How many times can you spot the letter "b" in:
relayed by the Castle hill transmitter.
Asssuming your TV picture is ok then the problem lies elsewhere in your equipment.
Having said the above given you have gone to expense of buying a wideband aerial, there is little to be gained by aiming it at the Glossop site.
Depending where you live in the glossop area it may be worth pointing your new aerial at Winterhill (or even Emely Moor) to obtain a much better selection of Freeview channels.
On the topic of DAB...
Whilst it is correct that Castle Hill does NOT transmit DAB it is possible to obtain DAB radio in the Glossop area.
In general Digital One (Commercial) coverage is better than that provided by the BBC.
at Torside & Woodhead to improve reception for drivers.
Andrew: You might find Ofcom DAB switchover coverage planning proposals | ukfree.tv - independent free digital TV advice interesting.
Tom: The BBC radio channels are carried on the same multiplex as the TV channels, there should be no difference in the signal level as they form part of the same transmission. See How digital television works | ukfree.tv - independent free digital TV advice .

user
I found twenty-three "b"s in the provided passage.
assistant