There is a band pass filter you can add for shooting over live fiber.  


From: Josh Luthman 
Sent: Wednesday, April 19, 2023 11:27 AM
To: AnimalFarm Microwave Users Group 
Subject: Re: [AFMUG] OTDR transmit power

On Calix optics they say it's OK if the OTDR hits it with 1650.  I don't think 
an OTDR will shoot if it sees 1310/1490.

On Wed, Apr 19, 2023 at 1:03 PM <dmmoff...@gmail.com> wrote:

  Oh I 100% believe they could do it.  If I knew tx power of the OTDR it would 
be easy to estimate how close they’d have to be to exceed the overload 
threshold of the transceiver.  

  “Dynamic Range” has to be a diff between Tx and sensitivity …..or so I would 
assume.  If it is then I could guess that maybe half the range is from Tx and 
half from Rx?  So a 50dB range might mean +25Tx?  I mean that all seems 
plausible to me, but it’s a lot of assuming.  I just wish this number was on 
the spec sheet.



  The alleged location of the case they were in was over 200,000 ft away.  A ZR 
is a bit sensitive, but that OTDR would have to be pretty damn strong to nuke 
it from that distance.  Maybe it is that strong, or maybe they’re lying to me.  
So a second part of the equation is whether I trust what this crew tells me in 
the future.  With same guys we had a link we were troubleshooting suddenly come 
up 20 minutes after they were “hands off”.  So I already think they might be 
compulsive bullshitters.





  From: AF <af-boun...@af.afmug.com> On Behalf Of Chuck McCown via AF
  Sent: Wednesday, April 19, 2023 11:57 AM
  To: AnimalFarm Microwave Users Group <af@af.afmug.com>
  Cc: ch...@go-mtc.com
  Subject: Re: [AFMUG] OTDR transmit power



  These guys think so:

  https://content.jwplatform.com/previews/IQitGvAV



  Best Regards,
  Chuck McCown

  McCown Technology Corporation 
  8401 N Commerce Dr
  Lake Point, Utah 84074
  801-250-9503 Office
  435-830-4306 Cell
  www.mccowntech.com
  www.microtrench.pro
  www.terabitnetworks.com



  From: dmmoff...@gmail.com 

  Sent: Wednesday, April 19, 2023 9:23 AM

  To: 'AnimalFarm Microwave Users Group' 

  Subject: [AFMUG] OTDR transmit power



  Does anyone know how strong the pulses from an OTDR might be?  Is there a 
rule of thumb to guess that based on the dynamic range?



  I’m trying to determine if a dark fiber provider might have blasted a ZR 
optic with an OTDR at close range.  We know they were out testing recently, and 
the manufacturer is saying receiver may have been overloaded and the link is 
way too long for the far end transceiver to have done it.



  I’m not out to blame anybody, this is just an educational exercise.


------------------------------------------------------------------------------

  -- 
  AF mailing list
  AF@af.afmug.com
  http://af.afmug.com/mailman/listinfo/af_af.afmug.com

  -- 
  AF mailing list
  AF@af.afmug.com
  http://af.afmug.com/mailman/listinfo/af_af.afmug.com



--------------------------------------------------------------------------------
-- 
AF mailing list
AF@af.afmug.com
http://af.afmug.com/mailman/listinfo/af_af.afmug.com
-- 
AF mailing list
AF@af.afmug.com
http://af.afmug.com/mailman/listinfo/af_af.afmug.com

Reply via email to