| It looks as if your customer ordered the DEFXS-AA. Contrary to most
published information, this modPMD has FC connectors. Our new SMF
modPMD, DEFXS-BA, has ST connectors. The following memo will ship
with the DEFXS-BA. It provides information on how to adapt FC to
ST connector types.
Please let me know if you need other assistance.
Dick Kirk
Network Product Support
The DEFXS-BA modPMD utilizes ST type single-mode optical fiber
receptacles. If a site installation has fiber optic cabling with
connectors other than the ST type, adapter cables, or re-termination
of the cables will be needed in order to connect the device to the
cable plant.
Any installation site that replaces a DEFXS-AA with a DEFXS-BA will be
faced with adapting between the FC connectors already in place in
the cable plant and the ST connectors in the new PMD.
This can be accomplished easily by obtaining fiber optic patch
cables with ST connectors on one end and FC connectors on the other
end. Simplex (one fiber) and Duplex (two fiber) cables are available.
An FC coupler is also needed to connect with the FC connector of
the cable plant.
Similar functionality can be achieved with hybrid connector adapters,
which utilize direct coupling between two connector types (ST and FC
in this case). A part is available directly from Digital -- part
number 12-44990-01.
The required items are available from quite a few sources. Several of
these are listed below.
There is a continued requirement for a minimum loss of 12 dB in the
SMF cable plant. Optical attenuators can be inserted in the cable plant
to assure that at at least 12 dB loss exists. Care must be taken when
adding attenuators to assure that the total link loss does not exceed
22 dB. The recommended method is to determine the actual loss of the
cable plant, and use the guidelines that follow.
Cable Plant Loss Attenuation Value to Add
0 to 5 dB 15 dB
5 to 10 dB 10 dB
10 to 12 dB 5 dB
> 12 dB 0 dB
These attenuators are available from several vendors. Some sources are
identified below.
SMF Adapter Cables:
Description: The adapter cable contains dispersion
unshifted single-mode optical fiber(s) and is terminated
on one end with an FC SMF connector and with an ST SMF
connector on the other end. Optical return loss of the
connectors shall be better that 20 dB.
Partial List of Vendors
3M/Fiber Optics Products
3M Telecom Markets Division
6801 River Place Boulevard
Austin, Texas 78726
Part Numbers:
ST to FC Jumper Cables
AENAM-AT0001 (1 meter)
AENAM-AT0003 (3 meter)
AENAM-AT0005 (5 meter)
Anixter Brothers
4711 Golf Road
Skokie, IL 60076 (708) 677-2600
Boston Office (508) 682-8870
Duplex FC to ST Jumper
FCST3 (3 meter)
FCST10 (10 meter)
Computer Crafts, Inc
Hawthorne, NJ
(201) 423-0405
Duplex ST to FC jumper
CCI/F4511107-01 (1 meter)
CCI/F4511107-03 (3 meter)
CCI/F4511107-05 (5 meter)
SMF Fiber Attenuators:
Partial List of Vendors
3M/Fiber Optics Products
3M Telecom Markets Division
6801 River Place Boulevard
Austin, Texas 78726
Attenuator:
FC Single-mode
8221 (5 dB)
8222 (10 dB)
8223 (15 dB)
Couplers:
FC to FC Single-mode
8210
Amphenol Corporation
1925 A Ohio Street
Lisle, OH 60532
(708) 960-1010
Single-mode In-line attenuators
6 to 10 dB
12 to 16 dB
Hybrid SMF Connector Adapters/Attenuators:
Hybrid connector adapters utilize direct coupling between two
connector types (ST and FC in this case). Attenuators can be
included in the adapter.
Partial List of Vendors
Storm Products Co
Advanced Technology Group
116 Shore Drive
Hinsdale, IL 60521
(708) 323-9398
SMF ST to FC Adaptor 71-S8-RP
SMF ST to ST Attenuators
5 dB 72-S8-RR-05-13
10 dB 72-S8-RR-10-13
15 dB 72-S8-RR-15-13
SMF FC to ST Attenuators
5 dB 72-S8-RP-05-13
10 dB 72-S8-RP-10-13
15 dB 72-S8-RP-15-13
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