That was a few years ago I have since tried several other Lnb's the best was the Inverto Black Ultra 0.2,
I took a photo of the Gibby with the IBU & the comments came back that I had the Lnb too far forward in the Lnb holder well it worked for me so I left it,
Then a few days ago some Lnb tests here with a couple of Lnb caught my eye so I tried them on the Gibby & they did not work very well ?
This was the Golden Media 201+ & the Inverto Premium PLL
So I thought back about the Lnb position & decided to saw 23mm off the end then bolt the Lnb holder back on well if it did not work I could always add the sawn bit back on ,
But to my astonishment the new Lnb's performed very well.
Signals that were not there before now boomed in,
I then put the Inverto black ultra back on but this time much further back in the Lnb holder & the signals were vastly improved also the rain fade was less as the Lnb was getting more signal in its new position on the shortened Lnb arm.
https://www.sat-universe.com/showthread.php?t=315374&page=5