Need help with amc9 (1 Viewer)

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hotdog842

Thread Starter
SatelliteGuys Family
Oct 15, 2008
49
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I have a 10" perfect 10, cal amp .7 lnb, coolsat 5000. I spent 3 days tweaking the dish. Manually set up sat in the menu 11774H 4232, and 11735H 4440. I have a 87 signal on 11774 and get a perfect picture but I can't get any signal on 11735. I tweak the allignment to get max signal on this sat. What am I missing? could my dish not be good enough? I heard these dishes are not that good for Ku. Would a new smaller dish be better? What is the minimum size I should look at.

Thanks
 

brentb636

SatelliteGuys Pro
Jun 24, 2006
4,278
6
5 miles N of Saugatuck, Mi
Did you say 10 INCH dish ? I can just get that 11735 tp on my 1.2m dish. Can't get it at all on my 36" dish. That 11735 tp is unusually weak. Normally I would say that a 36" dish should give adequate results for anyone in the central 3/4 of the US , with a 1 meter dish covering everybody else. That gives some room for rain fade .
You are seriously "under-dished", I'd say.
:)
 

Mr Tony

SatelliteGuys Pro
Supporting Founder
Nov 17, 2003
289
38
Mankato, MN
Only reason I can think of as to why it doesnt come in is with a bigger dish KU needs to be spot on to work and that feed is notoriously low
 

guapoharry

SatelliteGuys Pro
Jul 19, 2006
1,423
0
32ºN 111ºW
That last three percent of Q was a royal pain...

On the motorized Fortec 90cm dish 11735H 4440 comes in at 61-63. No soap. 11774 comes in at 91-94. Kind of unstable. But that dish setup works OK for most sats, so I didn't want to mess with it...

I get RTN on a stationary ADTH 87CM dish. It was a real pain to set up. 11735H barely comes in at 66. 11774 comes in at 94. Both of these TPs are fairly steady after a lot of adjustment. Receiver: Coolsat 5000.

What I did was to find a way to repeatably measure dish adjustment for azimuth and elevation. After finding the satellite, I moved the dish back and forth in fixed increments. This was done while writing down the signal strength value from the receiver.

For example. I moved the azimuth west in 1/8 inch increments measured at the feed horn until the squality dropped off. After each move, I recorded the quality. Then I moved the azimuth back east. The signal locked again. After a number of increments, the quality dropped off again.

Then I temporarily set the azimuth half way between the positions where the signal would lock.

Then I repeated the procedure for elevation.

Then I repeated the procedure for skew. I started with marking a point on the LNB from a reference point on the LNB holder. This was done much as before. I rotated skew until the quality died. Another mark corresponding to the reference point was written on the LNB. Then the skew was rotated the opposite direction until the quality died again. Another mark was written on the LNB. The skew was set half way between the mark limits.

After that, I repeated the azimuth, elevation and skew adjustment method again. Once I found the best quality, I tried again, moving in 1/16" increments around the sweet spot. This was done until I could do no better.

An example of initial measurements on a one meter Prodelin pointed at G18 follow:

Code:
Azimuth

1 3/8
1 1/2 - 9-10
1 5/8 - 61-60-63
1 3/4 - 62-63
1 7/8 - 63-62
2     - 62-63
2 1/8 - 63-62
2 1/4 - 62-61-63
2 3/8 - 61-10
2 1/2 - 9-10
2 5/8


Elevation

3 1/8
3 1/4 - 8
3 3/8 - 60-09
3 1/2 - 60-63
3 5/8 - 63-62
3 3/4 - 63-64-62
3 7/8 - 63-64-62
4     - 61-63-60
4 1/8 - 9-10-60
4 1/4 - 8-6
4 3/8

Some pictures of doing this on a one meter Prodelin are attached.

Hope this helps.

After having said all that, the picture on RTN pixellates once in a while but it is watchable.

PS: For a BUD, I would try to verify that your feedhorn is at the focus. I have some ideas. But, having only set up one 1.8 meter dish, I'll let someone else suggest how to do that...
 

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Corrado

SatelliteGuys Pro
Apr 2, 2007
2,382
270
Hudson Valley Region, NY
AMC9 seems to be one of the most skew sensitive satellites that I have ever tuned to. Settings are critical and must be perfect.

On the upside, 83°W has a great look angle as compared to 123°W here in NY. More people might have a chance to get RTN now. Buildings and trees might be less of an issue. If only the signal was a little stronger.
 

tvropro

On Vacation
Mar 9, 2007
6,872
0
The perfect 10 was a pretty good dish but like with all mesh c band dishes they aren't that great on ku. I know my 90cm Primestar can rival most 10ft mesh dishes on ku. As far as AMC 9 and RTN goes all of us with better dishes are getting borderline to dropout on it because there uplink is running such a weak signal. Until they get more wattage in the cottage it is what it is, unless one wants to put up a 5 meter receive dish for ku.
 

tvropro

On Vacation
Mar 9, 2007
6,872
0
On the motorized Fortec 90cm dish 11735H 4440 comes in at 61-63. No soap. 11774 comes in at 91-94. Kind of unstable. But that dish setup works OK for most sats, so I didn't want to mess with it...

I get RTN on a stationary ADTH 87CM dish. It was a real pain to set up. 11735H barely comes in at 66. 11774 comes in at 94. Both of these TPs are fairly steady after a lot of adjustment. Receiver: Coolsat 5000.

What I did was to find a way to repeatably measure dish adjustment for azimuth and elevation. After finding the satellite, I moved the dish back and forth in fixed increments. This was done while writing down the signal strength value from the receiver.

For example. I moved the azimuth west in 1/8 inch increments measured at the feed horn until the squality dropped off. After each move, I recorded the quality. Then I moved the azimuth back east. The signal locked again. After a number of increments, the quality dropped off again.

Then I temporarily set the azimuth half way between the positions where the signal would lock.

Then I repeated the procedure for elevation.

Then I repeated the procedure for skew. I started with marking a point on the LNB from a reference point on the LNB holder. This was done much as before. I rotated skew until the quality died. Another mark corresponding to the reference point was written on the LNB. Then the skew was rotated the opposite direction until the quality died again. Another mark was written on the LNB. The skew was set half way between the mark limits.

After that, I repeated the azimuth, elevation and skew adjustment method again. Once I found the best quality, I tried again, moving in 1/16" increments around the sweet spot. This was done until I could do no better.

An example of initial measurements on a one meter Prodelin pointed at G18 follow:

Code:
Azimuth

1 3/8
1 1/2 - 9-10
1 5/8 - 61-60-63
1 3/4 - 62-63
1 7/8 - 63-62
2     - 62-63
2 1/8 - 63-62
2 1/4 - 62-61-63
2 3/8 - 61-10
2 1/2 - 9-10
2 5/8


Elevation

3 1/8
3 1/4 - 8
3 3/8 - 60-09
3 1/2 - 60-63
3 5/8 - 63-62
3 3/4 - 63-64-62
3 7/8 - 63-64-62
4     - 61-63-60
4 1/8 - 9-10-60
4 1/4 - 8-6
4 3/8
Some pictures of doing this on a one meter Prodelin are attached.

Hope this helps.

After having said all that, the picture on RTN pixellates once in a while but it is watchable.

PS: For a BUD, I would try to verify that your feedhorn is at the focus. I have some ideas. But, having only set up one 1.8 meter dish, I'll let someone else suggest how to do that...

I always tune through the peak on azimuth, elevation and skew then do the same the other way and split the difference. You want to be in the center of the box.
 

guapoharry

SatelliteGuys Pro
Jul 19, 2006
1,423
0
32ºN 111ºW
As far as AMC 9 and RTN goes all of us with better dishes are getting borderline to dropout on it because there uplink is running such a weak signal. Until they get more wattage in the cottage it is what it is, unless one wants to put up a 5 meter receive dish for ku.

I'm curious about this issue. Why is RTN borderline on AMC 9? I don't doubt that if the uplink power or some other issue results in a low Q at the satellite the transmit signal could be problematic. Also, the FEC is kinda low. But what about the following?:

Today when there was heavier than usual feed usage, RTN quality and stability went in the toilet for me. This was when the plane crashed in NYC.

After the feeds shut down, RTN quality and stability returned. Is this a coincidence, or a correlation?

Then I wondered what's the deal with AMC 9?

NASA spacecraft details.

If this is correct, AMC 9 used to be located at 85W, not 83W. It has C band transponders, but I don't see listings for their usage. Did this sat have problems?

Wonder what would happen if you scanned AMC 9 C-band with a BLSA?

Could neighboring transponders affect how I receive one with a marginal quality?

Sorry about asking a bunch of goofy questions. :p :hungry:
 
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