91w, 97w & 123w on 75e Dish?

[Babadem]

Is it possible to have 91w, 97w and 123w on a 75e dish? I know 91w and 97w are possible, but how far can I go from 97w torwards 123w on this dish?

 

[SatPhreak]

32 degrees of seperation there. I wouldn't even try it because it probably won't work. I don't think you could get that much seperation on any dish except a toroidal (and those are rated for 40 degrees because of the design of the dish.)

 

[tvropro]

Is it possible to have 91w, 97w and 123w on a 75e dish? I know 91w and 97w are possible, but how far can I go from 97w torwards 123w on this dish?

You can't do that big of a spread on your dish. You can do 123 and 129 though. I will be attempting that on my 81e ADTH dish very soon. My second .4 Geosat LNBF should be here tomorrow.

 

[scottc98]

Well.....I've got 14 deg seperation right now on my 75e (channelmaster). IS-9 and AMC6. Its focused on IS-9 with AMC6 offset. It works pretty good. GBN is still 70+ Quality. I probably would go that much further on linear sats. Back in the day when I had Bev and dish, I was able to do 119, 110, 101 (just for measuing purpose), 91, 82. I later changed out the 119 and added 61.5. This was my pre-fta days when I was in California.

Your not going to get peak signal on the 75e as you would with one stationary but it works

 

[Keith Brannen]

Well.....I've got 14 deg seperation right now on my 75e (channelmaster). IS-9 and AMC6. Its focused on IS-9 with AMC6 offset. It works pretty good.

I think AMC6 must be a fairly strong satellite, as I have it about 12 degrees off-centre, and, like you, get very decent signals from it. On the other hand, I also use to have G26 on the same dish and it was about 9 degrees off-centre, and signals were not so good, especially on the horizontal transponders. I recently moved G26 off of that dish and put it on a 60e (at the centre) and really boosted the signals.

Going from 91 to 123 would be too far, even if you centred the dish between the two so it would be 16 degrees off-centre for both satellites, I would think 123 (which has some weak transponders) would be badly compromised, if not non-existant, at that distance. As well, I certainly wouldn't want G25 (97) at 10 degrees off-centre!

 

[Babadem]

Very interesting points. What of 91w, 97w and 103w, would that combinantion be ok?

 

[Wescopc]

Should work, you may need the tiny LNB's like SatelliteAV sells to get the centerline spacing for 6°.
Bob

 

[scottc98]

6 deg spacing should be fine. The prob you will run into is the LNB itself blocking you from fine tuning. Smaller LNBs (as suggested above) should help you out in that dept. I had 74 and 79 on the same dish and that was my biggest prob. If you are going to go with 103, remember the weird skew for the H pol.

 

[tvropro]

Should work, you may need the tiny LNB's like SatelliteAV sells to get the centerline spacing for 6°.
Bob

The Geosat pro GSL1s-Bullet is very small and work's well. I just got my second one it's sitting right in front of me now. It fits in the palm of my hand. Now I need figure out how to bracket the sucker to get 129 on my G-10 dish.

 

[Babadem]

6 deg spacing should be fine. The prob you will run into is the LNB itself blocking you from fine tuning. Smaller LNBs (as suggested above) should help you out in that dept. I had 74 and 79 on the same dish and that was my biggest prob. If you are going to go with 103, remember the weird skew for the H pol.

Not really sure. Since my Dish has a skew setting, should I be concerned with skewing the LNB?

 

[Keith Brannen]

Not really sure. Since my Dish has a skew setting, should I be concerned with skewing the LNB?

Yes, you will have to skew the LNB as well as it is really off from what it should be. I have 91, 97, and 103 on one dish (pictured below left to right, plus Echo8 at 110). The skew for my area is 10.5 (91) and 16.5 (97), and as you can see 103 is in the minus!

 

[Babadem]

Yes, you will have to skew the LNB as well as it is really off from what it should be. I have 91, 97, and 103 on one dish (pictured below left to right, plus Echo8 at 110). The skew for my area is 10.5 (91) and 16.5 (97), and as you can see 103 is in the minus!

I succeeded in installing 91w and 97w yesterday, but for the life of me I could not get 103w. I got signal from 105w, 119, even 101w, but not 103w. I tried twisting and angling the LNB but nothing on 103w. Oh! BTW my 75e globecast dish measures 36"X27". My location is North Lat:42.12 and West Long:71.04. Based on my location what should be the skew on 103w? How do i know if the skew on the LNB is right without having the do trial and error?

 

[Mr Tony]

AMC1 (103W) is an oddball skew on KU. You take what the skew normally is and to optimize signal, turn it 25 degrees OPPOSITE of that

So as an example, AMC1 here in Minneapolis (45N 93.5W) the skew should be +9.6 (so if standing in front of the dish facing it, the coax connector is at about 5:30 on a clock)...however to optimize quality (and to overcome that skew) I turn it 25 degrees clockwise...so now the connector looks like its at 7:30..the skew looks almost the same as SBS6

 

[Mr Tony]

Here is a great picture of what I am talking about

The farthest left LNB is on ANikF1 for StarChoice and the skew is right...the LNB to the right of it is AMC1...look at the skew (technically on the T90 dish the LNB's should be on the 0 spot on the holder...the LNB for AnikF1 skew is probably off by 2 degrees of zero or so

(by the way...disregard the 3rd LNB skew...that wasn't hooked up at the time)

 

[Babadem]

Here is a great picture of what I am talking about

The farthest left LNB is on ANikF1 for StarChoice and the skew is right...the LNB to the right of it is AMC1...look at the skew (technically on the T90 dish the LNB's should be on the 0 spot on the holder...the LNB for AnikF1 skew is probably off by 2 degrees of zero or so

(by the way...disregard the 3rd LNB skew...that wasn't hooked up at the time)

Thanks Ice! My LNB Angle is 30.3. Using your clock analogy, what dial on the clock should i be looking at?

 

[Mr Tony]

so for AMC1 the skew should be 30.3? + or -?

Whatever it shuld be turn it 25 or so degrees opposite that...so if its +30.3 go to that first, then turn it 25 degrees off that (so it shuld be like at +5 or so)

 

[Keith Brannen]

Thanks Ice! My LNB Angle is 30.3. Using your clock analogy, what dial on the clock should i be looking at?

This site, from one of the companies using the satellite, gives an adjusted skew for AMC1 for cities in the US and Canada:
Microspace - Pointing Info

However, I found that their adjustment (about -15 for my location) was not enough, and mine is at least -25 (or more).

Another factor, since you are using an elliptical dish, you already have the dish skewed for G25 (97). Skew for another satellite is based on a plumb vertical line from the ground. If your LNB holder has been tilted so that its zero mark (if there is one on the LNB holder) is also skewed, then you have to minus the skew of G25.
In other words: skew for AMC1 minus skew for G25 equals skew from the zero mark on the LNB holder.

 

[Babadem]

This site, from one of the companies using the satellite, gives an adjusted skew for AMC1 for cities in the US and Canada:
Microspace - Pointing Info

However, I found that their adjustment (about -15 for my location) was not enough, and mine is at least -25 (or more).

Another factor, since you are using an elliptical dish, you already have the dish skewed for G25 (97). Skew for another satellite is based on a plumb vertical line from the ground. If your LNB holder has been tilted so that its zero mark (if there is one on the LNB holder) is also skewed, then you have to minus the skew of G25.
In other words: skew for AMC1 minus skew for G25 equals skew from the zero mark on the LNB holder.

Thanks for the info. I am still a little bit confused about this logic. I may have to read/research more on this. Meanwhile, i would appreciate more info.

 

[Keith Brannen]

Thanks for the info. I am still a little bit confused about this logic. I may have to read/research more on this. Meanwhile, i would appreciate more info.

I'll use my numbers for 91, 97, & 103 (and assume that 103 was not a wacky skew, but as it should be) to try to explain. Therefore the skews would be 10.5, 16.5, and 21.9. If I had a bracket for the LNBs that ran parallel to the wide part of the elliptical dish, the top of the LNB holders would be zero (and be marked as zero). As soon as you skew the dish to 97, or 16.5 skew, the zero mark on all LNB holders is skewed 16.5. The LNB for 97 remains at the zero mark as that is its correct skew. 91 skew is only 10.5. Therefore, to skew it only 10.5 you have to skew it -6 from its zero mark (10.5-16.5). For 103, you would have to skew it 5.4 from its zero mark (21.9-16.5).

Hope that helps (and doesn't add to the confusion).

 

[Babadem]

I'll use my numbers for 91, 97, & 103 (and assume that 103 was not a wacky skew, but as it should be) to try to explain. Therefore the skews would be 10.5, 16.5, and 21.9. If I had a bracket for the LNBs that ran parallel to the wide part of the elliptical dish, the top of the LNB holders would be zero (and be marked as zero). As soon as you skew the dish to 97, or 16.5 skew, the zero mark on all LNB holders is skewed 16.5. The LNB for 97 remains at the zero mark as that is its correct skew. 91 skew is only 10.5. Therefore, to skew it only 10.5 you have to skew it -6 from its zero mark (10.5-16.5). For 103, you would have to skew it 5.4 from its zero mark (21.9-16.5).

Hope that helps (and doesn't add to the confusion).

Thanks Keith Brannen. As soon as I get the opportunity, I will try this approach and will keep you updated.