EXPERIMENTATION FOR TRANS-ATLANTIC TV BROADCAST
Document Type:
Collection:
Document Number (FOIA) /ESDN (CREST):
CIA-RDP78-01634R000300030066-4
Release Decision:
RIPPUB
Original Classification:
C
Document Page Count:
2
Document Creation Date:
November 17, 2016
Document Release Date:
April 13, 2000
Sequence Number:
66
Case Number:
Publication Date:
January 10, 1957
Content Type:
MF
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Body:
Approved For Release.2900/08/27: CIA-RD
OPERt TIOYS C0010IYATIM BOOM
Washington 25, D.C.
January 10, 1957
:rI1C ~.~TDtJ1 FOB.: Chairman, Committee on Broadcasting and Television (COBAT)
SUBJ2CT: ;xperimentatior_ for Trans-Atlantic TV Broadcast
1. This is with reference to your memorandum of n?ovember 16, 1956, on
the above subject requesting (1) a r engineering opinion concerring the pro-
nnosed Derveaux-Telecom trans--Atlantic TV s~rstem and (2) a recommendation
regarding; the advisability of investing perhaps $20, 000 to finance additional
experimentation and demonstrations with that equipment.
2. The technical problems in attempting to utilize the existing trans-
Att?.a.ntic telephone cable for the transmission of television signals involve
the development of an integrated system consisting o video pickup equipment,
video relay links, cable 'terminal equipment at both ends and equipment which
may be needed to convert the signals to other TV transmission standards.
From the technical information available,: it appears that the work which
has been done by the Derveaux firm has thus far been concentrated on the
development of video pickup and reproduction. equipment employing a special
t-;pe of scanning sys tem along or i-:.h pre-emphasis circuits intended to
produce a picture of higher qudity than would normally be expected with
the narrow bandtridths employed, Since this equipment is but a portion of
the complete system which would be required to relay TV programs over the
trans-Atlantic cable, it would be difficult, if not impossible, to predict,
on the basis of the information available, how satisfactory a picture would
result. Furthermore, it is not possible to determine whether the type of
scanning system used in the Derveaux system is the most satisfactory. It
is entirely possible that other scanning systems might prove more desirable
from the standpoint of compatibility with other elements in a complete
system and, at the same time, yield a more satisfactory picture with the
bandwidth limitations imposed by the use of the Mans-Atlantic cable.
3. It is believed that the magnitude of the time and cost which would
be required to develop to a satisfactory degree of perfection a complete TV
relay system utilizing the existing cable would be so great that it is diffi-
cult to understand how an investment of perhaps `;20,000.00 could contribute
very much toward the development of a complete relay system.
4. Trans-Atlantic TV will.., no doubt, some day become a reality but it
appears that a system of the type proposed could not be generall:T useful at
this time because of the limited amount of time the existing trans-Atlantic
cable could be made available. The cable is already heavily loaded with
telephone traffic, all of which would have to be discontinued during the
transmission of the TV signals. In this connection, it is pointed out that
the U.S. does not have exclusive rights in the use of all of the existing
cable capacity, certain channels of which are used, by agreement, by other
countries. Therefore, any arrangements to interrupt all of the telephone
circuits in order to permit the transmission of TV signals would require the
Approved For Release 2000/08/27 : CIA-RDP78-01634R000300030066-4
DOS & USIA declassification & release instructions on file
Approved For Relea 2000/08/27 : CIA-RDP78-01634R0003AO030066-4
approvkl of all countries which are parties to the agreement. This is
because the use of 150 kc bandwidth, which appears to be the value contemplated,
would occupy the total capacity of the existing telephone cable.
5. Because of the fact that US TV broadcast transmission standards
require 4,500 kilocycles for the video signal, there is serious doubt as to
whether the narrow bandwidth proposed would permit the transmission of a
picture which would be acceptable for viewing by the general public. In
comparison with a TV picture of normal quality in this country, the narrow
band TV picture of the type proposed would, because of basic physical laws,
be of poorer quality in one or more respects, Reducing the bandwidth of a
TV picture to the extent proposed can only be done at the expanse of reducing
picture detail, increasing the amount of flicker or reducing the ability to
reproduce rapid motion without blurring, or a comb =: .nation of these factor .
Because of its magnitude and complexity, it is believed that the eventual
development of a satisfactory trans.-Atlantic TV system, which may be based
on the use of either space radio or cables, will. require long range coordin-
ated efforts by the broad a 't L' dustry on an intern a.tiou '. scale and that
such development on -"-,,a pert of this coi:vrtt:y ,should b:: 2:t it., the hands of
that industry.
6. For the above reasons the TP23 does not r.:::c,j une..,a the investment of
any Federal funds is the Derveaux-Telecom system at this time.
7
T. H. E. A?esbitt
Chairman, Technical Panel for
International Broadcasting