[DCBryan1]

Where , when , and what was the megaton amount ?

LOTS AND LOTS AND LOTS AND LOTS....Clicky linky for multi-megaton nuclear explosions

Number of electronics effected: zero.

[tentmaker]

Megaton level weapons aren’t good tests for EMP because anything over around 500 kilotons is a fusion based two stage device that uses a smaller fission bomb as a trigger. The smaller trigger device can saturate the atmosphere, leaving no additional electron cascade for the larger fusion bomb.

The only nuclear tests that qualify for EMP purposes are the Soviet “K” series tests over Kazakhstan in 1962. They are the only tests performed with the right kiloton range, the right altitude and over populated areas.
https://en.wikipedia.org/wiki/Soviet_Project_K_nuclear_tests

[Tilted Irish Kilt]

DCBryan1 :Where , when , and what was the megaton amount ?
LOTS AND LOTS AND LOTS AND LOTS....Clicky linky for multi-megaton nuclear explosions
www. https://www.youtube.com/watch?v=LLCF7vPanrY"

You sent me a 5:09 U-Tube video ( 3X faster ) of all " A Time-Lapse Map of Every Nuclear Explosion Since 1945 - by Isao Hashimoto"

That's fine film of nuclear detonations, but it doesn't answer the germain question of the electronic effects of High Altitude nuclear detonation .
None of those in the U-Tube film deal with "High Altitude" detonations, much less EMP effects , which is the essense of the question asked.
Thanks anyway !