Same bird, different aim for 2 freqs on AMC1

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Panavision

SatelliteGuys Pro
Original poster
Jan 23, 2007
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St. Louis Park, Minnesota
My 90cm dish is aimed at AMC1 and I get NBC pretty well, but Safeway is at 0%. If I pan the dish east a hair, I get Safeway great, but NBC goes away. How can two services on the same satellite require different aiming? Thoughts?
 
I think it has to do with the smaller dish...remember, most people these signals are intended for use huge dishes.

I see that allot on C-Band....get one signal at 75 but another at 0..move it a hair (literally 1/16" tops) and 2nd signal is at 50 but 1st is at 20...I think its due to a smaller than normal dish
 
Don't forget AMC1 has a very unusual skew.

Right now I have a 90cm fixed dish at AMC 1 but before, I had a 80 cm pointed at AMC1 and I was able to receive NBC and SSN, but only with an extra skew of about 30 degrees.

Also from Iceberg's review of the toroidal dish:

103 was the first one that amazed me. Remember that AMC1's skew is goofy so I skewed the LNB and to my amazement, I got 99 on Pentagon. I also got about 10 feeds that I have NEVER seen on AMC1 (mainly due to the LNB being off). So I was very happy.
 
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Odd Skew on AMC 1 at 103.0°W

You know, I've looked all over Lyngsat, Global-CM, and the FTAlist sites, and on none of them do I find reference to the odd skew.
Not on the pages I visit, anyway. (the obvious pages, linked above)
And if they do mention it , buried away on some other page, it's useless!

So, how am I going to remember this is the one Ku bird that's twisted?
And any idea why it's off kilter?
What about its C-band side? Is it straight arrow, or what?


Other than hearsay , this is the only authorative comment I've seen on the subject, and it's not even from the satellite provider:
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).
 
So, how am I going to remember this is the one Ku bird that's twisted?
That is the only one to remember
And any idea why it's off kilter?
have no idea

What about its C-band side? Is it straight arrow, or what?
C-Band is correct. My C-Band skew is around +9 for AMC1 which is what most of the satellite aiming sites show

Other than hearsay , this is the only authorative comment I've seen on the subject, and it's not even from the satellite provider:
and that link is wrong too. It shows Minneapolis at
City State Lat Long El Az Comp Polarization
MINNEAPOLIS MN 44.98 93.26 37.29 193.65 189.15 16.39

Sadoun shows it as +9.6 skew when in fact its around -18 for AMC1 KU (about the same as SBS6)
 
and that link is wrong too. It shows Minneapolis at
City State Lat Long El Az Comp Polarization
MINNEAPOLIS MN 44.98 93.26 37.29 193.65 189.15 16.39

Sadoun shows it as +9.6 skew when in fact its around -18 for AMC1 KU (about the same as SBS6)

That's strange, it corrected mine by subtracting about -15 off of what should be the normal skew, yet it adds +7 to what your normal skew should be? Seems like they have a slight re-calculation problem!

As I said above, even the -15 wasn't enough for me. I just checked it and it is slightly less than -30 off what it should be, and closer to the skew of AMC6, rather than SBS6!

Instead of saying take -25 or so off of the skew, may be we should just tell people to start with the same skew as they would use for SBS6.
 
It took me a while to figure out the skew on AMC1. Every once and a while I'll readjust it just to be able to get a high enough quality level out of NBC. This is one of the most difficult services for me to pull in because of the 7/8 FEC. Not to mention I'm in an apartment and because of the direction my balcony faces, part of the dish is underilluminated. Thanks for the responses!
 
from the horse's mouth

Polarization Offset
26.0o CCW (viewed from the earth)This is from SES-Americom website on the specs for AMC1 KU.
I d/l a pdf of the technical stuff maybe it will tell the WHY its skewed differently!
 
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