Compression Connectors Demystified
by Ralph Parrett
Liberty AV Solutions' Director of Quality & Technical Services
Liberty Introduces our Universal C-Tec2 brand of Compression Connectors
We have a new design that features a ferrule-less connector for easy termination. This new design is much more forgiving of different company's cable manufacturing tolerances then our previous ConnecTec™ and CoaxMaster™ lines of connectors. Whether your cable is Liberty, Belden, Commscope, Coleman, General, or No-Name from who-knows-where - No problem! This new design will fit the cable and slide on much easier.
The biggest advantage of the ferrule-less design is the cable fit. The inner dimensions are very forgiving of cable deviations from different constructions. This makes these connectors Universal for many standard cable constructions. Single braid base band coaxial cable, dual foil and braid shield, Triple Foil-Braid-Foil shield, and everyone's favorite - Foil-Braid-Foil-Braid Quad shield cable are all served by one connector. This has the secondary advantage of reducing the number of connectors the installer needs. One Connector can replace up to 5 of the old ConnecTec designs. An example of this is CM-RG59M-RCA. It replaces CM-RG59C-RCA, CM-RG59U-RCA, CM-RG59PC-RCA, and CM-RG59P-RCA. This means an installer needs only one connector for all his RG59 cables instead of the previous four different part numbers. We maintained the same Tooling so there is no need to re-tool.
There are some disadvantages to a ferrule-less design. One is sacrificing a little performance. A ferrule-less design does not perform as well as a ferruled design. However you have to look at the limiting factor in the circuit before you say "No way!". If a ferruled connector has an SRL of -27dB @ 1000 MHz and the ferrule-less replacement has an SRL of -20dB @ 1000 MHz and the cable has an SRL of -17dB @ 1000 MHz - your weakest link is still the cable and there is no benefit to the higher performing connector. Another is the pull strength. The industry standard is 40 Lbs. Our previous ConnecTec line was warranted for 80Lbs+. This new ferrule-less design meets and exceeds the standard of 40 Lbs. In our testing we averaged 75 lbs + and we are very happy with those results. For those customers who must have the performance - No problem! We're going to keep some of the older products for those who must have them.
Introducing the players!
CM-RG6L-series with RCA, BNC, and F formats. This connector has an Orange colored silicone ring as an identifier. This is a Universal RG6 Non-Plenum Connector and will fit from single braid shield baseband video cable all the way up to Quad shield cables. It will also fit plenum cables too - from Dual Shield plenum all the way to Quad shield plenum.
CM-RG6M-series with RCA, BNC, and F and European IEC PAL Male and Female. This connector has a Purple colored silicone ring as an identifier. This is a Universal RG6 Plenum Connector and will fit from single braid shield baseband video cable all the way up to Quad shield cables. It will also fit non-plenum cables too - from single braid Shield to Tri-shield formats.
CM-RG59M-series with RCA, BNC, F, and European IEC PAL Male and Female. This connector has a Yellow colored silicone ring as an identifier. This is a Universal RG59 Connector and will fit all Plenum and Non-Plenum formats from single braid shield baseband video cable all the way up to Quad shield cables. It does not fit Head End Quad shield RG59 Silver Plated cables though. Those cables have two 90% plus coverage braid shields and they have very large diameters. CM-RG59Q-series are specifically engineered for Head End RG59 cables with the silver plated conductors.
We're re-naming our existing CM-RG11-series, CM-RG11P-series, CM-RGB25S-series, and CM-RGB23-series to the new C-Tec2 Branding. It is the same connector in all cases and here is a run down of these connector families:
CM-RG11-series with BNC and F formats. This connector has a Black colored silicone ring as an identifier. This is a Universal RG11 Non-Plenum Connector and will fit from single braid shield baseband video cable all the way up to Quad shield cables.
CM-RG11P-series with BNC and F formats. This connector has a White colored silicone ring as an identifier. This is a Universal RG11 Plenum Connector and will fit from single braid shield baseband video cable all the way up to Quad shield cables.
CM-RGB25S-series with BNC, RCA, and F formats. This connector has no color band at all. These are designed to fit Liberty's version of a 25 AWG solid center conductor Mini-High Resolution cable. The braid shield should be a serve shield and not a braided shield. The dielectric OD is between .072 to .079 inches and the cable OD is around .110 inches to fit correctly.
CM-RGB23-series with BNC, RCA, and F formats. This connector has a sky-blue color band as an identifier. This fits 23 and 25 AWG solid Mini-RG59 formats in dual shield. The dielectric diameter should be right around 0.100 inches and the cable OD around 0.159 inches to fit correctly.
A quick refresher on Compression Connectors is in order here.
Compression Connectors are popular because they bring speed to the installation. It takes less then 30 seconds to install Compression connectors whereas the crimp style connectors take about a minute each and solder style connectors about 2 minutes each from a much practiced installer.
Crimp BNC connectors have the edge in performance for exacting high frequency applications such as Serial Digital Broadcast. We recommend Broadcast quality true 75 Ohm BNC crimp plugs for SDI and SMPTE applications.
RCA connectors are used for much lower frequencies, typically below 10 MHz, so precision is not required and compression connectors outperform soldered connectors. Crimp style RCA plugs generally outperform solder and compression but do take 1-2 minutes to install if the installer is good.
An F connector function is coupling the cable to the receptacle and compression and crimp are relatively equal in performance and characteristics.