SatSig topic:

29 sig in Iraq

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Mar 28^th, 2009 at 2:29pm

Greetings all,

I am trying to set up a Bentley-Walker HX50 system near Bayji, Iraq. My problem is that I cannot get past 29 signal on my modem. I've double-checked my modem settings from what I was given, we're spot on. We've also tweaked this satellite 3 different times, trying to get a lock.

I tried hooking the satellite meter up to the dish and I can only get a 72 udb signal from w3a Africa, is that good? I haven't managed a lock with the sat meter on w3a, but yesterday I did get an AtlanticBird satellite locked just by coincidence (switching through satellites on the meter).

I'm sure I am missing something simple here, already had one of the guys on my FOB who has a satellite up and running come over and take a look. He helped us fix our dish up nice, but still no lock. I would appreciate any and all help you can give, and if you tell me to check my modem again I most certainly will. Thanks in advance.

Peace,
Greg

Mar 28^th, 2009 at 6:21pm

I was sorta hangin' back here, waitin' for BW to respond - but maybe being Saturday has something to do with it. I've seen this 29 business before - often as a result of getting incorrect satellite parameters (modem settings) from the provider.

First suggestion is simply to contact BW direct to confirm parameters. Short of that, play with different parameter values - until they respond. You might get lucky. The SBC file in the modem should contain more than one set of parameter options, from which you can obtain some representative numbers. As long as the TX cable remains disconnected until you obtain a good RX signal, you're not going to hurt anybody or anything playing with the modem settings.

//greg//

Mar 28^th, 2009 at 8:32pm

Hi, Greg, and thanks for the reply.

Well I went out again tonight when the winds were calm, but there is still a cloudy sandstorm going on. I rechecked my settings from when I had been playing around with them earlier, trying every trick I could read on this forum.

After a few hours of changing and checking a whole bunch of things, my maximum signal on my modem is now a whopping 18 out of 100. Looks like I got that modem problem fixed.

I do have a question, though, if anyone can answer it. I know that both W3A Africa and W3A Europe are on the same meridian, but would it matter if I am getting signals crossed, ie aiming at the wrong bird?? My sat meter shows different readings (at least 2-3 udb) between the two.

Also, could the fact that I bought my coaxial cables from the local national store on my fob do something with the signal? I understand that copper is copper, but one of the other guys with satellite internet mentioned a difference to me a month or so back when I talked to him. Alas, he is on leave now so I cannoot confirm what he meaned.

Any help is, as always, appreciated.

Peace,
Greg

Mar 28^th, 2009 at 11:02pm

W3A is a single satellite, at 7 deg East orbit position, with both a Europe/Mid East coverage beam and African coverage beam. The Europe/Mid East beam includes Iraq. The Africa beam does not cover Iraq.

Bentley Walker have two HX hubs, one in each beam, and each with their particular outlink carrier frequency, symbol rate and polarisation.

A signal level of 18 is very poor, and could be coming from any satellite. Readings up to 29 are just power and you will get readings up to 29 on any and all satellites. Powerful satellites will max out at 29. Only if you are on the correct satellite and polarisation and have matching frequency and symbol rate etc set in the modem configuration will the HX modem lock onto the carrier and give a signal reading between 30 and 100, typically 90.

I believe the downlink polarisation you want is horizontal so your feed polarisation starting position is with the LNB side arm at the top. I guess that your polarisation adjustment angle is about +45 deg, so rotate the exact amount clockwise, while facing towards the satellite. Use the calculated angle and add +3.5 deg. During commissioning BW may help you to make a small polarisation adjustment to get into the narrow cross-pol null.

See: Sat dish pointing in Iraq.

The picture below shows how to set the beam elevation angle for a 1.2m prodelin dish with 3 axis positioner. The beam direction is exactly at right angles to the polarisation plate behind the dish. As shown, the beam elevation angle, 48 deg, is not the same as the angle you want, which will be more like 35 deg. Get your required beam elevation using the Iraq map dish pointing page above.

If you need an inclinometer print this page "How to make an inclinometer" and cut it out.

You will definitely find the satellite the first time you swing the dish boldly sideways around the approx magnetic compass azimuth bearing.

Best regards, Eric.

Mar 29^th, 2009 at 3:08pm

greetings all,

Well I went out this afternoon and messed with everything again, finally got a lock. Peaked a 93 earlier, but my modem has been messing up on me and now I am sitting at an 85. I'm sure it's weather related, everyone on the FOB was out last night somehow.

But I wish to extend my thanks to everyone here.

One last thing: Anyone know how to call BW from an Asiacell phone?

Peace,
Greg

Mar 30^th, 2009 at 11:41am

Hi Greg,

I understand your modem should be activated now. If you have any problems or questions please let us know.

Regards

Paul
Bentley Walker Ltd