'63-'65 was probably the last time the Vulcan ECM kit was of any great use.... By the time I did the Vulcan OCU, the senior AEOs reckoned that there were but a handful of Soviet radars against which it might have been of any use....and were rightly scathing about the RAF's reluctance to upgrade it.
In 1979, the US had to find something from a museum against which we could react in the EW phase of GIANT VOICE.
Although the Vulcan was given an ECM update for OP CORPORATE, of course. But the 'I band jammer' fitted to the Waddington fleet was a real Sparrow magnet for HOJ or RSOJ attacks - and I'm pretty sure that the Sovs had a similar capability by then.