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Is there a solution for getting LC/PC for return loss more than 60 dB?  If it depends on final polishing film, is Ultimas final polishing film suitable? What kind of films will work?  Is there a special polishing method?



Unfortunately, there isn’t a special final film that produces 60 dB on UPC connectors. Our film is the most likely to get you there, but many other factors need to be considered including test leads on the RL meter.  However, I dare say getting 60 dB with a decent yield, may not be doable without considerable scrap.  Also, ultra-low return loss degrades with multiple mates, so you need to get it under the first test.  Consider that you may test -60.5 dB on the first test with ‘fresh’ test leads, but if the customer tests the next time with the best test leads, it may be -59 dB, then -57 dB, then finally settle somewhere below that. 

Here are a few additional comments:

  • In terms of polishing process, there’s not much more that can be done with current state of lapping films.
  • To tweak out the last few dB’s, you need to focus on core alignment (highest concentricity ferrules and fibers, and most precise adapter split-sleeves) that can be found.
  • RL values are not a characteristic of the connector itself, but of the mated pair.   A RL limit of 60 dB in production will mean you’ll need to constantly replacing test leads. The end user will likely not be able to correlate results.
  • If end user truly needs 60’s, APC’s are the way to go.


  Answered by AskFOC Technical Team April 24, 2017


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Kathleen Skelton

About Kathleen Skelton

Kathleen Skelton, Director of Strategic Marketing's experience includes management positions at Lightwave, KMI Research, PennWell Publishing, Beacon Communications, and Security Innovations, Inc. As a strategic marketing director, she utilizes her expertise in business development, online strategy, marketing planning, digital best practices, standard operating procedures development, and database design, management and training. Kathleen has global business and marketing experience. Outside of FOC, Kathleen is passionate about her volunteer work for several organizations and works with youth groups teaching business strategy for various community projects. In her volunteer work, Kathleen is committed to developing tomorrow's leaders through exciting, strategy-focused business education. This mission guides all of her work outside of the corporate office. Kathleen graduated from Curry College with a BA in Communications and Education and minors in English and Psychology. Kathleen resides outside of Boston, MA with her husband and four children. Follow @KATHLEENSKELTON