The current Bilsdale television transmitter is a guyed mast (space frame type) of 306m height and began transmissions on the 22 May 2023. It was built as rapidly as possible to replace the previous transmitter which was seriously damaged in a fire in Aug 2021, see article below.
The original 1969 (309m) mast was also guyed but was of tubular construction. It was identical to Waltham and Mendip, though it was built by JL Eves (now Babcock) whilst the other two were constructed by BICC (now Balfour Beatty). The Bilsdale mast was a tubular structure all the way to the top (unlike Winter Hill) and had in internal lift, though this was out of use after 1995 following the accident at Belmont. The transmitter was originally owned by the BBC before being sold off to Crown Castle (Castle Transmission International - CTI) then to National Grid Wireless and finally to Arquiva (sic).

The transmitter site is about 15 miles SSE of Middlesborough, it can be seen from the A1 on a clear day. As one travels North it's on the right. A slightly better view can be had from the railway line (between York and Darlington) as it is a little closer, perhaps 12 miles away. The A19 from the A1 up to Teeside passes closer still.
Due to the fact the 306m mast (see How High is High ? ) was built on a 376m mountain the overall aerial height/altitude is 682m (2250ft) and unsurprisingly this is one of the highest in Great Britain. The latter fact obviously helped its transmission range, but like all transmissions they are subject to the "line of sight" rule, even with a "high gain" aerial !

Bilsdale's population coverage is around a million. Many of those in York, Darlington, Stockton, Middlesborough, Hartlepool, Sunderland and Harrogate use Bilsdale's transmissions, though it can also be received at sites on high ground in Sheffield, that's 70 odd miles away!