in January 1960 Nikita Khrushchev had announced the development of a "fantastic" Soviet weapon, one which could even destroy all life on earth if unrestrainedly used.
In 1962 the ebullient Khrushchev was forced to back down and lose face before John Kennedy, in the Cuban Missile Crisis.
Khrushchev's missiles and bombers were in woeful shape, as Kennedy well knew (by courtesy of the Russian spy, Colonel Oleg Penkovsky). Kennedy did not know that Khrushchev's new superweapons were nearing deployment, but were not quite ready yet.

To save face and prevent his immediate ouster, Khrushchev apparently conducted a startling two-strike demonstration of his new weapons as soon as they became operationally ready, on April 10, 1963 he detected and destroyed the U.S.S. Thresher nuclear submarine, using a scalar EM howitzer in the underwater "continuous" mode.
The next day he demonstrated the "pulsed" underwater destruction mode for underwater subs by producing a giant underwater explosion underneath the water 100 miles north of Puerto Rico.
Ironically, just as the Atlantic was coming alive with U.S. naval vessels searching for the lost Thresher, a second test of the weapons that had finished off the sub occurred to the south of them, unnoticed and disregarded, even though seen and reported to the F.B.I. and the U.S. Coast Guard by a passing U.S. jetliner's pilot and crew, who observed the underwater explosion.

We thus can peg the development of these weapons by the Soviets as starting well before 1960, the first operational deployment of the gigantic strategic weaponry occurred in early 1963.

Note that the 1966 testing observed here is completely consistent with this estimated development schedule.

Thus large Soviet strategic scalar EM weapons have been operational on site for 24 YEARS !!!
This implies that at least three additional generations of the scalar EM weapons have been developed and deployed by now...