Astra 2D in Sicily?..not yet.... :( but Im not giving up!!!

[Likvid]

OK, if we just can get the C/N values at your location we can tell how far away you are from even receiving any signal.

These C/N values are needed to get a signal lock at these FEC:

FEC C/N

1/2 4.1dB

2/3 5.9dB

3/4 6.9dB

5/6 7.9dB

7/8 8.5dB


You can push the C/N limits a bit down further if you have a really sensitive receiver, maybe 0.5-0.8dB down or so.....

After looking at Lyngsat i can see that BBC on 2D uses FEC of 5/6 which means you need a pretty high C/N to even get a signal lock, eg 7.9dB

Just get the C/N for your site location, it's much easier than to speculate all the time.

Please take a note and maximize the dish on Hotbird or something that you know have great coverage at your location and then measure the C/N, that way we can know how your dish setup is performing.

Likvid,
Next time we try again I will get some pictures of the log from the Spectrum analyzer so we can see the signal levels in C/N( what does it mean C/N just to be sure?) and I will tell you what Spectrum analyzer we use.

I think this is all for now
Ciao
Tony

 

[dave branson]

Tony
The Satlex site is for offset dishes,for instance,when i plug in my lat/long for
Florence it gives the same skew angle -16.4,(11-0 oclock)where as as my LNB is skewed at about 30deg to the right ie about 5-00 o,clock.

 

[fawad]

dear tony

C/N mean carrier to noise ratio, to get idea of RF signal strength on dish, LIKVID very good, you have to isolate the fault step by step before any further investment.



Your dish size look ok, you check a lot for dish parabola…its depth etc, as u said its results are like 1.5 m, now your LNB may be partially damage, i.e. its pickup probe misaligned or..

Fix it on other working setup & compare the reception, especially on week channel, then check receiver in same way, then try new one.

working on a stable air temperature time can also consider for fading.

To get maximum signal first try to tune satellite beacon signal, this is more stable & specially used for such jobs.



LNB feedhorn mounting for ZARBA is easy then your so just careful adjustment….

 

[ynot62]

Likvid,
in your experience what should be the right Az/El and skew for my location?
Just to remind you I live in Taormina, on the east coast of Sicily, 50 kms north of Catania; my town is on 200 mts on sea level.
I bought a new Invacom quad, so I can have another option.
My decoders are Panasonic 30, Panasonic 50 and Nokia 9800; when I checked on the Nokia 9800, I saw the signal quality jumping up to yellow and then disappeared suddenly, this has happened many many times.

Thanks for now

Tony

OK, if we just can get the C/N values at your location we can tell how far away you are from even receiving any signal.

These C/N values are needed to get a signal lock at these FEC:

FEC C/N

1/2 4.1dB

2/3 5.9dB

3/4 6.9dB

5/6 7.9dB

7/8 8.5dB


You can push the C/N limits a bit down further if you have a really sensitive receiver, maybe 0.5-0.8dB down or so.....

After looking at Lyngsat i can see that BBC on 2D uses FEC of 5/6 which means you need a pretty high C/N to even get a signal lock, eg 7.9dB

Just get the C/N for your site location, it's much easier than to speculate all the time.

Please take a note and maximize the dish on Hotbird or something that you know have great coverage at your location and then measure the C/N, that way we can know how your dish setup is performing.

 

[Likvid]

I don't have the satmaster software installed right now so i can't tell what the correct AZ/EL should be, you shouldn't be looking at what theoretical values you get with skew and everything, it's all down to what instrument and installer you have.

You only need to know roughly the the elevation angle, i have never bothered with Azimuth, if you know the elevation then it is just straight forward.

Have you checked dish surface accuracy? put two strings across dish and tighten them a bit, if the strings are just touching each others in the cross in the middle of the dish then the dish is ok, if there is a large gap between the strings or if if the strings is touching each other so much that they push each other down, then your dish is not aligned correctly with the petals.

Just put one string from 2:00PM to 8:00PM, then another string from 10:00PM to 4:00PM, check the strings!

Do another test, put the string from 12:00PM to 06:00PM, the other one from 3:00PM to 9:00PM, check again!

Likvid,
in your experience what should be the right Az/El and skew for my location?
Just to remind you I live in Taormina, on the east coast of Sicily, 50 kms north of Catania; my town is on 200 mts on sea level.
I bought a new Invacom quad, so I can have another option.
My decoders are Panasonic 30, Panasonic 50 and Nokia 9800; when I checked on the Nokia 9800, I saw the signal quality jumping up to yellow and then disappeared suddenly, this has happened many many times.

Thanks for now

Tony

 

[Zorba]

Another point is time of day.Over here 2D is strongest between 1-5pm (GMT+2 hours) but the others (2A 2 are at their weakest at the same time.@a 2B are stronger after 5pm.For us sky news(12.207V) and sky sports(12.110H)are the strongest channels and sky movies the weakest,so I would lock on to the weakest(sky movies 11.914H 27500 2/3) and play with dish/lnb and go for maximum,then look for the strongest frequency on 2D which,over here is 10.744V 22000 5/6(irish channels).I hope that makes sense.

 

[apogee2010]

Half question/comment: from reading back through the posts, I understand that you are using an ADL Ku-band feed with a WR75 flange connected directly to a C120 LNB. Should there not be a quarterwave transformer between the feed and the LNB?

 

[ynot62]

Hi guys,
My installer gave up today..
Is anybody, here in the forum, of the people they have been helping me lately, and I mean professional installers, avalaible to come to Sicily and fix my dish for best performance?
I know it is a weird question but I really dont know where I can find someone who knows about Fringe reception.
Thank you for now
Ciao
Tony

 

[Likvid]

Here is a nice picture of a nice feed mounted on a Patriot dish, i think it is the same 3.8m dish, could be the 4.5m, not sure really.

As you can see they don't have any spacers as you have added.

 

[ynot62]

Likvid,
Thanks for the picture.
You probably didnt follow my thread from the beginning;
when we first installed the dish we found out that the F/D was wrong; it came out 154.4 cms instead of 156.9 cms as said by Patriot.
Thats why I had to put some spacers.
I got in touch with Patriot several times but they were not able to tell me why this F/D was wrong.
I guess something was wrong on the delivery; the feed struts or the outboard feed angles but Patriot keep on telling me that everything sent is right.
What a mistery!!!
I really dont know what to do.

Ciao for now
Tony

Here is a nice picture of a nice feed mounted on a Patriot dish, i think it is the same 3.8m dish, could be the 4.5m, not sure really.

As you can see they don't have any spacers as you have added.

 

[Likvid]

Why should Patriot be wrong?

Their antennas are designed to exact measure as most antenna manufacturers do with their CAD software.

The antenna feed legs are manufactured to tight tolerances so i can't really imagine it would be their fault.

Why don't you call Patriot for an installer? as i said they have their own engineering teams flying around the world or can recommend one installer closer....

I wouldn't be surprised if you have aligned the dish to the antenna sidelobes all the time when you say it works like 1.5 meter dish.

The antenna pattern have one narrow mainlobe and one weaker sidelobe on each side of the mainlobe....

The sidelobe pattern of a dish bigger than 3 meter is like a smaller dish.

If you align a 3 meter dish to one of the high powered Eutelsat satellites you might think you are using the main lobe of the dish, but the truth is that it's one of the antenna sidelobe instead.

Has happened to me several times, that is one of the problem with a large dish in that caliber, the sidelobes are so strong and the mainlobe is so narrow...

 

[ynot62]

Ok you cant really imagine it would be Patriot's fault but then why they say F/D should be 156.9 cms but my F/D without spacers is 154,5 cms?
I sent an email to Patriot asking for an installer but till now I didnt receive any answer back.
About sidelobs and mainlobs, I agree with you; I really think that this is the mistake we did all the time, even if my installer said we always aligned the dish to the mainlob.
And one more question: should I really care about the skew or I better try to align the dish the best I can and then looking for the right skew? Do you really think that the skew is so important? Lets say: I align the dish and I get no signal, then I leave the dish on the same alignment and I look for the skew could I get the signal?
Ciao for now
Tony

Why should Patriot be wrong?

Their antennas are designed to exact measure as most antenna manufacturers do with their CAD software.

The antenna feed legs are manufactured to tight tolerances so i can't really imagine it would be their fault.

Why don't you call Patriot for an installer? as i said they have their own engineering teams flying around the world or can recommend one installer closer....

I wouldn't be surprised if you have aligned the dish to the antenna sidelobes all the time when you say it works like 1.5 meter dish.

The antenna pattern have one narrow mainlobe and one weaker sidelobe on each side of the mainlobe....

The sidelobe pattern of a dish bigger than 3 meter is like a smaller dish.

If you align a 3 meter dish to one of the high powered Eutelsat satellites you might think you are using the main lobe of the dish, but the truth is that it's one of the antenna sidelobe instead.

Has happened to me several times, that is one of the problem with a large dish in that caliber, the sidelobes are so strong and the mainlobe is so narrow...

 

[Likvid]

How do you know that you calculated the correct F/D?

There are many more factors to include and take notice to than measure the depth and diameter of the dish......

Have you had an spectrum analyzer and looked that your F/D is correct? if not then you wouldn't know exactly what the correct F/D is.

Exact F/D and focus of the feed is measured with the analyzer at site.

As i have already said you must align the dish to a high-powered satellite that has coverage where you live, you are trying to do the install from ground by adjusting it to Astra 2D, that is the wrong way to adjust the dish as you are out of footprint and you will never know how your dish should perform.

Get an analyzer and peak the dish to one of the hotbirds, adjust the feed to what Patriot gave you and work from that and at the same time observing the analyzer.

When you have peaked the dish and feed and documented the results you can peak the dish to Astra 2D.

You need to set exact correct skew with the analyzer, you need an analyzer where you can see the patterns so you can truncate the opposite polarization.


As we don't know what your dish is like it can be installed incorrectly as well, the panels maybe isn't lined up exactly.

Have you checked the dish so it's correct and not warped with the string method?

Anyway, you will probably need an professional installer in the end.

I can recommend you one in Italy that only do large based installations for Teleports and such, but it will probably cost you pretty much, but you can talk to them and see how much they want.

PM me about contact details.

Ok you cant really imagine it would be Patriot's fault but then why they say F/D should be 156.9 cms but my F/D without spacers is 154,5 cms?
I sent an email to Patriot asking for an installer but till now I didnt receive any answer back.
About sidelobs and mainlobs, I agree with you; I really think that this is the mistake we did all the time, even if my installer said we always aligned the dish to the mainlob.
And one more question: should I really care about the skew or I better try to align the dish the best I can and then looking for the right skew? Do you really think that the skew is so important? Lets say: I align the dish and I get no signal, then I leave the dish on the same alignment and I look for the skew could I get the signal?
Ciao for now
Tony

 

[Likvid]

I have helped Tony now with a contact in Italy that are professionals in installing VERY large based earth stations, up to 15 meter dishes so they know their stuff and have appropiate equipment.

They will come to Sicily and look at his dish and probably they will be able to make it perform as it should, if they can't do it, no one can make it work.

Will be very interesting in watching this thread and what they will say about your dish.

 

[iceman]

Will be very interesting in watching this thread and what they will say about your dish.

Somehow i have a feeling that i wont be surprised much of the outcome.
Some silly mistake could have easily slipped by Tony's installer.I do not blame him if he had no past experience on large dish installations.Lets face it,a big majority of the dishes installed in Europe are not larger than 100cm.

iceman

 

[rolfw]

You're right there, although we have a few people on this forum with large dish experience, the vast amount of satellite installers (me included), seldom deal with dishes above 1 or 1.2m in diametre.

 

[barney]

I have helped Tony now with a contact in Italy that are professionals in installing VERY large based earth stations, up to 15 meter dishes so they know their stuff and have appropiate equipment.

They will come to Sicily and look at his dish and probably they will be able to make it perform as it should, if they can't do it, no one can make it work.

Will be very interesting in watching this thread and what they will say about your dish.

Me too Likvid, ;)
than you very much for your help.
I'm waiting his reply
Barney

 

[powel000]

Im shocked, a 3.8 meter Patriot signal in Sicily, probably I will need a 10 meter in Amman-Jordan to even dream of recieving Astra. Is Astra the worst or what

 

[dave branson]

Me too,I am really looking forward to this,hope we can get lots of tips and advice.
Great Likvid.

 

[Old Satellite]

It is very true there are a few large satellite dishes in Europe if you not include teleport systems etc.

Although when the " Hobby started" many were at least 2.0mtr just to recieve a few intelsats (cir 1990).

At least now with the help of the forum Tony can recieve the support of a visit to check and set up his Patriot 3.8.

I still believe correctly set up that he should be able to recieve Astra 2D.

looking forward to the news after the visit.

Best regards to all


Old Satellite