Why can't I get Nilesat Vertical in Oxford with 2.4m dish?

[Skeletor]

Guys I'm unable to receive the vertical polarities from Nilesat at 7.0 degrees West.

I've installed a Andrews 2.4 m dish with a 0.3dB Inverto Quatro C120 flang LNB and Andrews matched feedhorn.

Strangely I can pick up a number of Horizontal polarities such as 12149 Horizontal and view the channels but no vertical polarities at all.

There are many threads stating that the vertical polarities can be received and not the horizontal. I have the opposite problem.

Dish install just outside Oxford.

Does anyone have any ideas?

Skeletor

 

[Robbo]

Why have you used a quattro LNB???? Are you feeding a multiswitch?

If not, then the quattro is not suitable, you need a quad.

 

[Skeletor]

I'm using a Quattro LNB as I'm feeding a large private IRS system.

 

[rolfw]

The 2.4m should be more than adequate (a 1.8m offset Andrews works fine in Berkshire), so it is possibly misalignment, inaccurate assembly, a faulty LNB/multiswitch or incorrect connections. Try a standard universal C120 LNB to align and test, then connect to the system.

Is this a prime focus petal dish or offset 2 piece and have you set one up before?

 

[Skeletor]

The dish is a 2.4m offset dish.

I've installed many offset dishes in the past but not of this size. Also I normaly use a 40mm flange LNB on the smaller dishes and not a C120 flang.

I realigned the dish to a different satellite position and could receive both the vertical and horizontal polarities.

Due to the above I cant understand why I'm only receiving the Horizontal polartie for Nilesat.

 

[Skeletor]

I'm also using a Swire Annie spectrum analyser for alignment.

 

[rolfw]

For that dish on KU band you need a C120 flange LNB fastened to a Ku band feedhorn, there is obviously something wrong, as otherwise you'd be getting both polarities. As I said above, align with a single output LNB then you can easily switch between the bands and polarities to test.