Do all LNBs have a standard fitting to the dish arm ?

[bob.g]

I have a 70cm elliptical dish, installed some years ago with a single LNB to receive Freesat from Sky. I now want to purchase a Humax Freesat receiver and wish to upgrade the dish to have a quad LNB.

Do I need to take care about selecting an LNB with the correct fitting, (and if so how do I measure and describe the fixing on my dish) or do they all have a standard size connection to the dish arm ?

 

[daveh75]

I have a 70cm elliptical dish, installed some years ago with a single LNB to receive Freesat from Sky. I now want to purchase a Humax Freesat receiver and wish to upgrade the dish to have a quad LNB.

Sounds like a Raven Gemini? or similar. http://www.raven.co.uk/satellite-products/G-50.htm

In which case it'll have a standard 40mm clamp/LNB bracket.

Do I need to take care about selecting an LNB with the correct fitting, (and if so how do I measure and describe the fixing on my dish) or do they all have a standard size connection to the dish arm ?

Standard type universal LNBs have a 40mm neck (to fit the standard type LNB bracket) though you can also get 'bullet' or 'narrow feed' LNBs that have a 23mm neck, but they're usually supplied with a 23mm to 40mm adapter.

Just avoid the LNBs meant for Sky dishes, as they have a different type of fitting altogether (usually either a spigot/finger type fitting that slides into the feed arm and held in place with a peg or on the latest dishes, a saddle fitting that sits over the feed arm)

 

[bob.g]

Thanks. My dish is similar to that pic, but not the same. The rectangular arm has external dimensions of about 30mm x 20 mm.