't come in on my AZ Box... I think it was trying to (I could hear blips), but I guess the signal quality wasn't quite there. If I push up on the LNB a bit to make it seem like I'm adjusting the elevation of the dish, the quality jumps up a few points.

I then went to check on 11840 not really changing anything physically, and things scanned in there fine at 66 percent! NBC Occasional feeds scanned in, and on one of them right now, Leno (in HD) is on.

But the question is, how strong does the signal have to be (at least on 11880) for the picture to come in (I guess every box varies though)?

On my AZBox 11760 is at around 70, 11840 at 72, and 11880, I only get a hint of a signal now and again (103 is on a 80cm, about 3 1/2 degrees off-centre - no centre LNB, 97 is about 2 1/2 off-centre, moved 97 off-centre to boost 103 a few extra points). These muxes do require a fairly strong signal before they come in, and, if I recall correctly, do start to drop out/pixelate if they drop below the mid-60s (so your 11880 readings/experience seem right to me).

 

[TreyWingbat]

I scanned in 11760 as well, and it's in the mid-60's. I can't get 11880 right now whatsoever. I thought I had it earlier for a bit, but right now, there's 0 quality. I guess that is the toughest to get. But it's still interesting to see what's on these NBC channels. Another question, how come the centre channel audio is very faint for some programs... is it supposed to be like this, or am I missing something?

 

[Keith Brannen]

I scanned in 11760 as well, and it's in the mid-60's. I can't get 11880 right now whatsoever. I thought I had it earlier for a bit, but right now, there's 0 quality. I guess that is the toughest to get. But it's still interesting to see what's on these NBC channels. Another question, how come the centre channel audio is very faint for some programs... is it supposed to be like this, or am I missing something?

You have to hunt through the various audio selections for each channel to find a good mix (have seen some with music only, voices only, various other mixes and different levels, etc.). And then they can change!

 

[TreyWingbat]

I see. I was trying to play around with some of the audio setup in the AZ Box, but I still couldn't get the centre channel to come in. There's about 6-7 selections, so I guess there can be a lot of combinations.

Another quick question... I guess the closer you are to the centre of the dish with the LNB, the better the signal will be, right? If so, I can move the NBC LNB more towards the centre, and that means I'll have to have the motor stop at around 106 or 107 degrees for NBC. But if it helps the signal quality, I'll definitely do this.

 

[Keith Brannen]

I see. I was trying to play around with some of the audio setup in the AZ Box, but I still couldn't get the centre channel to come in. There's about 6-7 selections, so I guess there can be a lot of combinations.

Another quick question... I guess the closer you are to the centre of the dish with the LNB, the better the signal will be, right? If so, I can move the NBC LNB more towards the centre, and that means I'll have to have the motor stop at around 106 or 107 degrees for NBC. But if it helps the signal quality, I'll definitely do this.

Yes, the closer to the centre the better. Since you have an elliptical dish (which are better for multiple LNBs), you might not see a great increase in signal (not as great as moving an LNB closer to the centre of a circular dish), but every little bit will help with these marginal signals.

 

[TreyWingbat]

Ok, I'll try it out and see how it goes. I won't have time to do much the next two nights, but I'll keep you posted! Thanks to you Keith and everyone else for your help!

 

[TreyWingbat]

I found some time just before my evening activities, and I did move it closer to the centre. I saw a few percentage points jump in the signal quality I believe, but nothing major. But everything is locked in place now.

Next thing might be to try out a C-band LNB with a conical scalar ring!