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Admin1
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Reply #1 - Sep 21st, 2009 at 12:42pm
What was the polarisation adjustment set to ?
Looking at the image the angle is about -10 deg. I calculate more like -25 deg for Portugal. Anticlockwise, while facing towards the satellite in the sky, is correct, as Portugal is to the west of the satellite orbit position.
Regarding use of a pole to obtain view of the satellite, this should be necessary only if the obstruction is very close. Try to avoid a long pole if possible as it makes a hazard for the installer and it is very difficut to do the precision pointing work when the dish is high up like that. Precision pointing is still needed even if the satellite signal is very strong. Ka band needs a big rain margin, for both uplink and downlink so spend at least 30 minutes peaking up after you have found the satellite. Accurate polarisation does matter, otherwise the service will fail when new cross-pol transponders come on-line next year with Ka-Sat.
The scew is at 102 deg. If you move it to 115 as suggested then the signal gets worse. Spent nearly an hour peaking signal to ensure the best possible.
Obstructions are very close. Lots of trees on site and house is not only situated in a valley with mountains on every side, but also tucked into the the mountain side itself making a normal wall mount impossible to use. This is quite normal for Algarvean homes.
Although pole looks long, back of house is tucked into mountainside, so pole is actually shorter than it looks. Secured tightly into the house wall and indeed into the ground.
Clients Sky dish is on a similar pole and has never moved he tells us.
We appreciate your assistance but to give you more insight into the site. Trees everywhere, large and small, olives, eucalypes, pines, all within a few metres of the house. There was also no suitable place to mount the standard bracket for the dish. We tried in one spot which looked suitable and due to the trees and valley configuration were not able to get a signal on the spectrum analyser after a whole day of trying!!
We know a two way system needs a better alignment than a television dish as data is both sent and received. This is why we use a spectrum analyser to configure the best signal possible rather than relying on the basic handheld meters. We use the Horizon HDSM USB PLUS with a Custom Carrier to pinpoint the satellite signal. We will shortly be investing in the Horizon Horizon HD-TC8 which is specifically designed for use with Tooway on Hotbird 6.
Mounting the dish on the ground was not feasible due to family animals who have the run of the area, plus other wildlife which frequently comes in from the surrounding area.
I have also been in contact with Bentley Walker and have the statistics for both this system and our own. Their email today confirms:-
‘As you can see from the attachments both sites are well clear of FAP penalty and the signal levels are now well within specified limits. Both sites should be working well.’
Perhaps you have never needed to use a pole such as this. You never know you may need to in the future? The client is extremely happy, Bentley Walker are happy with the signal levels (RX and TX), and the area is not renowned for high winds.
We each have different opinions and way of doing things, but at the end of the day, the system is working very well.
