Forgive my ignorance but am I correct that this means squadrons remaining solely Tr1 equipped will be reliant on a mechanical radar based on a 30+ year old design. So the airframes with limited GA capability will also be without the benefits of a modern radar which among other things has improved AI capbility and from a defensive view lower probability of intercept. So for optimum performance they will need to use a Link picture from an aircraft from another unit with a more modern radar also in range of their potential targets?
OK, I know there should also be an E-3 or E-7 but it still doesn't make sense to this bear of little brain.
From what I understand the Tr1 is a very different beast internally, systems and software wise from Tr2/Tr3; thus, as Rhino power said, it would be uneconomic to upgrade Tr1 airframes to a common standard. To me, however, it looks that over the medium to long term, it is false economy to retain rather than replace the Tr1s, however, HMG is unwilling to raise the necessary taxes to pay for replacement probably becaue of the "optics".