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Help with Tooway install

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Oct 10^th, 2009 at 4:35pm

Hi
Encouraged by Cambrian's success with his Tooway self-install, I took the opportunity to purchase the Tooway hardware from a previous Tariam customer.
The dish, TRIA, Modem & miles of coax cable arrived from the vendor and I set about installing it on the front of the house.
I then signed up for the basic account with Bentley Walker. connected it all up but alas no satellite lock. I telephoned BW and spoke to a technician who informed me that I needed a better C/N ratio (I only got about 9.3db). At this point I decided to put the dish on a chimney mast well clear of any obstacles . I borrowed a 'cherry picker' from a friend and duly sited and aligned the dish about 500mm above an Astra 2D dish. Using a Promax Prolink-2 spectrum analyzer, these are the results at the dish.

C/N Referenced: 10.4 dB

Video Carrier
Frequency: 1377.75 MHz
Level: 73.9 dBuV

Noise
Frequency: 1443.5 MHz
Power: 63.5 dBuV
Channel BW: 30.0 MHz

These levels are attenuated aprox 6dBuV by the coax down lead to the modem location.

The modem acquires a signal but alas still no lock.

Extract of the event log:-
THU JAN 01 01:03:49 1970 DS Scan: 1375.636353 [MHz]
THU JAN 01 01:03:42 1970 DS Scan: 1380.000000 [MHz]
THU JAN 01 01:03:40 1970 DS NAPA: Success
THU JAN 01 01:03:39 1970 DS Acquire: 1375.574951 [MHz], 30.00 [Msps], 10.00 [dB], MR
THU JAN 01 01:03:33 1970 DS Scan: 1375.574951 [MHz]
THU JAN 01 01:03:26 1970 DS Scan: 1370.000000 [MHz]
THU JAN 01 01:03:06 1970 US Scan: 2144.399902 [MHz], Channel 5
THU JAN 01 01:02:11 1970 US Scan: 2140.800049 [MHz], Channel 8
THU JAN 01 01:01:39 1970 US Scan: 2148.400146 [MHz], Channel 3
THU JAN 01 01:01:37 1970 DS NAPA: Success
THU JAN 01 01:01:36 1970 DS Acquire: 1375.625488 [MHz], 30.00 [Msps], 11.00 [dB], MR
THU JAN 01 01:01:30 1970 DS Scan: 1375.625488 [MHz]
THU JAN 01 01:01:23 1970 DS Scan: 1360.000000 [MHz]
THU JAN 01 01:01:18 1970 DS Scan: 1350.000000 [MHz]
THU JAN 01 01:01:13 1970 DS Scan: 1340.000000 [MHz]
THU JAN 01 01:01:08 1970 DS Scan: 1330.000000 [MHz]

Do I need to hunt around for a different location or is there a possible fault in the TRIA or modem.

Any advise will be most appreciated.
Regards
Wil

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Eric Johnston

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Reply #1 - Oct 10^th, 2009 at 6:06pm

I recently made a Tooway dish pointing calculator that gives results for the polarisation angle that match the scale on the large circular boss behind the dish. It goes either way from 90 deg, when the subreflector/feed support arm starts off at the bottom. If the polarisation is distinctly wrong then adjusting it will improve matters.

Another possible reason for poor performance might be assembly error, distortion of the dish or water in the feed horn. �Is there any chance of dimensional errors in the positioning of the feed/TRIA ? � Has the subreflector/dish been bent at all ? Does it all fit togehter perfectly. �The accuracy of everything to 1mm is needed for 19 GHz receive.

If you are in north west Scotland you will need the larger size dish, see Tooway satellite service coverage maps

Do Bentley Walker have the serial number of your modem ?

Provided the lower edge of the dish has a clear view of the satellite, moving the dish to another location will have no effect.

Best regards, Eric.

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Reply #2 - Oct 10^th, 2009 at 10:11pm

I am located in North Wales at approx latitude = 52.9, longitude = -4.4
My initial settings were thus
Dish elevation= 27.4
Azimuth= 163.5 M
Polarisation= -12.7+3.5=-9.2
There seems to have been some debate about the +3.5 degrees added to the skew; I went with it because of �Figure 8 : Polarisation Angle Chart for the 13�East Orbital� in Eutelsat�s document �Annex A The Hot Bird� Satellite� http://www.eutelsat.com/satellites/pdf/tvservices/annex_a_HOTBIRD_sat_sys.pdf
The assembly seemed visually ok when I installed it. Unfortunately I do not have access to the dish until early next week to double check the physical condition of the dish & TRIA.
In the meantime I have uploaded a photo of the spectrum analyser

taken at the indoor end of the 25m coax which is quite similar to the one published by El Molino :-
http://www.europe-satellite.com/EMS/pdf_files/sat_info/hotbird6_sa_info01.pdf

BW only required the MAC address of the modem, which they received when I subscribed to the basic package.
Many thanks for all your help and advice.
Wil

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« Last Edit: Oct 11^th, 2009 at 10:40am by Admin1 »

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Reply #3 - Oct 11^th, 2009 at 10:16am

Quote:

Do I need to hunt around for a different location or is there a possible fault in the TRIA or modem.

Any advice will be most appreciated.

Coax RG6 cable ? +- 25m ?

Your skew setting looks a bit strange, not sure it is right.

It can take some time before modem locks.

The skew info from satsig is a good point to start, it is close to it but you have to fine-tune at location.

e.g. Fornalux, Mallorca, Illes Balears, Spain (09-10-2009)

Satsig:
Dish elevation= 42.8
Azimuth= 165.4 (magnetic compass)
Polarisation= -12.1 anti-clockwise, Blue scale skew= 102.1

Final Settings:
Dish elevation=44.8
Azimutch=?
Scew=108

I have done Tooway installs in the South-West of Portugal outside the footprint, 68 cm dish, good signal and no problems.

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« Last Edit: Oct 12^th, 2009 at 9:00am by N/A »

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Reply #4 - Oct 11^th, 2009 at 11:51am

Hi Wil,

I am some way south of you but my settings are:-
elevation 31.5deg. (I believe the scale is not quite right on the dish). Skew is 80.7 deg and azimuth set by compass at around 163/164 deg.

It is VERY misty, lots of water droplets in the air, and it is raining hard also but my system is working fairly well this morning.

Hope this helps.

Best regards,

Tony

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Reply #5 - Oct 12^th, 2009 at 1:14pm

Thanks all for all this assistance.
The coax is Webro WF100 (attenuation of 23.4dB/100m). On checking, the length is 29.5m for both Rx & Tx
I have left the modem connected overnight without a lock.
Since rotating the assembly +- 5� had no apparent effect on signal strength I set the skew with a digital protractor/inclinometer. At my location satsig calculated this as -12.7�, I then added the +3.5� offset �giving a skew of -9.2�, this corresponded to 100� on my dish's scale (mast not quite plumb) . As noted by Tony during his install there has been some debate about this +3.5� and since it worked for him I settled for this same offset (this is also borne out by Eutelsat's polarization graph for Hotbird 6).
It now seems that polarization is more complicated than this. I notice from europe-satellite's install in Formalux that the actual skew required was -18� whilst Tony�s in Mid Wales is +9.3
It seems, from the ViaSat modem�s event log, that a downstream connection is established.
� �THU JAN 01 01:01:37 1970 DS NAPA: Success
� �THU JAN 01 01:01:36 1970 DS Acquire: 1375.625488 [MHz], 30.00 [Msps], 11.00 [dB], MR
But after several attempts, upstream is not completing
� �THU JAN 01 01:03:26 1970 DS Scan: 1370.000000 [MHz]
� �THU JAN 01 01:03:06 1970 US Scan: 2144.399902 [MHz], Channel 5
THU JAN 01 01:02:11 1970 US Scan: 2140.800049 [MHz], Channel 8
� �THU JAN 01 01:01:39 1970 US Scan: 2148.400146 [MHz], Channel 3
This is only guesswork on my part, I assume that the 30.00[Msps] is symbol rate & 11.0dB is C/N. I do not know what MR or NAPA mean.
Further progress is now delayed as I will not have access to the dish until later in the week (cherry picker not available).
Again, many thanks for everyone�s help.
Wil

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Admin1 YaBB Administrator ★★★★★ Offline Posts: 969	Reply #6 - Oct 12^th, 2009 at 4:22pm I've spoken with Scott at Bentley Walker about your site. You need to call him on 023 9231 1118 to activate your site. Best regards, Eric.
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Reply #7 - Oct 12^th, 2009 at 4:37pm

Hi Wil,

It seems from the above post that you may have other problems but if you are able to suspend disbelief may I suggest you set your skew to 80.7 ish deg. and let us know what you find. You are quite close to me and should be able to use a similar skew setting. Although they are a couple of hundred miles SE of me, I do know that BW. were using 82 deg. in May 2008 when I set my system up.

Best regards,

Tony

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Reply #8 - Oct 12^th, 2009 at 5:19pm

Wil, Tony

Site activation:
BW indicated that the modem was from previous service provider where it had been de-registered. �A new activation configuration and process was needed, that maybe involved getting Skylogic to transfer the modem in their database and a new customer PIN being issued.

Polarisation:
If there is a carrier on the opposite polarisation then some small polarisation movement, say 10 deg, will make a noticable difference.

If there is no cross-pol carrier then you will need an error of +/- 45 deg to get a 3 dB reduction. �If you can measure the angle at these exact -3.0 dB points then you can half the angle between them.

If there is no cross-pol carrier and you have a spectrum analyser and turn the polarisation boldly approx 90 deg the wrong way you will find the narrow sharp null where the wanted carrier disappears. �It is fairly easy to identify either side of this deep null and note the centre angle. Then turn the system exactly 90 deg for the optimum angle.

Attempting to peak up the quality by small adjustments of polarisation, in the absence of a steady high power cross-pol interferer, is not practically possible.

I am anxious to verify the polarisation angle calculation on page Tooway satellite antenna pointing and maybe even resolve if the +3.5 deg offset applies to the Ka band beam as well as Ku band beams on Hotbird.

Some people seem to agree with the calculator, others get peaked up results at different angles. No idea why as the downlink beam is a single all-Europe coverage.

My understanding is that rotating the dish anticlockwise, as for sites in the UK aimed at 13 deg east orbit position, increases the scale reading from 90 (i.e. direction towards 100). �Such polarisation adjustments are negative, like -10 deg. Anticlockwise as seen facing towards the satellite. �

Best regards, Eric.

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« Last Edit: Oct 12^th, 2009 at 7:04pm by Eric Johnston »

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Reply #9 - Oct 12^th, 2009 at 7:02pm

Hi all
Many thanks Eric, I got back too late this evening to phone Scott at BW. Since my last post I have spoken with Simon at BW and emailed him the modem event log. Then Paul emailed requesting further information which I have also sent. Methinks too many cooks spoil the broth;-) However I will phone Scott tomorrow re. activation.

The cherry picker has just come back so tomorrow will have a go at finding the sharp null with my SA and let you know the results.

Tony, as you suggests, I will also give 80.7� skew a go, if all is well how long should the modem take to get a lock?

I will also check in case there were any distortions in the dish/arm during assembly.

Many thanks all
Wil

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Reply #10 - Oct 12^th, 2009 at 7:11pm

We are all trying to help you.

I think your site receive quality is fine with 11dB C/N. I've seen documents refering to sites with minimum of C/N=5 dB..

My opinion is that the skew scale should be about 100, i.e. about 10 deg anticlockwise from the start position. Anticlockwise as viewed with you behind the dish and facing towards the satellite in the sky.

Please tell us how you get on. If BW need to get Skylogic to do something don't expect instant results ! Reconfiguring a previously blocked site with a different service provider and getting it restarted is a bit more complicated than setting up a new out-of-the-box modem.

Best regards, Eric.

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Reply #11 - Oct 13^th, 2009 at 8:38pm

Hi all
I have spent the afternoon trying various skew angles. First I rotated the assembly through 90� in an attempt to find the null at the opposite polarity; unfortunately without success (I suspect that my movements are too coarse). After some discussion with Scott & Simon at BW they suggested I set the skew at 84� on the scale (as Tony pointed out, they are using 82� at they�re site Hayling Island); this also proved fruitless. They then suggested I try 86� but still no success. In all this up/down left/right I suspect I may have now pushed the dish slightly out of alignment since the modem now reports a C/N ratio of only 6dB Sad

Is it possible that the difference skew angles that Tony and europe-satellite suggested are because Spain is on a different uplink spot beam to France/UK.
Oh well, better luck tomorrow.
Best Regards
Wil

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« Last Edit: Oct 22^nd, 2009 at 12:01pm by Admin1 »

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Reply #12 - Oct 14^th, 2009 at 12:00am

Quote:

Is it possible that the difference skew angles that Tony and europe-satellite suggested are because Spain is on a different uplink spot beam to France/UK ?.

There is just one broad downlink beam for all Europe. �You are measuring the downlink signal. �All sites should have adjustment angle settings based on one method of calculation.

The satellite is dual polarisation and if Eutelsat have put similar carriers on the opposite polarisation then it will be difficult to find a null using a spectrum analyser. �You need to be bold about the dish rotation. �If you turn the dish all the way through 360 deg you should see the two different polarisation spectrums, appear and disappear alternately, at 90 deg intervals, with very broad peaks and sharp nulls when each spectrum disappears.

The Tooway antenna design is such that beam should remain aimed at the satellite as the polarisation is rotated. If the feed support arm is sagging down (loose or not rigid enough) then this will not apply.

My opinion is that your adjustment angle should be -12.7 or -9.3 deg anticlockwise, as viewed from behind the dish and facing towards the satellite in the sky, starting with the arm at the bottom centre position.

Best regards, Eric.

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« Last Edit: Oct 14^th, 2009 at 10:05am by Admin1 »

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Reply #13 - Oct 14^th, 2009 at 5:06pm

Eric
Today I took a laptop with a wireless connection to the modem up with me and rotated the dish in 1� increments, querying the modem at each move. I found that the modem�s reported C/N ratio dropped from 10dB to 9dB at 95� and 111� on the dish�s scale and duly set the angle to 103�. This matches up pretty well with your Blue scale skew of 102.7 � for my location. Mind you all this tweaking still doesn�t get the modem to lock. I am now waiting for Simon at BW to get a reply from Skylogic before I can do any more.
Many thanks & best regards
Wil

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Reply #14 - Oct 14^th, 2009 at 7:09pm

Well done.

I'll take that as one vote that this calculation page Tooway satellite antenna pointing is giving correct results.

Regarding the LED displays I would have thought that anything above 5 dB would show signs of good receive operation and 10 dB certainly so (once the modem has spent time scanning, looking fo the caririer).

The table of LED lights on some older Surfbeam modems used in Ku band was like this:

I don't know if recent modems show the same results.

If your modem is stuck in the fast blink state I guess that it is Skylogic yet to transfer the site in their hub database to the new service provider. I think you may need a pin number at some stage.

Best regards, Eric.

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Reply #15 - Oct 21^st, 2009 at 10:56am

Success at last.
As pointed out by Eric earlier 'If BW need to get Skylogic to do something don't expect instant results !'.
It turned out that I had a faulty TRIA. On Monday BW were advised by Skylogic to replace the TRIA which they promptly sent to me and arrived yesterday morning. I installed it in the evening and the modem locked in a few minutes. I telephoned Scott at BW this morning and my site activated with no problems.
My final settings were bang in line with Eric's Tooway dish aiming calculator.
Many thanks to all who helped.
Best regards
Wil