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Note 903.5 DEFXS-BA and ST-type connectors 5 of 5
NPSS::KIRK 81 lines 10-MAR-1997 11:09
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The following mail entries should put this issue to rest. The ATT laser
uses a split sleeve alignment, which does allow some wiggling of the
ST connector. However, when the connector is allowed to rest in its
locked position, the laser/connector alignment is correct, and links
work.
Dick Kirk
Network Product Support
From: NPSS::KIRK "Dick Kirk DTN 226-7048" 7-MAR-1997 16:35:16.09
To: STKHLM::WEBJORN
CC: DELNI::ARIVERA,KIRK
Subj: DEFXS-BA connector recommendations and a question
Gullik,
I have some information regarding the ST connector recommended by ATT
(Lucent) for the laser on the DEFXS-BA. ATT has responded with
recommendations to use ST2 connectors made by ATT (Lucent), Molex,
Siecor, or AMP.
I also examined some of the lasers we have here. As I insert an ST
connector into the receptacle, there is little resistance to the
movement of the connector until the front edge of the body is
about 1 millimeter before the locking tabs. Some lateral freedom of
movement also is possible in this position. As the connector is
inserted further, resistance is noticeable. The ferrule reaches
the seated position when the front edge of the body is even with
the locking tabs. Pushing further compresses the spring so that the
body can be rotated to engage the locking tabs.
When I perform the same insertion with the same connector into
the HP receiver, resistance is noticed for the whole insertion
distance.
I believe that this resistance difference is due to the different
receptacle design between the laser and the receiver. The ATT Laser
has a split sleeve design in the receptacle. The HP receiver
has a solid receptacle sleeve. Resistance is not found in the
ATT receptacle until the ferrule enters the split sleeve area.
I think this explains why we feel some looseness of the connector
while inserting.
But I need to ask if a problem exists after the connector is fully
inserted and locked in place. If the links fail to get established,
then we need to examine how much optical power is coupled into the
single mode fiber. Do you have an optical power meter?
Regards,
Dick Kirk
From: STKHLM::WEBJORN "Gullik Webj�rn ( Gullik Webjorn ) Network advisory" 10-MAR-1997 04:35:31.94
To: NPSS::KIRK
CC: WEBJORN
Subj: RE: DEFXS-BA connector recommendations and a question
First, we have got our link up, using the patchcables supplied.
All links at the KTH Giga are 'loose', i.e. can be wiggled back
and forth, up and down. This does not seem to impair function.
There is indeed a dimensional mismatch, but as you say, the
AT & T transmitter device apparently does not care.
Our problems were in other areas, the cable network guys had
sent a attenuation report with wrong fiber ID's at one end.
This combined with a connector mismatch problem in the KTH
cable plant caused us several days til the link came up.
As it now looks, we are connected to the Internet backbone
with a 100 mb single mode fiber, and the link seems OK.
Regards,
Gullik
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