Good sites:
Lots of info on how UK Freeview works, how MUXes are structured and which channel is on each, and info on the 700 Mhz clearance programme:
https://www.aerialsandtv.com/knowledge/digital-freeview-tv#700mhz-clearance
TV Signal strength info and advice:
https://otadtv.com/digital_tv/signals.html
UHF Channels and corresponding frequencies :
| UHF channel number | Frequency (MHz) |
|---|---|
| 21 | 474 |
| 22 | 482 |
| 23 | 490 |
| 24 | 498 |
| 25 | 506 |
| 26 | 514 |
| 27 | 522 |
| 28 | 530 |
| 29 | 538 |
| 30 | 546 |
| 31 | 554 |
| 32 | 562 |
| 33 | 570 |
| 34 | 578 |
| 35 | 586 |
| 36 | 594 |
| 37 | 602 |
| 38 | 610 |
| 39 | 618 |
| 40 | 626 |
| 41 | 634 |
| 42 | 642 |
| 43 | 650 |
| 44 | 658 |
| 45 | 666 |
| 46 | 674 |
| 47 | 682 |
| 48 | 690 |
| 49 | 698 |
| 50 | 706 |
| 51 | 714 |
| 52 | 722 |
| 53 | 730 |
| 54 | 738 |
| 55 | 746 |
| 56 | 754 |
| 57 | 762 |
| 58 | 770 |
| 59 | 778 |
| 60 | 786 |
| 61 | 794 |
| 62 | 802 |
| 63 | 810 |
| 64 | 818 |
| 65 | 826 |
| 66 | 834 |
| 67 | 842 |
| 68 | 850 |