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Help! express Am22 satellite jeddah

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May 28th, 2006 at 7:56pm  
hi

I was tring to setup satellite internet from satconxion from spain and as the company said i bought a 1.8 m dish and tied to receive express am 22

freq 11481,h,42150

but unable to lock the signal

pls can any body help me ,i tried to lock signal using satfinder and even receiver..but failed..

the coverage ,aps say jeddah,saudi arabia eirp value 39db

but the particular freq above has spot beam on jeddah @ 47 db as from satcodx.com and lyngsat.com

where iam going wrong iam not able to get .

but the company says <1.8 m dih no reception gurantee

HELP ME PLS
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Eric Johnston
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Reply #1 - May 29th, 2006 at 12:19pm  
Check the receiver settings:  Freq=11481 MHz and Symbol rate 42150 Msps.   If the receiver needs you to input the frequency at L band make sure you have taken off the actual LNB local oscillator frequency.  e.g. 11481 - 10000 = 1481 MHz.   This assumes you have a 10 GHz LO LNB.

Dish set up:  You set the elevation and polarisation angles and boldly swing the dish around in azimuth to find the satellite. Then peak up.

Set the elevation angle using the scale on the bracket.  If no scale, read the instructions.  If it is an offset dish with the feed at the bottom the front face of the dish will probably be tilted backwards, by say 39 deg for a 61 beam elevation angle - but this depends on the dish offset angle (assumed here to be 22 deg, but this may be wrong for your dish) which is hopefully in the instructions somewhere.   To set 39 deg slope,  dangle a 200 cm long string with a weight in front of the dish, so it just touches at the bottom.  The gap at the top should be 113cm (= 180 sin(39) ).

Set the polarisation angle:  The starting angle is horizontal receive.  Rotate the feed till the broad faces of the LNB waveguide are facing either side.  This is the nominal horizontal polarisation starting angle.  Now, while facing the satellite, turn the feed 33 deg anti-clockwise to the final, adjusted polarisation angle.

Finding the satellite:  Just swing the dish boldly in a south easterly direction and you should find the satellite on the first swing.  Then spend an hour or so peaking up by turning the nuts in 1/6th of a turn increments.  This is important as the transmit beam is narrower than the recieve beam.  Peak up the azimuth first.

Best regards, Eric.
[ elev angle calc amended 2 June 06 ]
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« Last Edit: Jun 2nd, 2006 at 4:26pm by Eric Johnston »  
 
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Reply #2 - May 30th, 2006 at 12:53pm  
hi

Thanks eric,i got the satellite already but iam not getting high SNR.the signal is not going above 28 %.i adjusted lnb but it went upto 35% once and again went down to 28% ,i tried moving lnb both sides and swinging dish left and right ,and up and down but no change ,the signal drops to zero ..but all tv channels r clear and even sky grabber is working fine ,iam getting files and there is data reception but 28 % is very low .The connection iam going to buy is from spain(www.satconxion.com) 16 MB speed..the isp told us to get 1.8 m for our area..still signal is 28%..any chances to get more signal out of it...

I found the satellite using satfinder software ,as predicted buy the software and coverage map..using a PC..

Thanking u
Imr
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Reply #3 - May 31st, 2006 at 2:18pm  
Your 28% to 33% may be just a power measurement and NOT signal to noise ratio.  Simply adjust for the exact peak.  On a 1.8m dish you need to turn the az and el nuts in 1/6th turn increments to get to the exact beam centre.  This requires skill and patience.   Don't worry about the absolute number reading.  It is the peaking up to the exact peak that matters.    

If you can identify two azimuth angles where the power level is 28% then set the nuts either side till these values are exactly 28% and equal, when you pull and push the dish alternately sideways against the nuts, and then carefully wind both nuts in by the same number of flats.  You will then be in the exact azimuth centre (approx 33% you say).

Elevation peaking is easier, as there is normally no backlash problem.   Adjust through the peak, counting the flats and then back of to the beam centre.  

What matters is the signal to noise ratio, the carrier to noise ratio, the Eb/No and the bit error rate.  These will alter according to the size of the dish, its pointing and the polarisation alignment.    

Final optimisisation may be done using Eb/No or bit error rate.  Wait 20 seconds between each adjustment and record the exact BER at each position.

It is difficult to adjust polarisation using satellite measurements and in your case I would suggest you don't even try.  Instead, set your polarisation angle by calculation using http://www.satsig.net/ssazelm.htm.  Adjust the angle rotation of the feed throat to 1 deg accuracy.  If there is no scale, wrap a strip of paper to determine the circumference.  Rotation distance required = circumference length x angle required/360.  If there is a scale use a magnifying glass if necessary.

Best regards, Eric.
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Reply #4 - Jun 1st, 2006 at 5:05pm  
hi

Thanks again for ur help eric,i tried all that u told me ,the signal never going more than 28 in any way but the other tv channel signal with low symbol rate is increasing upto 56%..


So i dedeided to change the dish to much bigger coz the isp telling me to have min 70% signal for quality 16 MB one way satellite internet


It a 3 m cirular dish ,how much can be increase in signal,hope i get more than 70% ...


Thanking u
Imr
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Eric Johnston
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Reply #5 - Jun 1st, 2006 at 9:21pm  
http://www.lyngsat.com/eam22.html shows all the carriers.

Presumably the good TV signals you were getting were those on "Horizontal" polarisation but in spot beam S2 aimed in your direction.   If the good TV signals you have seen were marked "Vertical" then your feed needs turning 90 deg to receive the 11481 MHz H 42150 ksps carrier.

The 3m dish will give you 4.4 dB improvement and if the previous dish was just failing to lock up the signal then the new dish will be fine.  Using a figure of 39 dBW down towards you and a 1.8m dish might have just worked but you are attempting to operate well outside the satellite beam edge of 42 dBW and it may be that the 39 dBW is too high an estimate, as the levels drop quickly with distance beyond beam edge.

Good luck with the new dish.  Remember that pointing it will require fine adjustments as the beam is so narrow.

Best regards, Eric.
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Reply #6 - Jun 2nd, 2006 at 1:42pm  
hi

Thanks eric, The TV signal frequecy is 11044 V,29800-3/4
And its max 56 % @ +33 degress (clockwise)and goes down to 28% @ 0 deg lnb position and when the tv signal was @ 40%, 11481 h frequency was @ 33% .BUt then i couldnt get 33 again.but aw i need 70% .so surely  need a large dish i decided 3 m ..

The 3m dish not yet connected but its available with me ,will be tested tommorow..

Also do i need to keep 3m dish @ high level or ground level is enough coz i got the satellite @ 5 floors above the ground with 1.8 m dish but even at that i couldn lock with 1.2 m dish .

Thanking u

Imr
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Reply #7 - Jun 2nd, 2006 at 4:22pm  
For AM22 at 53 deg east, your polarisation angles should be -33 deg anticlockwise or +57 clockwise, while facing the satellite.

The TV carrier you found was Vertical polarisation.  To peak the polarisation is difficult since the peak is very broad.  If you reduce the signal either side (you say the signal went down to 22% at 0 deg. How far do you have to go the other way to also get down to 22% ?)  Halve the angle between the two equally degraded signals.  The middle of the angle is the accurate Vertical polarisation angle and should be -33 deg anticlockwise or +57 clockwise, while facing the satellite.

Horizontal, the required angle for the wanted low level internet carrier, is then with the feed turned 90 deg from the optimum angle found above for the Vertical TV carrier.

There is uncertainty if a 1.8m dish will be big enough as you are well outside the nominal 42 dBW beam edge.  If the signal is really 39 dBW towards you it might just work, with about 9 dB C/N ratio.  I would have hoped to see at least intermittent lock and high bit error rates.  The bigger dish will improve your chance.  

Regarding your data receiver, is it designed to receive carriers with as high a symbol rate as 42150 ksps ?  Also, check if the symbol rate should be 42150 or 41250.   This typo discrepancy may be the problem - what is actually in the receiver config ?.

Best regards, Eric.
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« Last Edit: Jun 2nd, 2006 at 6:41pm by Eric Johnston »  
 
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Reply #8 - Jun 3rd, 2006 at 10:55am  
hi  

thanks eric,

Today we just checked the dish,its too huge i think it is 5m with rusted bolts ,we couldnt do anything about that dish,we couldnt even move it in any way..lol.

But we decided to buy 2.4 m dish ,coz u see fixed beam
signal is 39 db(i suppose) in our area according to
http://www.satconxion.es/eng/products-services-satellite-one-way-europe-smartban...

And i saw spot beam is more in vale it seems.

And it was a typing mistake in here abt the symbol rate

its 41250 not 42510

And one more thing for internet is is compulsary to have a parabolic dish,coz the 1.8 m is a circular dish and 2.4m which we will be getting is also a circular one ..


parabolic and solid dish is available only upto 1.2 m in my city jeddah.

as u said the BEC was very high at some position were the signal was 28% and at some position it was low and at some position it was "0" as found by skygrabber (offline internet downloader)

the receiver iam using is a pci card (technisat skystar 2)

and software for locking satellite is satfinder(www.fastsatfinder.com) ..

even i used a humax receiver  with tv

Soon i will write the results of 2.4 signal level

Thanking u
Imr


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« Last Edit: Jun 3rd, 2006 at 1:07pm by N/A »  
 
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Reply #9 - Jun 3rd, 2006 at 2:48pm  
The technisat skystar 2 receiver card is only specified up to 29 Msps.   see http://www.technisat.com/datasheets/en/SkyStar2pci.pdf ;  What did satconnection recommend as a receiver ?

All satellite dishes have a parabolic shape.

Some dishes are axisymmetric, circular with the feed in the centre supported by several equal length struts.

Some dished are offset and have the feed at the side of the beam, typically supported by a main strut with possibly a further two minor struts.   The outline shape of offset dishes varies.  Oval, elliptical, diamond and jagged outlines are possible.

With any dish at Ku band the surface shape is critical.  Most (but not all) dishes are intended to have flat rims and if you stretch fishing lines up/down and across, the lines should just touch.   The maximum gap should be about 3mm for 10 GHz receive-only operation or 1 mm for 14 GHz transmit operation.   If you have larger errors you might as well have used a much smaller but accurate profile dish.

Best regards, Eric.
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Reply #10 - Jun 4th, 2006 at 4:32pm  
hi

Thanks eric ..Great analysis!! u r right The skystar 2 card supports max 29 MSPS ,and may be thus signal wont go beyond 28% due to very high symbol rate (41250 Ksps)

I checked with tv receiver humax ace II ,the signal was 50 %! a huge improvement ! and with another receiver uec Dsd supporting 45MSPS but the signal was 37% But still the signal in pc is 28 % ..due to card may be but i got 36 evenin card but dint stay for long .went to 30% then 28%


what u say !So i decided to buy 2.4 m dish + a good pci card supporting 45 MSPS max


The card is twinhan sat ci
http://www.visionplus.us/visiondtv-sat.htm
http://www.visionplus.us/visiondtv-sat-ci.htm

Will i get good siganl in these cards coz they have symbol rate 2-45MSPS

And whatcard u recommed ,coz the company  i will get email after 1 or two days (sat and sun holiday)

The company specifically mentioned for 16 MB connection pci card is required and it wont work on usb tuners may be coz of transfer limitations in usb...


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Reply #11 - Jun 4th, 2006 at 7:59pm  
Your proposed card will be able to receive the 41250 symbol rate you are seeking.  It should lock onto the carrier, adapt to the 3/4 rate FEC and start showing a bit error rate to indicate the receive quality.

However the card is primarily intended for use for satellite TV.   Its suitablilty to receive internet data will depend on the software that comes with the card and also any provided by SatConneection.

SatConnexions service provider should be able to tell you if a particualr card and the associated software is suitable for receving their signal and extracting internet traffic intended for you.    I cannot confirm this myself.

Regarding your signal measurements.  The % value is probably just a power measurement (not a signal to noise quality ratio).  Use for the purpose of peaking up the beam.

The BER is signal quality and what matters ultimately and is useful both for peaking uop the beam and the polarisation angle.

The variations you are seeing are worrying.  Do you have a bad connection somewhere?  The centre pin of the F type should stick out 2mm.   Is you mount and dish pointing rock steady ?   A 1.8m dish or larger requires a hard fixed mount and 1/3rd or 1/6th turns of the adjustment nuts to peak up successfully.  The larger the dish the finer the adjustments required.

Best regards, Eric.
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Reply #12 - Jun 7th, 2006 at 4:11pm  
hi

thanks eric

I installed 2.4m dish ,i locked the satellite (11481,h,41250),
Check the results

Tvreceiver humax (supporting max 31 MSPS)

signal Q:26%
signallevel:70%

Tvreceiver topfield(supporting max 31 MSPS)
signal Q:26%
Signal level:70%

PCicard technisat sky star 2 pc (supporting max29MSPS)

signal q:28%
signal Level:??

tvreceiver UEC(supportingmax 45 MSPS)

signal q:60%
signal level:80%

In humax receiver
Tv channel signal level (11044,v,29800) 100%
signal quality:86%


So i thought of changing my pci card to (twinhan sat ci)


Specification
  Tuner • Input terminal: F-type 75 Ohm
• Receiving Frequency: 950 ~ 2150 MHz Tuning Range
• Input Level: -65~25 dbm
QPSK & FEC • Symbol Rate: 2~45 Msps
• FEC: 1/2, 2/3, 3/4, 5/6, 7/8 and Auto
LNB & Switch control  • LNB Supply Voltage: 13 or 18V
• DiSEqC: 1.2
• Support Data Burst & Tone Burst
• Antenna and LNB Control: 22KHz Tone
• Max. LNB Supply Current: 400MA with Short Circuit Protection
PCI interface • Bus: PCI 2.2 Compliant
• Host Bus Burst Rate: 132MB/s
• Host Bus Width: 32 bit
De-multiplexing • Engine: Software
• Streams Capture: PES and TS
A/V Format • Video Format: MPEG-II Main Profile& Main Level
• Audio Format: MPEG-II Audio Layer I & II


So  iam assuming thiscard willshow60 % signal quality since it supports 45MSPS

The stand is not rock solid yet  to be cemented coz the  air is shaking it .

Thanking u

Imr
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Reply #13 - Jul 29th, 2006 at 11:00am  
imr

what's all this about? I meen why Am22?

is it better than Eutelsat W3A 7.0 East ?
that can be received with 1.2 m dish with a 100% quality and 70% signal.

unless your sat internet  is free, I think I need to know more about it ( if you don't mind ) :)
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Reply #14 - Jul 30th, 2006 at 12:12am  
He was trying to receive the one-way satellite internet service provided by SkyDSL on AM22 satellite at 11481 MHz H 41250 sps 3/4

There is an alternative, Spacegate at 10974 MHz V 29207 sps 7/8.   

I don't know prices but you can find more info on their websites at:
http://www.teles-skydsl.co.uk/
http://www.spacegate.com.ua/en/index.html

Best regards, Eric.
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Reply #15 - Jul 30th, 2006 at 7:40pm  
I am trying to set up an internet connection via SeSat2 53 deg East and I assume it is the same satellite as express Am22. Can you please help me on aligning the dish? I reside in Greece and the coordinates are: Latitude = 37,8, Longitude = 24,98380. I found out that the azimuth relative to magnetic north is 134.24 deg and the elevation should be 36.7 deg. Although I suppose the calculations are correct I cannot get any signal at all, during the last 2 afternoons (that is about 5 hours). I even moved my PC on the roof but no luck! I use a Technisat skystar 2 pci card. can you please help me?
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« Last Edit: Jul 31st, 2006 at 11:40am by Admin1 »  
 
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Reply #16 - Jul 31st, 2006 at 11:33am  
The pointing directions look about right, although my calculation gives beam elevation = 37.3 degrees.  What is the name of your location/island ?

Set the elevation scale very carefully, using a magnifying glass if necessary.  Then swing the dish boldly around the approximate azimuth angle.  You should find the satellite first time.

Do set the polarisation correctly.  While facing the satellite rotate the feed/LNB 31 deg anticlockwise from either the vertical or horizontal starting position, as specified, for the carrier you want.

If you are not finding the carrier, check the LNB local oscillator frequency in use (e.g 9.75, 10, 10.6, 11.3 GHz) is set correctly.

Also try increasing or decreasing the elevation angle in 1 deg steps, and swinging the dish again.

You will definitely need your PC or some other signal measuring device next to the antenna to detect the satellite and to peak up.  The accuracy of pointing required is very high.  

Best regards, Eric.
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Reply #17 - Jul 31st, 2006 at 12:28pm  
Eric thank you for your reply.
I reside in Porto Rafti, which is about 30 km East of the center of Athens.
I will try again using the elevation angle you mentioned. I have a question though about the elevation angle. When the dish has an offset angle one has to subtract it, so in my case the elevation angle is 37deg minus offset angle? and how canI calculate the offset angle?
Another point I didn't understand is the "carrier", and "the LNB local oscillator frequency in use". How do I put those issues into the search for the satellite?
Best regards, Kostas
P.S. Sorry about the so many questions but I haven't done this before and I am trying to learn things from point zero. Thanks again!
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« Last Edit: Jul 31st, 2006 at 4:45pm by Admin1 »  
 
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Reply #18 - Jul 31st, 2006 at 4:43pm  
Check your location lat and long again using http://www.satsig.net/maps/lat-long-finder.htm   I can't read the Greek name for Porto Rafti but I am sure you will be able to work out where you are.  You may be able to see your house.  

Elevation angle 36.6 deg perhaps ?  Set it on the scale.

Using Technisat Skystar 2 pci card you will need to input the wanted carrier frequency on the set upscreen, like one of:

Horizon 12708 MHz, H=Horizontal, 26665 symbols/sec FEC=8/9
Skylogic 12716 V 27500 2/3
PlanetSky 12602 H 4285 3/4  iDirect ?
SkyDSL 11481 H 41250 3/4   one way satellite internet service
Spacegate 10974 V 29207 7/8   one way satellite internet service

Use whatever information is provided by your service provider.  It may be one of the above.

The frequency, e.g. 12708 GHz is the downlink from the satellite.

The LNB converts to a lower frequency in the cable.  The conversion frequency is the local oscillator in the LNB.  If you have a Universal TV type LNB it probably has two alternative oscillators, 9.75 and 10.6 GHz selected by using a 22kHz tone sent up the cable for the high frequency option.  So, for example in the  Technisat Skystar setup select 22KHz tone ON.   This will make the LO go to the higher frequency of 10.6 GHz.

If you then input a chosen carrier at 12708 the card will calcuate the correct frequency in the cable 12708 - 10600 = 2108 MHz.

The card also needs to know the symbol rate e.g. 26665
The FEC rate, like 8/9 may be discovered automatically. Select Auto if you don't know.

If you have a universal satellite TV LNB and mount it upright on the arm, vertical polarisation will be with the voltage low like 13 volts and Horizontal with +19 volts.  You will still need to adjust it about 31 deg anticlockwise from the upright starting position.

Best regards, Eric.
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Reply #19 - Jul 31st, 2006 at 4:58pm  
Hello again.
Do I need to subtract  the dish offset angle from the elevation angle as it is explained in your site?
The latitude and longitude are the same as in your calculations.
Best regards, Kostas.
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Reply #20 - Jul 31st, 2006 at 11:27pm  
If your dish has an elevation angle scale, use it to set the elevation angle to 36.6 deg.  The manufacturer will have already taken the dish offset angle into account, so use 36.6 deg.

If there is no scale, set the front face of the dish exactly upright.  The beam elevation angle will then be the same as the offset angle, which you must obtain from the manufacturers data.   Your wanted beam elevation angle is 36.6 deg and since this is greater than the offset angle you will need to tilt the top of the dish backwards by a further amount = 36.6 - offset angle.

Offset angles, e.g 22 deg, vary from one dish design to another.  That is why offset dishes normally have a scale.

Best regards, Eric.
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« Last Edit: Aug 2nd, 2006 at 11:02am by Eric Johnston »  
 
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Reply #21 - Aug 2nd, 2006 at 8:20am  
Eric, thank you for your reply.
I am about to buy a satellite signal finder for 10 euros and then climb up on the roof to try again. The dish has no scale so I will use your suggestion to estimate the elevation angle. I hope this time I will succeed.
Best regards.
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Reply #22 - Aug 6th, 2006 at 4:05pm  
I knew that I was doing something wrong.
But it turned out to be the ramification switch which was not working, so there never was a connection between the LNB and the PCI card!
The local mechanic found it and I payed 50 euros for his work!
Well anyway everything is working normally now and I am able to download 11Mb in less than 3 minutes!
Thank you for the support again.
Best regards.
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