If you look on the collar that attaches the LNB to the dish arm, you should see a scale printed on it in degrees. It’s a bit of a coarse scale, but an approximation is better than it being at zero, ot doesn’t have to be spot on really.
To find out if the bay trees are in the way, I’ve just discovered that Dishpointer will tell you how high an obstruction needs to be to interfere with a signal. There is a check box above the map, on the right hand side that says ‘show obstacle’. You can select a point on the map and it will tell you the max height at that point before you will get signal blocked. You need to add to this figure the height of your dish above ground level. Using this, I can see that I have about 3m clearance above my tree. Much easier than using a measure and trig 
The bay trees would have to be about 20 metres high to block my signal.
Judging from the fact that it’s raining, cloudy and windy at the moment, and I’m getting good pictures with 80% strength and 0% quality signals showing in the satellite box settings, I’d say the bay trees are not a problem. Thanks for all that, and what a clever boy DishPointer is!
Bay trees can grow to 30 metres high apparently but if mine are close to 20 metres high then it’ll be a while before they get that high.
Good luck ! 
allow for tree growth? 3m is not a lot
Just climbed up the ladder to have another look at my LNB - it’s a standard LNB - and getting to the top rung of the ladder I could see a scale - never knew it was there - enabling me to skew it. The reception quality went up substantially.
Would it be worth getting a cheap electronic gadget to get the best strength/quality signals, while at the top of the ladder, once I’ve got my new LNB? To avoid climbing up and down the ladder until I’m satisfied with the strength and quality of the signal.
Definitely. A signal strength meter is quite cheap and will allow you to get the best signal possible.
I was sure that skewing the LNB would increase the quality. If you have such good signal and quality, then it may be best just to leave it alone at least for now.
When you do get a new LNB, you need to be a little careful about the size of the ‘collar’ that attaches the LNB to the arm. Looking at yours, It’s probably a 40mm collar and quite a substantial one. Most LNBs are compatible with 40mm collars and if you can, I would use the existing collar rather than any new one if it fits.
Yes, I did note that when looking at Amazon customer comments the words ‘tight fit’ were mentioned, so I shall be careful, thanks.
The old LNB has been horizontal, unskewed, all these years! Anyway, the scale had no markings so I skewed it a bit to the left, which improved the quality.
I’ve now ordered a twin LNB from Amazon,…
https://www.amazon.co.uk/gp/product/B08D6QFHM5/ref=ppx_od_dt_b_asin_image_s00?ie=UTF8&psc=1
and I think I might get this meter…it’s cheap but won’t be using it often.
It’s also available from Amazon Germany at a lower price - and probably faster inter-EU delivery…
This one should be OK, as the LNB is compatible with a 40mm collar. However, the bracket supplied is designed for a Sky MK4 dish,which may not fit onto the arm on your dish. It doesn’t really matter, it just means you may need to use the bracket you already have, which should be fine.
A twin LNB fitting into a currently single existing mount? Usually a legacy mount internal fixing to the arm rather yhan the more recent external mount?
I will have to - I measured the arm of my dish after I ordered the new LNB, and it measures slightly less than 35mm. Shows how much of a satellite dish & and all that stuff, dumbo I am! But I’ll be an expert after all this! For next time, or if a neighbour asks!
When you say the arm is 35mm, is that the width of the rectangular tubular arm that comes from the dish, or the internal width of the circular black collar that clamps onto the LNB ? I would have thought the collar would be 40mm internal diameter.
If it’s the width of the arm that is 35mm, then you will almost certainly have to use the existing collar as many feed arms are 26mm wide (Sky ones) and the collar you get with the LNB will probably be compatible with those. If it’s the collar that is 35mm, then the LNB you bought may be a tight fit with the existing collar. You’ll just have to try it so see which is best.
It’s the width of the dish arm that’s 35mm. I’m not too worried about maybe even ordering another LNB - the right one, that fits. Expense is not my concern - getting TV is. I’ll see what happens when next I’m up the ladder, which will be next Friday when the LNB arrives. If I can get the new LNB to fit the old arm, then I’ll do that.
From (bitter) experience, be careful with the plastic bits, they can get brittle and break. I was doing the same, upgrading from a double to a quad LNB, bloody thing broke where the arm joins the dish. 
Thanks, I can be extremely patient and wary when needs be. We’ll get there in the end!
Thats wide, most of the early ones were 30mm wide and require the adapter I showed above that slides inside the arm. 35mm could be tricky to find.
Next time I’m up the ladder I’ll remeasure - tricky when you’re on the highest rung of the ladder, at my age!
