The 5-3-3-5 and 9-5-5-9 Antennas

• Document Type: CREST
• Collection: NGA Records (Formerly NIMA)
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78T05439A000200220011-7
• Release Decision: RIPPUB
• Original Classification: T
• Document Page Count: 6
• Document Creation Date: December 28, 2016
• Document Release Date: April 26, 2001
• Sequence Number: 11
• Content Type: REPORT

ILLEGIB
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1 The 5-3-3-5 and 9-5-5-9 Antennas at Komsomolsk,
Khabarovsk, Tashkent and Tyura Tam ..............
Declassification Review by NIMA/DoD
25X2
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 TOP SECRET - EIDER - CHESS
sc-oo436-58
1. The 5-3-3-5 and 9-5-5-9 Antennas at Komsomolsk, Khabarovsk, Tashkent
aura Tam:
25X1 D
TALENT photography has revealed large ccxmu ications
facilities at Khabarovsk, Tashkent, Tyra Tam
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have antenna farms which include the usual rhombic antennas
plus unusual.
configurations of poles in a rectangular layout. For convenience these
rectangular arrangements are called 5-3-3-5 and 9-5-5-9 thus describing the
numbers of poles in each row as shown in Fig. 1.
5-3-3-5 9-5-5-9
Fig. 1.
While these antennas evidently are used for high-frequency radio
cn unications, their characteristics were not recognized immediately.
A subsequent survey of technical literature of both the USSR and the US
has revealed that these pole configurations (5-3-3-5 and 9-5-5-9) are
identical with the supporting structure of a form of travelling wave antennas
called "fishbone" in technical literature. The advantage of this type of
antenna is that it permits efficient, high-frequency operation employing short
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TOP SECRET - EIDER - CHESS
 TOP SECRET - EIDER - CHESS
SC-OO436-58
poles and requiring a minimum of land without sacrificing antenna .in or
band-width. Furthermore, since the antenna system uses short poles the cost
of the installation is moderate.
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the earliest being a. paper by Beverage and Peterson in the April 1931
O
Proceedings of the IRE. A photograph of a two-bay fishbone antenna
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operating in parallel as shown in Fig. 2.
Study of communications facilities revealed by TALENT photography
is cont nuing and a more comprehensive technical paper dealing with the
observe antenna systems will be published in the near future. (TOP SECRET CHESS)
(5-3-3-5 pattern) at the
A
Radio Antenna Engineering by Laport. A photograph of a model of the
two-bay fishbone antenna appears in Vestnik Svyazi, December, 1955. Ground
25X1 C photography was obtained of the two-bay antenna system near
Leningrad. Although photographs were not found in the open literature of
a four-bay "fishbone" antenna, a schematic diagram was found in which the
method of connecting the four bays to the transmission line is detailed.
The four-bay "fishbone" antenna (9-5-5-9 pattern) is two two-bay antennas
TOP SECRET - EIDER - CHESS
 TOP SECRET - EIDER - CHRS36-58
FOUR-BAY FISB ONE AH i
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FEED L32M
Fig. 2.
The `''fishbone" antenna is a high-frequency receiving antenna and ,is a
special form of a travelling verve antenna. It consists of a series of
dipoles arranged in collinear pairs, loosely coupled to a transmission line
at equal intervals by 1 capacitances. The tr n un(ssion line runs hori-
zontally in the direction of the inccning signal. The dipole elements are
short enough to be non-resonant within the frequency range of the array and are
spaced near enough together to provide a uniforma loading of the transmission line.
The dipoles are capacitively couple3 to the transmission line to keep the pro-
pagation velocity of the line above ninety percent of free space. The end of
the transmission line toward the trancmi tting station is texzai_nated in a non-
inductive resistance equal to the characteristic impedance of the line, which
is about 100 ohm
TOP SECRET - E DER- CHESS
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