Ah - I see.
The local feed, of course, straight from the RPi, doesn't filter or delay anything. I haven't set it up to do so, but it could be seen by anyone if I fiddled with the router a bit. The input is line of sight, but we can see aircraft as far north as Cambridge and well out over the sea to the south.
Early days as yet, I'm not rushing to change anything, though I am encouraging locally based members to spend the cost of a quarter of an hour in the air to set up their own.
B