nopfusch
Regular Member
- Joined
- Sep 11, 2005
- Messages
- 40
- Reaction score
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- Age
- 83
- My Satellite Setup
-
sAT.: EechostarDVB 1000Ci2 (no 7 tears old and faulty), one Analogue receiver threshold -3dB, even older but still in good working order, 3.6m mesh dish with positioner, California feedhorn with mech. polarizer and C- and Ku- Band LNBs.
PC1 P4 2.2GH
- My Location
- South Africa, Johbg., 26.2S, 28.1 E
Hi,
may I post 2 threads here, regarding one item: LNB skew setting?
When I read lungsat or SATCOdx settings, they are for Dishes/LNBs situated in the northern hemisphere.
And the Skew setting for the LNB? They have none but with digging around I discovered exactly opposing answers.
With the aid of the Dish-pointer (great-) program I did the following:
I took "our" satellite and recorded the following data from the dish-pointer:
City........................Satellite: Intelsat7/10 .........................City
Location Longt. ................Location Longt. .................Location Longt.
Istanbul 28.9° .....................68.5° .......................Hongkong 114.1°
Latit. 41.04° ......................................................Latit. 22.4°
LNB skew -36.2 ...................................................LNB skew 60.0°
southern hemisphere:
Germiston South Africa 28.16° .............................Perth 115.8°
Latit. -26.16° ......................................................Latit. -39.95°
LNB skew 52.8° ..................................................LNB skew -49.7°
The difference between Germiston and the Satellite is approx. 40°. So I added to the longitude of Intelsat 7/10 (old PAS 7/10) also 40°. But in the south at this longitude is the Indian Ocean so I went to Perth and in the North is Hongkong, which gives then 50° difference in Longitude between the Satellite and Cities. Not exactly symmetrical to Germiston/Istanbul but for this exercise OK.
Conclusion: the LNB skew depends if the relevant location is before or after the Longitude of the Satellite, when looking from 0°. But with the dish-pointer that problem is now solved.
In a feed horn of another SATDXer, the "local" Satellite (PAS 7/10) can only be viewed in the extreme skew setting either 0° or plus and minus
90° in C- and Ku-Band. The feed horn is exactly aligned to be in line with the dish pivoting axis (Polar axis) and there is no more possible settings. As the equipment is 2ND hand, it might have been tampered with, although it doesn't look like.
I removed the feed horn and looked into the same. The feed horn has the diverter plate in, to receive circular polarized signals. Now the pick-up probes for the C-Band (which rotate when changing the skew) are just looking past the diverter plate . That could maybe explain the C-Band. But the pick-up probes for the Ku-Band is separated and before the diverter plates. And no matter what I tried, It comes back to this setting 90-0-
90 degrees.
And at the Location here, it should be 52° but for which polarity?
I assume it is in the center of both polarities but then: 52°
+ 45° is out of range (can't be >90°). Where is my or the mistake?
Thanks.
The dish pointer and other prog's overdoing the sizes of dishes to receive that Satellite here: 120 cm! a 40 cm dish delivers good pic's.
And the SATco Receivable program says it needs here a 900 cm (9 meters!) dish to receive the C-Badr. My friend with a 3.2m dish has excellent pic's with a quality of > 75% !
may I post 2 threads here, regarding one item: LNB skew setting?
When I read lungsat or SATCOdx settings, they are for Dishes/LNBs situated in the northern hemisphere.
And the Skew setting for the LNB? They have none but with digging around I discovered exactly opposing answers.
With the aid of the Dish-pointer (great-) program I did the following:
I took "our" satellite and recorded the following data from the dish-pointer:
City........................Satellite: Intelsat7/10 .........................City
Location Longt. ................Location Longt. .................Location Longt.
Istanbul 28.9° .....................68.5° .......................Hongkong 114.1°
Latit. 41.04° ......................................................Latit. 22.4°
LNB skew -36.2 ...................................................LNB skew 60.0°
southern hemisphere:
Germiston South Africa 28.16° .............................Perth 115.8°
Latit. -26.16° ......................................................Latit. -39.95°
LNB skew 52.8° ..................................................LNB skew -49.7°
The difference between Germiston and the Satellite is approx. 40°. So I added to the longitude of Intelsat 7/10 (old PAS 7/10) also 40°. But in the south at this longitude is the Indian Ocean so I went to Perth and in the North is Hongkong, which gives then 50° difference in Longitude between the Satellite and Cities. Not exactly symmetrical to Germiston/Istanbul but for this exercise OK.
Conclusion: the LNB skew depends if the relevant location is before or after the Longitude of the Satellite, when looking from 0°. But with the dish-pointer that problem is now solved.
In a feed horn of another SATDXer, the "local" Satellite (PAS 7/10) can only be viewed in the extreme skew setting either 0° or plus and minus
90° in C- and Ku-Band. The feed horn is exactly aligned to be in line with the dish pivoting axis (Polar axis) and there is no more possible settings. As the equipment is 2ND hand, it might have been tampered with, although it doesn't look like.
I removed the feed horn and looked into the same. The feed horn has the diverter plate in, to receive circular polarized signals. Now the pick-up probes for the C-Band (which rotate when changing the skew) are just looking past the diverter plate . That could maybe explain the C-Band. But the pick-up probes for the Ku-Band is separated and before the diverter plates. And no matter what I tried, It comes back to this setting 90-0-
90 degrees.
And at the Location here, it should be 52° but for which polarity?
I assume it is in the center of both polarities but then: 52°
+ 45° is out of range (can't be >90°). Where is my or the mistake?
Thanks.
The dish pointer and other prog's overdoing the sizes of dishes to receive that Satellite here: 120 cm! a 40 cm dish delivers good pic's.
And the SATco Receivable program says it needs here a 900 cm (9 meters!) dish to receive the C-Badr. My friend with a 3.2m dish has excellent pic's with a quality of > 75% !