continued from News....
On 5 December 1941, Paul E. Seaward, one of the U.S. Navy's highly trained radio cryptographers at Station H, intercepted Japanese naval air stations at Kanoya, Omura, and Yokosuka transmitting tactical radio messages to a radio call sign of 1 NI KU. Seaward instantly recognized Japanese call sign was bogus, and did not record the intercepts in the official Station H radio log. There is no Japanese tactical radio call sign of 1 NI KU listed in the December 1941 records of either Japan or the United States.
The Sitka radio traffic chief , Fred R. Thomson, discovered similar subterfuge. He also warned of radio deception, pointing out that the Japanese air station at Kasumigaura was using its own transmitter and sending radio messages to itself. Other monitor stations of the West Coast Communications Intelligence Network based at Seattle's Station SAIL issued similar warnings
Commander Jacobsen belittles Rochefort's intercept of 30 November 1941, in which the intelligence expert disclosed that the aircraft carrier Akagi, flagship of the Japanese Hawaii force, was in tactical radio communication with "several marus." On that date, the carrier and its group were in the north Pacific, midway toward Hawaii. According to official Japanese naval records, as well as those of U.S. Navy, the Akagi's task force was accompanied to Hawaii by several merchant tankers conscripted into naval service.
In the effort to bolster his discredited "radio silence doctrine," Commander Jacobsen misrepresented Admiral Isoroku Yamamoto's radio policy. On 25 November, the admiral issued a fleet radio communications policy that contained three provisos allowing fleet units to break radio silence:"1.Except in extreme emergency, the main force and its attached force will cease communicating. 2. Other forces are at the discretion of their respective commanders. 3. Supply ships, etc., will report directly to parties concerned."