Differences between LNBs

dimi_ts1

Hi,

Apologies for my ignorance but can anyone explain me differenceies of LNB’s.
Are they different LNB for Sky +, Hotbird, Freeview, and Astra?
Are the Quad LNB’s any worse or better than single LNB’s?
I have an 80cm COMAG dish and I want to install 3 LNB for Hotbird, Astra and Eurobird. All of each on is at a different elevation and skew. How can I set the LNB’s when all the multibrackets are not skew or elevation adjustable?
Many thanks

HB13DISH

I have moved your post to here.
Please don't hijack other member's threads with unrelated request.

guest

SkyDishes require an LNB with a pin and peg fitting.

Proper dishes up to around 1.2m use 40mm Collar fittings.

Commercially available multibrackets are arc shaped to take account of the required position for each LNB to attain the desired Elevation.

Skew is adjusted by slackening the 40mm collar securing each LNB and rotating in the appropriate direction.

Which Eurobird (there are several) and which Astra (there are several) are you referring to?

Freeview doesn't use Dish/LNB as it is a Digital Terrestrial system requiring an Aerial.

Multiple Output LNBs like Twins, Quads and Octos can be better or worse than singles! Theoretically each output would perform as well as the equivalent single output device. But faults, quirks, experimentation and experience mean that you can't always rely on that.

satelliteman

Also worth noting that LNb internal scaler rings differ for sky mini dishes to that of standard round type dishes where the rings are circular.



The bracket will be adjustable to allow for Elevation differences between satellites.

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nanochickin

You'll be needing something like the picture below

This is the 85cm dish i put up last year for a friend in Paignton. It is set up in the same manner as what you require.

The main focus on the dish is on Astra 1 19.2e, the lnb on the left is for Hotbird 13e and the one on the right is on Astra 2 @28.2e.

Just remember when setting up this type dish setup that the lnbs are setup as if they are mirrored

Normally if you need to move the dish to the left to get a signal if you just add a second lnb instead you will need to put it to the right due to the mirror effect the dish gives when it bounces the signal to the lnb

The brackets can be found on Ebay. If i remember rightly i got them form a German supplier for about €6 as they were cheaper than any uk supplier i could find

Don't always presume that just because an lnb shows a 0.1db noise level that it is any better than one that shows 0.6db.

I had to change my Triax 0.2db Quad lnb after 2 of the ports failed on it. The only one i had to hand at the time (The only one in the back of the Van) was a Televes 0.6dB Quad lnb. I fitted it with the intention of changing it when i could get another 0.2db one.

The Televes lnb outperforms the Triax one even allowing me a sniff of 7w every now and then, I have decided to keep it on the dish as it works really well with it



Nano

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dimi_ts1

Apologies HB13DISH. I am still trying to find my way in the forum.

Thank you Rai uno
SkyDishes require an LNB with a pin and peg fitting.
So that means that all LNB’s are the same internally and only the mounting differs.

Commercially available multibrackets are arc shaped to take account of the required position for each LNB to attain the desired Elevation.
I am sure that what you say is correct but the ones that I have found they are only arc shaped, OK for the satellite position but not good for the elevation. Maybe I do not look for at the right place.

Freeview doesn't use Dish/LNB as it is a Digital Terrestrial system requiring an Aerial.
My mistake. I was referring to Astra 2 @ 28.5E for the sky and free BBC channels.

Also worth noting that LNb internal scaler rings differ for sky mini dishes to that of standard round type dishes where the rings are circular.
I am sorry for my ignorance but I do not know what Scaler rings are. The installed dish is a 80cm non circular COMAG. Will a standard LNB be OK for ASTRA 2@28.2E for Sky?

Thank you nanochickin

The dish in the photo looks the same as the one that I have
Just remember when setting up this type dish setup that the lnbs are setup as if they are mirrored
Normally if you need to move the dish to the left to get a signal if you just add a second lnb instead you will need to put it to the right due to the mirror effect the dish gives when it bounces the signal to the lnb
Now that did confused me. As the dish is pointing 19.2E Astra 1 then I will have to put the second LNB 6.2deg to the left of the ASTRA 1 19.2E to get Hotbird 13E. What do you mean by mirrored?

The brackets can be found on Ebay . If i remember rightly i got them form a German supplier for about €6 as they were cheaper than any uk supplier i could find
Do you remember form where?

Don't always presume that just because an lnb shows a 0.1db noise level that it is any better than one that shows 0.6db. I had to change my Triax 0.2db Quad lnb after 2 of the ports failed on it. The only one i had to hand at the time (The only one in the back of the Van) was a Televes 0.6dB Quad lnb. I fitted it with the intention of changing it when i could get another 0.2db one.
The Televes lnb outperforms the Triax one even allowing me a sniff of 7w every now and then, I have
decided to keep it on the dish as it works really well with it It sounds that you also have to be lucky to get it right

Robbo

Yes, a standard universal LNB will work for Sky/28E, it's only the feedhorn (with the scalar rings in it) that are different between what is used for standard dishes and Sky minidishes.

Mirrored-

Say you stand behind dish looking up to the sky where the sats are, the LNB to the right of the focus will pick up satellites to the left in the Sky, and vice versa.
The same goes for the elevation, put the LNB lower and it will pick up a satellite that is higher.

I bought a bracket that looks very much like the one Nano used from Ebay, worldwidesatellite I think it was £10. With those type, you have to make sure that the LNBs have a long enough neck, as they fit around the main LNB, an exampleis the Smart Titanium.