INTELLIGENCE SUMMARY, 6 November, 1941
General.-Traffic volume slightly above normal. Receiving conditions
were fair, regular strong but heavy
static on night watches interfered somewhat.
Today the specific call-up on the Tokyo broadcast was eliminated. Formerly Tokyo radio called the
unit concerned when the dispatch was
addressed to a member of that unit. Beginning yesterday afternoon all broadcast messages are
addressed to a single call without regard
to the addressee of the message. The recovery of the radio organization will be hampered by this new
advance in Communication Security.
Moreover there were nine messages today on this broadcast from which the address and originator were
missing. This may be the start of complete
elimination of headings on broadcast circuits. Tokyo addressed a WIWI message to the Chiefs of Staff of the
Combined Fleet and Submarine Force.
Takao-Bako Area.-It is now certain that there is a very heavy air concentration on Taiwan. This comprises practically
the entire Combined Air Force including
the Commander and his staff plus at least one carrier division and an unknown amount of the fleet air arm. No additional units of the Third Fleet were
located there today but it is believed
that CinC Third Fleet is now en route BAKO from SASEBO. From traffic association it is believed that some
Second Fleet units are in Takao area
but this has not yet been proven. The South China Fleet Command has been active in dispatches to
Combined Fleet.-A large amount of Combined Fleet traffic is now appearing with secret (tactical) calls in
Mandates.-The Mandates traffic has dropped off somewhat. The Sixth Defense Force at Truk and the RNO PALOA
continue to be the most active units.
(FROM: U.S. CONGRESS JOINT COMMITTEE ON PEARL HARBOR
ATTACK HEARINGS; PT. 35, THE CLAUSEN
INVESTIGATION, PP. 62-81. EXHIBIT "A" DAILY COMMUNICATION