Question for the big dish men

[kerrywez]

Hi all,
I have been over the see the big dish that I am getting and have some questions for the big dish men.

The dish is a full 2Mts and is a prime focus one, but the LNB that the guy has on it is not the right one. The LNB holder is just a circle that measures 6.5Cms across. It has a very heavy duty polar mount and ground mount, which are in good nick. The actuator is only an 18Ins one and is knackered, but I have a brand new 36Ins heavy duty one for it.

What I would like to ask is what LNB would I need for the dish, I assume that it would need to be a 120 flange, but have no idea what is involved or indeed what a 120 flange means and need to know what I need to mount the LNB? I need to have this matter of the LNB and what I need sorted, before I go to get the dish and take my 1.2 CM down. Any and all assistance will be most welcome and appreciated.

Very best regards Wez

[crossbones]

As it is prime focus you are correct, you will need a C120 lnb.

The C120 lnb bolts on to a feed horn. This depending on the focal distance of your dish.

Do you know the make of your dish?

[robbo71]

I don't know too much Wez, but I do know is that you will need a feedhorn suitable for the dish and then bolt it onto the C120 LNB.

Also you need to find out the F/D ratio of the dish so that you can get a feed horn to match. Invacom do the C120's they may even do a feedhorn.


F/D calculator-

http://www.satlex.de/en/fdratio.html

This may alsobe useful

http://www.invacom.net/invacom_products.htm

[crossbones]

Just like to add Inverto do a good cheap C120 lnb.


Take a look here for some ideas regrading universal feed horns. (but a little pricey!)

-http://www.satellitesuperstore.com/feedhorn.htm

[kerrywez]

I had a look at the back of the dish, but could not find anything, it is just a plain white dish and seems to be round, rather than elliptical. I suppose I will need to have look at the products where Robbo has given me the links to. Thank you both very much, I need to log off for a while now to look at a special program about the late Robert Dunlop, so will be back in a while.

Very best regards Wez

[Jimdefruit]

If its a prime focus dish then the lnb support arms should put the lnb right at the focal point of the dish so there should not be a problem. If the mounting hole is 65 mm then it is too large for a normal cm120 feed horn which is normally 25 mm diam.

The main reason for a feedhorn is to cut out any signals and hence noise from the area around the dish.

As has been mentioned above, try to find out the make of the dish and try to get a matching lnb assembly.

[kerrywez]

Hi Jim.
In the link that crossbones gave me there is a universal fitting for any dish and it might just be the one that I need. I have to take the bloke's meter back to him on Monday so I can have a good look then and I shall take my camera with me and will be bale to post some pics of the dish and the mounting for the LNB, I am sure that would be of great help to you all and in the end help to me as you will be able to see what I am talking about. Thanks for the help and I look forward to hearing what you think when you see the pics of the dish.

Very best regards Wez

[nanochickin]

Try to PM RD100. He seems to really know his stuff about the bigger dishes

I also get the impression that Likvid like to play with them aswell



Nano

[kerrywez]

Hi all got a few pics of the 2Mtr dish, it is very dirty, but I am not worried as it will clean up well. I hope the pics are not too big for posting.

[crossbones]

Not sure what dish that is, maybe one of the other guys will know.

A feed and holder something like this would do the job.

Or you could modify the current holder and just buy a universal feed horn