Only Vertical polarised channels being picked up since dish moved in storm

rock22

Header says it all really.

My dish moved significantly during the storm. Corrected it and all well ( except for CNN new channel). It then moved again during high winds on Friday. I adjusted it again but found it more difficult this time to tune in with the satellite finder.

Anyway, I now have most V polarised channels but H polarised channels are not coming in. Is this just a matter of more fine adjustment or are H channels weaker? Or does it indicate some other problem? The LNB is at least ten years old so wonder if that might need replacing?

I have a Ferguson Ariva box ( about 5 or 6 years old)

The Cush

Try adjusting the LNB skew

How's the LNB feedhorn cover, any crack on it could allow moisture ingress and cause issues internally.

swoofer

It will depend how much adjusting you did, did you touch lnb? change elevation, any obstructions, use CNN as your fixer ie when yyou get that dish is correct. If its a sky lnb then all you do is as above adjust skew, looking from front turn clockwise.

IMG_9191.PNG

rock22

Thanks. I will try again. I think the skew is correct. I find it hard to make minute adjustments with the disk, itis stiff and difficult to make small movements

Tony

Check the F connector for any water ingress. Hor channels use a slightly higher voltage down the coax so any bad connections might cause you to lose Hor channels

rock22

I have checked all connections and spent some time with fine adjustment. The app I have suggest a skew of 24 degrees which I have set, it was about that anyway. But I also tried it at 12 degrees.

I am getting an intensity and quality of about 90% on BBC1-4 but BBC Alba and BBC2 NI I am getting intensity(strenght) of 45% and quality of 10%. Same for ITV1-3 ( butITV4 is fine ). All the V polarised channels are coming in at 90% and all the H channels are coming in intensity of 45% and quality of 10%.

Could it by a faulty LNB or a faulty box ( I am using a Ferguson Ariva)?

Just to add, it all worked fine before the storm. The dish was swung around completely by the winds. It did work fine for about a week until more recent gales last weekend. ( I am situated in West and it is quite windy recently)

The Cush

Possibly the LNB, they're cheap enough enough to buy.

Without a meter troubleshooting can be awkward.

Does the feedhorn cover look intact?

rock22

No the cover is actually cracked a little. I will try getting a new LNB and see does it make a difference.

thanks

The Cush

https://www.boards.ie/discussion/comment/123217081#Comment_123217081

That's most likely your problem so.

Moisture ingress into the electronics of the LNB via the crack on the cover. Behind the cover is the waveguide the incoming signal "bounces" along until it interacts with the vertical and horizontal probes to downconvert the frequencies to a suitable level to be carried down the cable.

Replace the LNB.

rock22

https://www.boards.ie/discussion/comment/123217149#Comment_123217149

Thanks. I have no idea where to get an lnb. I did search online but wonder if there is a brick and mortar store in or near Galway? Or what I should order online. Do I need Freeview lnb, universal lnb, wideband lnb or does it matter?

thanks again

The Cush

Freetv and Satworld online Irish stores.

I don't know Galway, so can't recommend.

Is it a Sky dish or a non-Sky dish, different size LNB mount for both.

swoofer

This is what you need, at screwfix galway

https://www.screwfix.ie/p/visiblewave-4-output-universal-quad-lnb/734gv

but a pic of the dish would be useful just in case

rock22

Thanks. It is not a sky dish. It is larger, almost 800 mm I think. The LNB is held by a ring which is clamped around it.

Hopefully clear from this photograph.

Incidentlt, two cables from the LNB but both terminate in the same room and only one is connected to the Ariva Box.

rock22

A further photograph of the dish

The Cush

https://www.boards.ie/discussion/comment/123218203#Comment_123218203

That LNB is for a Sky dish.

You require one of these non-Sky dish LNBs

https://www.freetv.ie/satellite/dishes/universal-lnbs/

Tony

https://www.boards.ie/discussion/comment/123218483#Comment_123218483

you need a 40mm collar (non sky type) LNB

rock22

https://www.boards.ie/discussion/comment/123219191#Comment_123219191

Perfect. Thanks

swoofer

the Cush I showed sky lnb in Galway and then asked for a pic of the dish? And if push came to shove you can get an adapter to make it 40mm. You make my post look like I am telling him wrong.

And the dish is out it’s needs adjustment.

The Cush

https://www.boards.ie/discussion/comment/123221236#Comment_123221236

His dish has a 40mm collar.

The Sky Mk.4 LNB has a 37mm neck.

So 3mm difference.

Solution: tape up the Sky LNB neck to ensure a snug fit with the standard dish collar.

The old Mk.3 dishes had a 40mm collar. Mk.3 to Mk.4 adapters are available to take the newer smaller neck Sky LNB. And iirc a Mk.4 adapter to Mk.3 LNB was also available.

I assume Sky changed the collar size so that non-Sky LNBs couldn't be used on Sky dishes. Sky LNBs are designed for the shape of the oval dish.

Using the wrong LNB could affect reception of marginal frequencies.

rock22

I hope I haven't started a row. I fully appreciate all the advice from everyone.

In what way is the dish 'out' ? I turned it to the strongest signal using a digital sat finder I bought many years ago.

dxhound2005

https://www.boards.ie/discussion/comment/123221780#Comment_123221780

You said in your OP that you were not getting CNN. If you get CNN when you replace the LNB then the dish is probably not out.

https://www.lyngsat.com/muxes/Astra-2G_Europe-Ku_11671-H.html

rock22

Thanks

i have bought the LNB from Screwfix and will try fitting tomorrow. It seems to have 40mm diameter. I will report back when I have tried it

The Cush

https://www.boards.ie/discussion/comment/123223492#Comment_123223492

Thanks, hope it works out.

goldiefresh

https://www.boards.ie/discussion/comment/123223492#Comment_123223492

I can confirm the labgear lnb in Screwfix is 40mm and comes with a 40mm adapter. Have used quiet a few of these on universal dishes. Iv ended up with a few spare Adapters as a result.

The Cush

https://www.boards.ie/discussion/comment/123223924#Comment_123223924

So it's 40mm neck, standard universal LNB with the adapter for the Sky dish?

The Screwfix website lacks this basic information.

Thanks for the hands-on info.

swoofer

Reading back I noticed you have 2 cables but only one in use? I have to ask did you try the other one? That dish looks like a traix and at 80cm you should get everything easy but as dish is bigger aligning is a bit trickier. I am in clare and get CNN with 90% signal and 14.6db with 68CM dish. db is better but some boxes wont show it. I use VU+ boxes and inverto lnb's but for 28east lnb should not make a great deal of difference.

There are a few version of the ariva, 150, 250 and I don't know how good tuner is.

When changing lnb you probably know the 2 plastic lugs release it and pull out.

I would not run cables through lnb arm, its easier to make a nice weather loop if you tape cables to arm and avoid unnecessary bends.

For your location I used galway city and dish elevation is 20.3 and its 20.6 for me. The skew is -16.8

and -17.1 for me.

One tip you may not be aware is focal length and that is the distant between front of lnb and dish face, moving that in and out will find the hotspot.

I use al jazeera and CNN to align as both are weak in comparison to say BBC1/ITV. One is H and the other is V.

On looking at dish, to me it looks as if it is too low at front,(elevation) but not a lot and could be an illusion.

I await results😀

goldiefresh

https://www.boards.ie/discussion/comment/123223933#Comment_123223933

That's correct. I have used single universal lnbs with the spare adaptors on mk4 dishes.

The Cush

https://www.boards.ie/discussion/comment/123224788#Comment_123224788

I've seen dishes installed like this, dish appears to be pointing too low but is seems to be down to the parabolic design/style of dish installed

rock22

Well thanks again for all the help. Yes, I did try the other cable with the same result.

SO I fitted the new LNB ( from Screwfix) and all it working perfect. CNN and Al Jazeera are both around 90% for both strength and quality. And all other channels are coming in fine as well.

I think the dish looks too low at front too but it aligns to the 20 degree mark on the bracket. Mind you the bracket looks to be slipping slightly too. The bracket must be thirty years old although the dish was replaced about 10 years ago.

Anyway, I am very grateful for all the advice and help. Much appreciated

swoofer

Perfect job done.