Posted: Thu Aug 31, 2023 10:59pm
YOur dish is large enough where you are to receive the channels. (I have a 125x135cm dish just up the road from you that just about gets all channels, including those that you say you have lost - apart from in heavy rain - so your dish that is twice the size should be fine.)
It just needs the correct alignment, and good LNB which also need to be realigned... or replaced, as they do fail,+ they do not like hot temperatures!
Trees in the line of sight will block the already weak signals reaching the dish - check this by taking a photo from the centre of your dish, to the LNB and to the Sky. any tre+es in the photo will affect the signals, so consider cutting, or moving the dish.
"I am 100% certain that the dish can't have moved as it's in 3ft of concrete." - again you said this before...but it only has to move a few millimeters for the dish to move out of alignment. Earthquakes (been a few f the this year), and rain (weakens the ground underneath and the dish shelters more) can shift the concrete block. Been to many where this has happened, especially after when we had pretty much the whole of April in rain. And the big 2.4m dishes do move in strong winds (they are not idea, as they can "click" inand out of alignment easily) , they can also warp. And most of them i have seen have never been installed correctly or accurately as the rear "ring" is never 100% accurate, to a few washers are needed to reshape the dish to its optimum.
"I have connected the box to my WiFi in the hope I can recover the missing channels but will need to use the HDMI output." - Connecting the TV to your Freesat box with different cables will not restore the channels that you have lost, which are down to signals to your dish, not signals from your box to your TV. Of all the Freesat boxes I have used, the number of channels I receive has been the same no matter if using component or HDMI...it makes no difference, and makes no sence in thinking it will be any difference.
IF you want to get content from the internet (which i assume you mean "by wifi") on your Freesat box like iPlayer and UKTV for the channel that you have lost on the Freesat box, then you will need to connect the box to a router running a VPN or Smart DNS service, that is in turn connected to your main router. But then not all the channels you have lost are available live on the apps on Freesat.
"Can you get a D to A converter that actually works without resorting to something Chinese? HDMI input and SCART output." - most will be made in China. and most will be HDMI to component, which you then have to convert to SCart. But again, if you are losing channels due to bad signals, it is nothing to do with ther connection between your box and your dish!