You've asked this question several times before!
The maximum (reliable) range of
any transmitter in the frequency range used for FM broadcast radio in this country isn't much more than about 50 miles. (You can receive national stations, such as BBC Radio 2, all over the country simply because there are lots of different Radio 2 transmitters spread across the UK). Further, such transmitters often 'beam' in a particular direction, to serve specific areas. (i.e. you could be fairly close to a transmitter but on the 'wrong side' of it and so still not hear its signals).
So, unless you're within the designated broadcast area for BBC Radio Sheffield (or, at least, very close to it), it's IMPOSSIBLE to hear that station on FM. i.e. you MUST be within this area to receive BBC Radio Sheffield on FM:
https://i.postimg.cc/k50f3f1v/Radio-Sheffield.jpg
Up until last year, BBC Radio Sheffield had a medium wave transmitter, from which signals could sometimes be heard outside of the designated transmission area. However that has now been turned off. So there is now no means of receiving BBC Radio Sheffield from any great distance purely using radio waves. The ONLY way to receive BBC Radio Sheffield from afar is via the internet.