327913-000 Tyco Electronics, 327913-000 Datasheet - Page 39

• Manufacturer Part Number: 327913-000
• Description: Connector Accessories Hexa Shield Adapter Aluminum Alloy Olive Drab
• Manufacturer: Tyco Electronics
• Type: Hexa Shield Adapterr

Catalog 1654025
Revised 12-04
www.tycoelectronics.com
Dimensions are in millimeters
and inches unless otherwise
specified. Values in brackets
are U.S. equivalents.
Electrical Interconnection System Design
Integrated Military Harness Systems for Defense and Allied Industries
Connector Accessories
Connector accessories,
such as Raychem adapters,
are available in many styles
and therefore their perform-
ance varies with construc-
tion. For a level of consis-
tency in performance it
is essential that, as with
connectors, a guarantee
in performance level be
achieved. Fittings not speci-
fied in this way may signifi-
cantly degrade the overall
system performance.
Branched
In addition to those compo-
nents described above,
branched harnesses
include transitions. This
type of harness is usually
made by hand and it is
therefore difficult to incorpo-
rate accurately made
machine fabricated shields.
The implications of this are:
Shields
Cable shields may be put
on by hand or by feeding
through a braiding machine.
However, as braid optimiza-
tion depends on all the con-
structional parameters of
the braid being accurately
specified, unless braid is
well constructed the shield-
ing performance can suffer
dramatically. Reductions in
shield performance of 20-40
dB have been measured on
badly made branched har-
nesses. The alternative
method is to use pull on
braids. If the cable bundle
diameter is known the braid
may be designed for opti-
mized performance.
Dimensions are shown for
reference purposes only.
Specifications subject
to change.
Transitions
Transitions, as with acces-
sories, are very susceptible
to performance variability
with construction type.
For high performance har-
nesses these components
should also have a guaran-
teed performance.
In general the use of tech-
niques such as hand sol-
dering or the use of butted
tape wraps are not recom-
mended except where only
a low performance of less
that 40dB is required.
Shielding Levels and
Component Performance
System Performance
To specify the overall
requirements of a complete
electronic system in terms
of its EMI characteristics it
is necessary to consider the
performance of the individ-
ual components parts. The
harnesses form one of the
major entry points for inter-
ference and this as such
can degrade a complete
system performance by a
significant amount. In gen-
eral terms, assuming that a
shielded harness system is
used, with the available
components on the market
the overall harness system
performance and typical
applications may be as
below.
I
I
I
I
I
40 to 50 dB Standard
shielded systems for
insensitive systems.
50 to 60 dB Military stan-
dard shielded systems for
general applications.
60 to 80 dB As above but
where full threat EMP &
TEMPEST protection is
required.
80 to 100 dB Severe
TEMPEST and very
sensitive systems.
Over 100 dB Exceptional
shielding requirements
only.
USA: 1-800-522-6752
Canada: 1-905-470-4425
Mexico: 01-800-733-8926
C. America: 52-55-5-729-0425
Shield performance is
specified in two ways,
either as a power relation-
ship in decibels (dB) or as
an absolute measurement
of the shield performance in
terms of the surface transfer
impedance. Except for very
specific low frequency
problems it is general to
specify the performance at
frequencies in the range
0.1MHz to 100MHz.
South America: 55-11-3611-1514
Japan: 81-44-900-5102
Singapore: 65-4866-151
UK: 44-1793-528171
(Continued)
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