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

Likvid · 28-09-2005

I have asked the Aussie guy with Patriot experience to come and write in this thread.

***dave branson*** · 28-09-2005

Originally Posted by Likvid

I have asked the Aussie guy with Patriot experience to come and write in this thread.

That will be very interesting.

**ynot62** · 28-09-2005

I really dont know what else I can do,
We tried everything.
It seems that my dish settings have all the strangest misteries..

.
For instance, when the technician stepped into the centre of the dish, only on certain point of the petals we could get the signal, he just walked very slowly to find the only point that with a pressure of the foot could give us the signal.
Because of that, we thought the dish was distorted but then I put 2 wires crossing eachother and the dish seems ok,
We calculated the F/D with the famous formula and it is perfect.
At this stage the only thing we still didnt do is to change the feedhorn.
I am getting very frustrated now.
I hope that the aussie guys can help me out.
Ciao for now
Tony

Originally Posted by zorba

Well,I think that when he stepped in to the centre of the dish he increased the distance from dish to feedhorn,which might mean that your focal distance is too short.I know its not easy for you to adjust your lnb but tell your technician if he can supply an alternative feedhorn bracket that allows you to slide it up and down a bit and check the signal on his meter at the same time.

**simonskyman** · 28-09-2005

Sometimes two strings are not enough,you might miss a twist in the dish in between ,for example,12 oclock and 3 oclock.thats why you have to have a visual check looking from the side and also from the bottom towards the top.

***iceman*** · 29-09-2005

Originally Posted by simonskyman

Sometimes two strings are not enough,.

Agreed...I always use four strings....

trash · 29-09-2005

Hi guys, likvid asked me to come and have a look at this thread.
Patriots.... you have my sympathy, they can be rather difficult antennas to work with. I had a quick skim back through some of the posts.

A picture says a thousand words. A picture of the antenna from front, side and back would be a good start. Looks like most people have suggested the same things I would suggest checking myself. I find 2 strings are enough, but changing their positions has the same effect as more string lines. They should just be touching, there should not be a large gap between them or they should not be pulling against each other.

The pictures will help, and if there is something obvious, I think we'll all spot the problem. Measure the diameter accurately and the distance from the center of the dish to the feed horn. (post both of these values). If it's casigrain, some pictures of the feed horn and waveguides would be helpful.

Patriot generally didn't think through some of their designs, and things like the elevation screws are very coarse. A single turn of a nut can move a dish considerabley. Their azimuth screws aren't much worse than other antennas.

A bigger dish of course requires more precission, in the case of patriots, it becomes extreemly annoying when you don't have good control over where the antenna is pointing.

The method I have used succesfully for patriots in the past is:

1> Set the azimuth first.
If you have another antenna, you could use it, else you just want to be as precise as possible with your azimuth elements. Use your compass or dish and pick an object as far away as possible as a reference. a tree or TV antenna on a house or anything ... I sometimes use clouds if they are not moving quickly.

From the king post, the lowest part of the dish represents the azimuth. Hanging a plum bob from it helps with precission. When you think you have got the azimuth correct. then try elevation.

2> Elevation.
Set the elevation lower than where you expect to find the satellite and slowly raise it by turning the nut. When you are sure you are too high, then lower it back to where you started. A marking pen helps you keep within the window.
A slight adjustment of the azimuth and you try again.

Try not to make any sudden movements, keep them all as small as possible, it's these large movements that cause problems because they move the antenna in almost unpredictable ways.

Try and get the polarisation correct to start with, but don't be too fussed about it.

I'm not sure if you have access to something like a spectrum analyser or something like a chart recorder connected to a signal strength meter.
You can use this slow response (narrow bandwidth) signal strength to see accurately what is going on in the sky as you pan.

You must remember the #1 rule. The background radiation of the universe (the big bang) is uniform everywhere you look in the sky. The only place that this noise is higher is where the sun, moon, radiostars and satellites are.

You can practise by pointing your dish at the sun or the moon when it close to where you want to point your dish at the satellite. Using your signal meter you should be able to easily peak up on the sun or moon, and then watch it drift out as the earth rotates.

This is an example of what the signal meter will do as the sun or moon passes through the beam of the dish. It's a "pattern cut"
http://www.vetrun.com/forums/showthr...ight=side+lobe

You can see the main lobe in the center with the side lobes.

If you get this kind of response as the sun/moon pass through, then you know all is good. If the pattern isn't symetrical, then you may find that your feed horn is not alligned and/or focused correctly.

I don't log into this forum often, but I will try and read this thread more often. If you don't get a response from me.... likvid or somebody else and ping me and wake me up :-)

***dave branson*** · 29-09-2005

Very interesting,i feel sorry for Tony,buying an expensive Patriot dish which does not work at the moment.

***Old Satellite*** · 01-10-2005

I would like to add from personnel experience that Patriot dishes are of good quality for the purchase cost.- there are better (and more expensive and certainly far worst.

It is and always will be time consuming in the installation in "any" large dish, the petals normally take about a day to align correctly for best performance.

The 3.8 mtr should be capible of the task at the location, also please do not forget as Tony has identified it is difficult to install the dish of this size if you have not done so before.

Many readers will have seen/ and read from my own Patriot the acheivements on that of my own system.

Tony Please could you Pm me your email address and I will send you an overview of setting up your dish - it might help you further, and gain 2D
Kind Reagrds

Ols satellite

trash · 03-10-2005

Any photo's yet ?
A picture is the next best thing to actually being there.

You might find that is is something so simple you never considered it.
I had a job where they installed a dish in a very remote location. I gave instructions that I was sure were going to work. To test the theory I had a hand picked village idiot follow the instructions from scratch and it wasn't long before he had the satellite.
But the remote location, the tech's couldn't find the satellite or any satellite.
I smelt a rat, so I was eventually persuaded to do the trip.
After a couple of minutes of panning the sky and finding nothing but the tiniest lump in the background radiation, I decided to replace the LNC. It looked like it had some massive attenuation (maybe a broken FET). Upon pulling it off the feed support, I discovered the problem.
The mounting plate was solid metal and they had just bolted the feed horn on one side and the LNC on the other with a wall of metal blocking the waveguide. I drill out a hole and put it all back together (while trying not to laugh). The tiny lump that I was seeing was actually the satellite despite the waveguide being blocked.

You can see the importance of actually having a variation in background noise as you move the antenna across the sky. (or the sky moves across it).

**ynot62** · 05-10-2005

Hi Trash,
here are the photos you requested.
I hope they can help us to sort out the problem I have.
Thanks for your help.
Ciao
Tony

Originally Posted by trash

Any photo's yet ?
A picture is the next best thing to actually being there.

You might find that is is something so simple you never considered it.
I had a job where they installed a dish in a very remote location. I gave instructions that I was sure were going to work. To test the theory I had a hand picked village idiot follow the instructions from scratch and it wasn't long before he had the satellite.
But the remote location, the tech's couldn't find the satellite or any satellite.
I smelt a rat, so I was eventually persuaded to do the trip.
After a couple of minutes of panning the sky and finding nothing but the tiniest lump in the background radiation, I decided to replace the LNC. It looked like it had some massive attenuation (maybe a broken FET). Upon pulling it off the feed support, I discovered the problem.
The mounting plate was solid metal and they had just bolted the feed horn on one side and the LNC on the other with a wall of metal blocking the waveguide. I drill out a hole and put it all back together (while trying not to laugh). The tiny lump that I was seeing was actually the satellite despite the waveguide being blocked.

You can see the importance of actually having a variation in background noise as you move the antenna across the sky. (or the sky moves across it).

**ynot62** · 05-10-2005

Hi Trash,
here are more photos about my dish.
Thanks
Tony

Originally Posted by ynot62

Hi Trash,
here are the photos you requested.
I hope they can help us to sort out the problem I have.
Thanks for your help.
Ciao
Tony

**simonskyman** · 06-10-2005

I'm not sure about that feedhorn design,maybe its no good on low frequencies.And it looks too far up but then that depends on the diameter of thefeed horn bracket.

Is there anything in the distance in the general direction of the dish ,like a tv or phone transmitter on top of a hill/mountain etc?
Next thing is to take a photo of a spectrum analyser reading,high /low/horizontal/vertical.
Apart from 2d not working,do you receive all other channels okay no break up?

***snap*** · 06-10-2005

From the pictures, it looks as though the skew is completely wrong, you have it set to around 45-50 degrees, it should be around 11 degrees in Palermo 9.5 degrees in Catania. This is enough to explain why you have no Astra 2D. Re-set it to be just away from horizontal, a little bit towards the current position, and see what happens.
A calculator for skew can be found at:
http://www.satlex.de/en/azel_calc-pa...ountry_code=it

***dave branson*** · 06-10-2005

Originally Posted by snap

From the pictures, it looks as though the skew is completely wrong, you have it set to around 45-50 degrees, it should be around 11 degrees in Palermo 9.5 degrees in Catania. This is enough to explain why you have no Astra 2D. Re-set it to be just away from horizontal, a little bit towards the current position, and see what happens.
A calculator for skew can be found at:
http://www.satlex.de/en/azel_calc-pa...ountry_code=it

I think you will find that the formula is for offset dishes.
I used it on my pf dish and it was way out,my lnb is skewed about 6o deg from horizontal,to the right looking at the dish and it works fine

***snap*** · 06-10-2005

You're right, I didn't think of that- I'm using an offset dish- what else could be wrong- the feedhorn type?

***dave branson*** · 06-10-2005

attached is a picture of my lnb,i do think that the problem Tony has is the feedhorn arrangement

**barney** · 06-10-2005

Originally Posted by dave branson

attached is a picture of my lnb,i do think that the problem Tony has is the feedhorn arrangement

Hi Dave, what is this support? and LNB ?

Thank you
barney

***dave branson*** · 07-10-2005

Originally Posted by barney

Hi Dave, what is this support? and LNB ?

Thank you
barney

The support is with a clamp, fixed to the the support ring which holds the struts for the dish,as the original IRTE LNB holder was not very good.
The feedhorn is an Invacom adjustable type,and the LNB is an Invacom quad.
I recently ordered a Swedish Microwave LNB and am waiting for delivery from a company in Genova.

**ynot62** · 07-10-2005

Hi Dave,
Can you post your picture again?
It seems that I cant open it.
REgarding the feedhorn, this is the one I received from Patriot. They say it should work.
If I wanted to get your feedhorn and your support where could I find them?
To answer to someone else who asked if I was receiving other channels without problems, We know for sure that my dish is not working properly as we are receiving much less channels that I already do with my Offset dish 1.5 mt.
So we know for sure that my Patriot is not working as it should do.
I already used two more different LNbs without any improvement and I am really thinking to do another try and get a different feedhorn.
About the skew, we did all the tests and the way it set now is the best signal reception on most of Astra 2A and Astra 2B.
Im getting very frustrated and very confused too, everything we try doesnt bring to any conclusion.
Ciao for now
Tony
Here is my email if somebody wish to email me and give more advice : info@timeoutpub.com

Originally Posted by dave branson

The support is with a clamp, fixed to the the support ring which holds the struts for the dish,as the original IRTE LNB holder was not very good.
The feedhorn is an Invacom adjustable type,and the LNB is an Invacom quad.
I recently ordered a Swedish Microwave LNB and am waiting for delivery from a company in Genova.

***iceman*** · 07-10-2005

Tony
This one is a very long shot but i cant think of anything else...
Does your feedhorn have a round hole on the flange surface where it bolts on to the LNB?
Some Prime focus dish manufacturers make their feedhorns suitable for single polarity reception...Jonsa does this on the 4.2m dish...Instead of a round hole they come with a rectangular opening designed to allow single polarity..I have to use a round file to enlarge the opening to be able to use universal invacoms...

Likvid · 07-10-2005

The Patriot feed you received is the ADL KU-band version, i don't beleive the problem is the feed, ADL have sold many of these feeds around the world.

I beleive your problem is the dish, i think you haven't assmbled it right.

Does the dish surface feels smooth when you put your hand on it?

If it feels like waves, up and down, there is probably some tension in the reflector panels and you need to re-assemble the whole dish from scratch.

Dishes made of petals are generally a nightmare to get right if you don't do it right from the beginning and the sat folks from Rome did say you got like 12dB higher signal when they put the foot in the dish which means the petals aren't smooth.

**ynot62** · 07-10-2005

Likvid,
even if i wanted to re-assemble the dish again.
How would i know that it will be fine?
To me the dish seems quite smooth but who knows?
Im really frustrated now
Ciao for now
Tony

Originally Posted by Likvid

The Patriot feed you received is the ADL KU-band version, i don't beleive the problem is the feed, ADL have sold many of these feeds around the world.

I beleive your problem is the dish, i think you haven't assmbled it right.

Does the dish surface feels smooth when you put your hand on it?

If it feels like waves, up and down, there is probably some tension in the reflector panels and you need to re-assemble the whole dish from scratch.

Dishes made of petals are generally a nightmare to get right if you don't do it right from the beginning and the sat folks from Rome did say you got like 12dB higher signal when they put the foot in the dish which means the petals aren't smooth.

Likvid · 07-10-2005

Originally Posted by ynot62

Likvid,
even if i wanted to re-assemble the dish again.
How would i know that it will be fine?
To me the dish seems quite smooth but who knows?
Im really frustrated now
Ciao for now
Tony

Have you had any more conversation with Patriot about the dish?

It's difficult with petalized dishes as there are so many factors to consider, especially your dish which got 16 petals.

I beleive you have to talk to Patriot about this and that you got much higher signal when you put the foot in the dish.

**ynot62** · 22-11-2005

Hi Likvid,
unfortunally I didnt get any answer back from Patriot.
Im waiting now for Old Satellite who promissed me to send over some papers which could help me to reassembly my dish.
Thats all for now unfortunally
Ciao for now
Tony

Originally Posted by Likvid

Have you had any more conversation with Patriot about the dish?

It's difficult with petalized dishes as there are so many factors to consider, especially your dish which got 16 petals.

I beleive you have to talk to Patriot about this and that you got much higher signal when you put the foot in the dish.

**ynot62** · 03-12-2005

Hi Guys,
I am back.
It has been 18 months since I bought my Patriot Az/El 3.8 mts prime focus dish and still the bloody dish is working not better then my other 1.5 mts offset dish.
I have two Invacom LNbs 0.3db C120 , a twin and a quad;
My feedhorns are the ADL - KU 850 and ADL - KU 855 both supplied by Patriot.
My F/D is 157.2 cms as Patriot itself told me.
We checked with two strings if the dish was distorted but it seems ok.
One day we just put a foot on one petal very close to the centre of the dish and the signal on Astra 2D went up quite a lot.
Yesterday I was reading once more the Install Manual of my Dish and I noticed for the first time that on point 8 regarding how to assembly the petals, it says:
Starting at the hub tighten all hardware by working outward 1 circular row at the time.
Actually we never followed this procedure but layed them one at the time screwing them to eachother as we went alone.
Could it be the reason why is not working properly?
Maybe we distorted the petals or the alignment is not proper?
If I retighten the dish again could i solve the problem?
Or should I buy a new LNB ( like Inverto or MTI ) or Feedhorn or both?
What about this new adjustable feedhorn ADF 120 by Invacom, and if I buy it how can I match it to my dish? I wouldnt have the right mounting ring.
Ok thats all for now
Regards
Tony

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