Gibertini multi lnb arm

[nml]

I have a Gibertini 1.2 dish with a gibertini multi lnb arm, i wanted it for 28 and 19 east problem is i cant get any significant signal for 19east.
I have the multi lnb centered on the dish lnb arm with the lnb for 28 east there i have then tried a number of different lnb's to the right of that looking from the front of the dish.
I move it along the arm and the best signal i can get is about 35% after tweaking the lnb on that spot.
First time i have fitted one of these normally do motorised can someone tell me what i am doing wrong this should be so simple.


nml

[greyheadrobbo]

Dont know if this helps but i am using a monobloc lnb for 13e and 19e and I
have to slightly tilt the lnb to the left as you look at the dish, so 19e is a little higher,

[echelon]

read through this and you will see pictures of my setup where the zone 2 dish is focussed onto hotbird at 13e

https://www.satpimps.co.uk/showthread.php?t=60102

I did have to lengthen the arm on this setup , as the alternative was a bigger dish with a longer arm , and the ideal may have been around 85cm , but I would have thought it should work fine with a bigger dish like yours

having said that , perhaps you should have the dish centred on astra1 or hotbird and the offsets on the others ?

this would mean the left hand ones are higher up as normal , as it then rises from right to left from the front of the dish

[johnnymac]

I have a Gibertini 1.2 dish with a gibertini multi lnb arm, i wanted it for 28 and 19 east problem is i cant get any significant signal for 19east.
I have the multi lnb centered on the dish lnb arm with the lnb for 28 east there i have then tried a number of different lnb's to the right of that looking from the front of the dish.
I move it along the arm and the best signal i can get is about 35% after tweaking the lnb on that spot.
First time i have fitted one of these normally do motorised can someone tell me what i am doing wrong this should be so simple.


nml

Not so simple these beasts need a lot of fine tuning, your prime lnb need to be set up near the middle of your spread in your case 23.5 E - main reason being the wider the spread the weaker the signal

On that set up, the center LNB needs to be on 23.5, and Astra 2 to the left as you look at the dish from behind the LNB.

Once you have that you can add or slide the center lnb to the left for Astra 1

You will have to alter the skew on you lnb's for strongest signal and even bend the arm slightly up and down on either side.

Good luck :)

[johnnymac]

.

having said that , perhaps you should have the dish centred on astra1 or hotbird and the offsets on the others ?

this would mean the left hand ones are higher up as normal , as it then rises from right to left from the front of the dish

His desired spread is 19 -28 Ech :confused:

The Gilbertini Multiarm does come with 4 lnb holders, if I was setting it up I would go for 13 16 & 19 as well, with 19 as prime and 28 out on its own on the left :)

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This would be next to impossible in Spain, you would get very limited signals on 28 E, I can see why you are trying with it as prime. (Well summised Ech):D

[nml]

Thanks probably wont work then i need as strong a signal i can get with it being in Spain.However i had got the arm in the centre i have got about 7" on each side of the arm would it be worth while moving the arm accrosss to give me more? andcoulyou tell me how far approx the lnb's need to be for 28 and 19 need to be and is this altered by the size of dish?

Thanks again nml

Or should i buy another dish and put a motor on it?

nml

[echelon]

I thought that you may be in spain and therefore 28e would be weaker which is why you are using it as prime focus

my thoughts are that this wont work if you focus on 28e and johnnymac is nearer the mark with a prime focus halfway between the two

its all down to experimentation and of course your location as well

my system works fine for me here in manchester , england , but down in spain it would be different as the signal strengths are different , especially the 28e ones centred on the uk

I suppose you could use 2 dishes , one primed onto 28e and the other for astra and hotbird , and use a diseqc switch as you would be doing anyway

[johnnymac]

28 E is a minefield for Spain there are a number of beams the easiest for you is anything using a south beam, you need to check the beams for your desired channels on a site such as Lyngsat which will also give you your aproximate dish size.

The distance apart is different for evey size dish, to give you an idea you would need a narrow lnb to get sats 3 deg apart eg for 13-16-19 your prime woud be 16 with a slimline Alps lnb, the other two could be standard size but they would be just about touching the slimline lnb.

Motorised could be easier, less cables etc.

[nml]

Thanks again going across next week so will try a few experiments i think i might ultimately have t buy a motor or another dish luckily i am at 4.7 west.

nml

[nml]

Got it 28 east and 19 east strangely the secret was 28 east in the middle of the arm on top 19 east mounted under the arm very good signal strength on all channels including Premiere.
There is no adjustment for the angle of the arm.Has anyone come across this before.

nml