A Japanese cavity magnetron before the Pacific War

How would the Pacific War change if Japan had a working cavity magnetron before 1935?

Japan could inflict more American losses and prolong the campaign, provided it used the six-year lead to manufacture enough operational radar sets.

A working cavity magnetron before 1935 would give Japan about six years to prepare for wartime production. The brief forecast is higher American losses and a somewhat longer Pacific campaign. A follow-up immediately asks how many units Japan could manufacture. The answer assumes that the six-year lead would allow production sufficient for Japanese needs by 1941, without estimating quantities or a revised course of the war.