No not TCAS equipped but I don't believe many mil aircraft are. Cardiff's radar service is limited in our area however and below top of drop is not much protection.
I wouldn't operate IMC with no radar and RT either unless I really have to (not much radar coverage in the wee small hours on a job inland away from major airports).
Operating in the cruise IMC and flying quadrantals to ensure separation is not the same as descending IMC to cloudbreak/land with no radar or RT (or worse, pretending you are VMC so ATC don't panic).