Originally Posted by Dave5158:
“As far as I am aware; standard analogue channels can't carry the necessary switching signal that your TV needs to make it switch to widescreen.
Unless someone knows different, I think this may be the reason for your 'problem'.”
They don't need to. With the exception of PAL Plus there are no widescreen analogue programmes broadcast.
Everything is 4:3. Any "widescreen" content is actually a 14:9 picture embedded in a standard 4:3 frame. Hence the narrow black bars top and bottom. A Widescreen TV can zoom into this area and expand it out to fill most of the screen. Though as it is 14:9 rather than 16:9 there will be bars at the sides.
On digital services however the broadcasters can use anamorphic widescreen This uses some special compression to squeeze a 16:9 picture into the 4:3 frame broadcast. A 16:9 telly then reverses the process to display it full screen.
A Freeview STB connected to a 4:3 TV however stretches the picture then either puts it into a 4:3 frame with black bars top and bottom, stretches it out then crops it to 14:9 and puts it a 4:3 frame with thiner black bars top and bottom or stretches it out and crops to 4:3. The latter two losing some picture detail at the edges.
And PAL Plus required a PAL Plus compatible receiver to make use of the hidden data. Most sets are not PAL Plus so just display the 14:9 picture embedded in a 4:3 frame.