We haven't gotten around to limiting anything's dates of availability just yet, but I'm pretty sure we've something here that might be useful. I do know that they got their radar after the first-line DD, and at about the same time as the 2nd-line DD, so starting in mid 44 probably, but I'll look and see. That might have only been new construction getting it in 44... The "leadership" of the IJN thought that the eyesight of their sailors was better than radar, and didn't want to be bothered with technology. Besides they had better things to spend their money on. but it wasn't ASW...