by Lee Kellett – guest blogger

In the spring of 2009, Corning Cable Systems announced that they would discontinue the production of the MT-RJ Unicam connector. Corning has stated that this was done because of low sales volume. Although they continue to offer a ‘bag of parts’, it has made some of us wonder if this might signal the beginning of the end for the somewhat maligned duplex connector.

When the MT-RJ was introduced by AMP in the late 1990s, it was touted as a low cost, easy to use workstation connector. After all, many liked the concept of the MT-RJ because of the large degree of comfort with a plug that looked like a copper-type RJ45. By May of 2000, AMP NETCONNECT announced that shipments of its popular MT-RJ fiber optic connector had surpassed the 2 million mark. This product was really taking off – but not without some issues. When giving his opinion about which SFF (small form factor) connectors will win, Jim Hayes from Fotec said, “The MT-RJ is another elegant design, but flawed …remember you have to make TWO perfect cleaves… it will be a factor, but not without teething problems.” Although many agreed with this thought, the connector showed it would have some legs.

By the early/mid 2000s, AMP NETCONNECT had granted approximately 30 licenses for others to manufacture the MT-RJ. Millions of connectors were being installed in data networks. The problem remained that this was not a high performance connector. Since the beginning, you were hard pressed to find someone who thought the MT-RJ was an overall better choice than the LC connector. The ‘feature’ of the 2 fiber ferrule proved too often be a detriment instead of a benefit. And, when it came to field installations – well, let’s just say – it was not always pretty. In 2005, Rodney Casteel at Commscope published an article:LC VERSUS MT-RJ CONNECTORS: WHICH IS THE BETTER PERFORMER – and concluded: “The classic one-fiber-at a-time approach of the LC connector, coupled with its tenability, makes it the right choice for the low loss, high performance SFF connector of the present and the future.”

As we approach the middle of 2010, is the data communications market ready to leave the MT-RJ behind? Some already think the end is here. Mike Hines, former VP at Ortronics tells me, “With increased data rates came dramatically reduced connection loss budgets…this exacerbated the practical issues associated with the MTRJ…less fault tolerance…then it was game over.” As far as Corning goes, they recently surveyed many of their customers who purchase the MT-RJ to make pre-terminated assemblies. They found that about 10% of connectors sold into that market were MT-RJs – keeping it in play for now. On the other side of that, Fiber Connections has seen a significant reduction in orders for the MT-RJ. When it is ordered, the patch cord most often has an MT-RJ on one end and an LC on the other.

Finding current information on the MT-RJ, beyond spec sheets and companies selling patch cords and such, is quite difficult. The reports and papers discussed here were from the late ’90s and early ‘00s. I found several other studies from that time period, including a case study by Methode Electronics (in 1999) about the connector relative to transceivers. Let’s just say that relative to the geometry differences of the LC and MT-RJ, the MT-RJ did not win in that study either.

The lack of more current published articles and press of any kind, support the idea that the end may be in sight. Nobody is talking about this product anymore (except for me, I guess). I did find something that may be as telling as any industry veteran’s opinion might be – an active RFQ to fiber a Navy base in Virginia. The project calls for MM cable with LC connectors at one end and MT-RJs at the workstation. My history with Military and Government optical communications projects has taught me that they are often far from the leading edge of technology. After all, many military projects were installing 100/140um fiber years after it was replaced with much better fiber options (50um and 62.5um). So, I’m no soothsayer, but I say yes, the industry is more than ready to move on.

Glorieux