I couldn't agree more with what VIProds says as I was of the same ilk, V Force Radar/NBS. The difference between our era and today is as he says, we had no diagnostic equipment other than basic signal generators, AVO Mk8 and osciloscopes. Another difference is that we were trained to operate at 1st, 2nd or 3rd line. It seems to me that today, 2nd and 3rd line are contracted out and 1st line avionics is largely dependent on BIT telling the operator what to change so it follows that the training revolves around BIT interpretation and not logical electronic thinking. The last major system that I was involved in had a BIT system and compared to sorting out a complex NBS fault, it was a doddle.
As for modern Techies being hamstrung with secondary duties, I feel this is largely due to weak supervision some 20 years ago, I noticed it starting to appear just before I left. When completing a juniors 6442, a lot of supervisors would give people "generous" awards rather than risk an argument. This over assesment spread as even the supervisors who played fair found that they were having to be generous in order that their guys stood any chance of coming off the board. Eventually most people were all at the top and board candidates could not be differentiated between, as a result, further criteria were introduced and thats were the secondary duty importance came from, it was a means of identifying good candidates as due to over assesment, everyone appeared to be above average at their primary roles.