Monthly Archives: May 2014

Question: What is the Difference Between SMA and Reverse Polarity SMA Connectors?

Tech Support: Reverse Polarity Connectors


(Image Comparing Standard and Reverse Polarity SMA)


Question:  What’s the difference between a regular SMA Connector and a Reverse Polarity SMA Connector?
In the late 1990’s, at the dawn of the WiFi technology boom that has inevitably changed the way we communicate, the Federal Communications Commission was greatly concerned.  Soon, wireless routers and access points would be entering the market and blasting the airwaves with short-distance transmissions that had never previously entered our airspace.  While these devices were designed to have a limited range, generally enough to cover a typical residence or office, the FCC knew that it was only a matter of time before users would attempt to boost the device’s range with amplifiers and/or external antennas, which could potentially wreak havoc on the WiFi band.
The FCC’s solution was a stop-gap measure known as Reverse Polarity Connectors.  For decades, SMA and TNC connectors have been used successfully for high-frequency applications, such as cell-phone networks.  The problem was that SMA’s and TNC’s were readily available on the market in the form of coaxial cable assemblies and antennas.  To prevent users from equipping their wireless routers with such accessories, the FCC mandated the WiFi manufacturers utilize a new type of connector on the back of their devices — The Reverse Polarity Connector. For a couple of years, this strategy worked, but eventually Reverse Polarity versions of SMA and TNC connectors, known as RP-SMA and RP-TNC respectively, became just as readily available as their regular counterparts.
So how do you tell which one is which?  A second look at the image above will help you.  An SMA Male Connector is shown on the left.  Notice that there is a pin sticking out of the center of the connector.  A Reverse Polarity SMA (RP-SMA) Connector is displayed on the right.  Notice that instead of a center pin, there is a center socket.  It is the swapping out of a center pin for a center socket that makes the connector a Reverse Polarity SMA (RP-SMA).  Note that both of the above connectors are considered male connectors.  Male SMA and Male RP-SMA connectors both feature their threads on the inside of the connector shell, i.e. they twist onto a female SMA or RP-SMA connector that feature their threads on the outside of the shell.  
You can never mix and match SMA and RP-SMA connectors because the pins and sockets will never actually make contact and allow the signal to pass thru.  At Amphenol Cables on Demand (, we will soon be offering a complete selection of Reverse Polarity SMA (RP-SMA) and Reverse Polarity TNC (RP-TNC)  Coaxial Cable Assemblies for use with your WiFi equipment.  Not sure which type you need?  If the RP-SMA does not look familiar, below is a comparison of a TNC and Reverse Polarity TNC (RP-TNC) connector for your reference:
(Pictured: RP-TNC on Left & TNC on Right)
Stay tuned for the official launch of our new RP-SMA and RP-TNC Coaxial Cable Assemblies in the weeks ahead at:
The Cable Guy PR Web Press Release Goes Live

Amphenol Cables on Demand Launches New Official Blog Website at to Help Answer Customer Cable Questions

Cables on Demand (, a division of Amphenol Corporation (NYSE:APH) and a leading online retailer of high-performance cables, connectors and accessories, has formally launched an official companion blog website at The technical-themed blog site aims to answer many of the most prevalent product-centric questions posed by the organization’s sizeable customer base in the U.S. and abroad.

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Cables on Demand Official Blog Website @

Our goal with is to empower individuals with knowledge; knowledge they can use to make an educated decision about their specific cabling needs.

Endicott, New York (PRWEB) May 02, 2014

Amphenol Cables on Demand (, an e-commerce subsidiary of one of the world’s largest cable and connector manufacturers, Amphenol, is excited to unveil a new dedicated blog website at The recently launched blog site follows a question and answer format, entitled “Ask the Cable Guy”, in which both customers and the public-at-large are welcomed to submit their respective questions regarding most any technical aspect of cable and connector products. Select questions will then be answered publicly on the blog website by “The Cable Guy”, a cabling technology aficionado with decades of relevant industry knowledge.

According to Amphenol Cables on Demand Product Manager, Nick Blas, the Cables on Demand Blog Site is first-and-foremost an educational resource for the public. “Throughout the years, we’ve observed certain product and technology questions tend to arise again and again. The fact that solutions to these questions appear to be utterly lacking on the web places prospective customers at a disadvantage. Our goal with is to empower these individuals with knowledge; knowledge they can use to make an educated decision about their specific cabling needs. In essence – CablesOnDemandBlog will act as a central repository of essential technical information that is difficult, if not impossible, to locate elsewhere.”

For those interested in submitting their own technical question(s) to “The Cable Guy” at, simply submit your question(s) via e-mail to: CablesOnDemandBlog(at)Gmail(dot)com. The Cable Guy will attempt to answer your question(s) as promptly as possible. Examples of current blog topics include:

10-Gigabit Ethernet Backbone Interface Options: Which One Should I Choose?

What’s the Difference Between 50-Ohm and 75-Ohm Coaxial Cable?

How Do I Know How Many Amps Your Cables will Handle?

Amphenol Corporation (NYSE:APH) is one of the industry’s largest manufacturers of connectors and cables worldwide, comprised of over fifty industry-leading divisions including Times Fiber Communications, Times Microwave Systems, Teradyne Connection Systems, Amphenol Interconnect Products and Amphenol RF. Since 1934, Amphenol Engineers have designed innovative interconnect solutions such as the BNC and UHF connector series, SKEWCLEAR wire technology, and XCede backplane architecture.

Amphenol Cables on Demand, launched in 2006, is Amphenol’s first wholly owned subsidiary optimized for the distribution of Amphenol brand cable products online. Based in Endicott, NY, Cables on Demand offers same day shipping before 3:00PM Eastern on over 3,000 unique cable SKUs. The company’s high product mix supports a vast array of applications including Network, Broadcast, Test, Instrumentation, Audio/Video, Data Storage, Clustered Computers, Prototyping, Automation, Industrial Control, Wi-Fi, Automotive and Avionics.