Advice Needed Cheap LNB on large dish works

[JamesSw]

Hi
I just did an installation in the foot hills of the Pyrenees and found a strange phenomenon. I usually use a 80 cm dish and an Inverto Black LNB here 100 miles north of the Pyrenees and get a signal quality figure of 13db on my meter for the UK beam channels. I installed a 120cm dish with an Inverto Black double and tried to point the dish for BBC 1 London and got nothing (2.5db) , I tried ITV and go to 7.3 db (it locks on 6.5). I then put a cheaper single feed LNB on and got 8.3db for both BBC1 and ITV.

I tried another 'good' twin LNB and another cheap single and the former didn't work and the later did

Can anyone explain why this is happens?

 

[Archived-1]

Hi, out of interest to me could you check the DB of each lnb you've tried and its positioning in the holder and the length of your cable run approximately please .

 

[JamesSw]

I can only tell you what I remember as the dish is 100 miles away -
Inverto black double BBC1 2.5 db ITV 7.5 db
Best double roughly BBC1 2.5 db ITV 7.5 db
Cahors single LNB BBC1 8.3 db ITV 8.3 db

I put the lnb in it's holder such that it gets the best signal
The cable run doesn't matter - I am plugging my meter into the LNB (First strike FS1)

 

[Archived-1]

Many thanks, cable runs can make a difference, if your testing close up with a meter you could well get a different reading at the end of the run, but I am not getting into a debate about this, thanks for your time and I hope you get to the bottom of it

 

[archive10]

Many thanks, cable runs can make a difference, if your testing close up with a meter you could well get a different reading at the end of the run, but I am not getting into a debate about this, thanks for your time and I hope you get to the bottom of it

Agree. I use an 8'ish meter cable to get some "distance" to the LNB when measuring.
It is also easier to wave a meter around on a ladder with a longer cable, as you cannot move your body around too much...