Patent Publication Number: US-2015064946-A1

Title: Radio frequency subscriber drop equipment having high voltage protection circuits and related contact assemblies

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application claims priority under 35 U.S.C. §119 to U.S. Provisional Application Ser. No. 61/871,925, filed Aug. 30, 2013, the entire content of which is incorporated by reference herein. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to cable television networks and, more particularly, to radio frequency (“RF”) subscriber drop equipment that is suitable for use in cable television networks. 
     BACKGROUND 
     A coaxial cable is a known type of communications cable that may be used to carry radio frequency (“RF”) signals. Coaxial cables are widely used as transmission lines in cable television networks that provide cable television service, broadband Internet connectivity and Voice-over-Internet Protocol (“VoIP”) telephone service to a plurality of subscribers. Coaxial cables are also used in a wide variety of other applications such as, for example, interconnecting electrical equipment, connecting electrical equipment to antennas and various other applications.  FIG. 1  is a perspective view of a conventional coaxial cable  10  that has been partially cut apart to reveal its internal structure. As shown in  FIG. 1 , the coaxial cable  10  has a central conductor  12  that is surrounded by a dielectric insulator  14 . A tape  16  may be bonded to the outside surface of the dielectric insulator  14 . A metallic electrical shield  18  such as braided shielding wires surrounds the central conductor  12 , dielectric insulator  14  and tape  16 . One or more electrical shielding tapes (not shown in  FIG. 1 ) may surround the metallic electrical shield  18 . The central conductor  12 , dielectric insulator  14 , tape  16 , electrical shield  18  and any electrical shielding tape are enclosed within a protective cable jacket  20 . 
     The central conductor  12  of coaxial cable  10  may comprise, for example, a copper wire or a copper clad aluminum or steel wire. The central conductor  12  is designed to carry RF signals. Typically, a conductor such as central conductor  12  that carries RF or other high frequency signals acts as an antenna, and thus some of the signal energy is radiated from the conductor, resulting in signal loss or “attenuation.” Coaxial cables are designed to reduce such signal attenuation by positioning the electrical shield  18  (which is connected to a ground reference) around the central conductor  12 . As a result of this arrangement, the electromagnetic field of the RF signal that is carried by the central conductor  12  is generally trapped in the space inside the electrical shield  18 , thereby greatly reducing signal radiation and associated signal attenuation losses. 
     Typically, each end of a coaxial cable is terminated with a male coaxial connector. The most common type of coaxial connectors are referred to in the art as “F-style” coaxial connectors. Female F-style coaxial connectors, which are often referred to as “connector ports” are commonly mounted on wall plates in homes and on various devices such as televisions, cable modems, splitters, signal amplifiers, tap units, ground blocks, etc. A typical female F-style connector port comprises an externally threaded cylindrical housing that includes an aperture on one end thereof that is configured to receive a protruding central conductor of a male F-style coaxial connector. A typical male F-style coaxial connector includes an internally-threaded nut which is threaded onto the externally-threaded housing of the female F-style coaxial connector port. A coaxial cable that includes a coaxial connector on at least one end thereof is referred to herein as a “terminated coaxial cable.” Terminated coaxial cables are used in a wide variety of applications including use as jumper cables, internal cabling within buildings, drop cables and the like. 
       FIG. 2  is a perspective view of a conventional male F-style coaxial connector  30 .  FIG. 3  is a side cross-sectional view of the male F-style coaxial connector  30  of  FIG. 2 .  FIG. 4  illustrates the connector  30  of  FIGS. 2-3  after it has been attached to an end of a coaxial cable  10  to produce a terminated coaxial cable. 
     As shown in  FIGS. 2-4 , the F-style coaxial connector  30  includes a tubular connector body  32 , a contact post  34 , a compression sleeve  36  and an internally-threaded nut  38 . In  FIG. 2 , the compression sleeve  36  is depicted in its “unseated” position in which it may receive a coaxial cable  10  that is to be terminated into the coaxial connector  30 . 
     When the compression sleeve  36  of coaxial connector  30  is in its unseated position of  FIG. 2 , a coaxial cable such as cable  10  may be inserted axially into the compression sleeve  36  and the connector body  32 . The central conductor  12 , dielectric insulator  14  and tape  16  of cable  10  (the coaxial cable  10  is not depicted in  FIGS. 2-3  to more clearly show the structure of the connector  30 ) are inserted axially into the inside diameter of the contact post  34 , while the electrical shield  18 , and the cable jacket  20  are inserted inside the tubular connector body  32  so as to circumferentially surround the outer surface of the contact post  34 . The outside surface of the contact post  34  may include one or more serrations, teeth, lips or other retention structures  35  (see  FIG. 3 ). Once the coaxial cable  10  is inserted into the coaxial connector  30  as described above, a compression tool may be used to forcibly axially insert the compression sleeve  36  further into the tubular connector body  32  into its “seated” position (see  FIG. 4 ). Moving the compression sleeve  36  into its seated position decreases the radial gap between the tubular connector body  32  and the contact post  34  so as to radially impart a generally 360-degree circumferential compression force on the electrical shield  18  and the cable jacket  20  that circumferentially surround the outer surface of contact post  34 . This compression, in conjunction with the retention structures  35  on the outside surface of the contact post  34 , applies a retention force to the coaxial cable  10  that firmly holds the coaxial cable  10  within the coaxial connector  30 . As shown in  FIG. 4 , the central conductor  12  of the coaxial cable  10  extends into the internal cavity of the internally-threaded nut  38  to serve as the male protrusion of the coaxial connector  30 . 
     As noted above, male F-style coaxial connectors such as connector  30  are used to mechanically and electrically attach a coaxial cable such as coaxial cable  10  to a female connector port. A wide variety of RF subscriber drop units such as splitters and directional couplers, signal amplifiers, tap units, inline filters and the like include female connector ports and are connected to other RF subscriber drop units via coaxial cables that have F-style coaxial connectors on either end thereof. For example, a 1×2 RF splitter has a first female connector port that acts as an input port and second and third female connector ports that act as first and second output ports. First through third coaxial cables, each of which is terminated with an F-style coaxial connector, may be connected to the respective first through third female connector ports. Electronic circuit elements are typically mounted on a printed circuit board within the RF splitter to divide the signals input through the input port and deliver the splits signals to the output ports.  FIG. 5  is a perspective view of a conventional F-style female connector port  40  that is widely used on RF splitters, ground blocks, amplifiers, and the like.  FIG. 6  illustrates a conventional coaxial cable splitter  50  having the female connector ports  40  of  FIG. 5 . 
     As shown in  FIG. 5 , the female connector port  40  may comprise a cylindrical housing  41  that has a plurality of external threads  42 . The distal face  44  of the cylindrical housing  41  includes an aperture  46 . A central conductor  48  (barely visible in  FIG. 5 ) runs longitudinally through the center of the female connector port  40 . The internally-threaded nut  38  of a mating male F-style coaxial connector  30  is inserted over, and threaded onto, the external threads  42  of the female connector port  40  so that the central conductor  12  of the coaxial cable  10  that is attached to the coaxial connector  30  is received within the aperture  46 . The central conductor  48  of female connector port  40  is configured to receive the central conductor  12  of the mating male F-style coaxial connector  30 , thereby electrically connecting the central conductors  12 ,  48 . Once the internally-threaded nut  38  is fully threaded onto the external threads  42  of the female connector port  40 , the distal face  44  of the female connector port  40  is brought into mechanical and electrical contact with the base  34   b  ( FIG. 3 ) of the contact post  34 , thereby providing a ground plane connection between the body assembly  32  of coaxial connector  30  and the housing  41  of the female connector port  40 . 
     When summoned to fix a problem with a cable television subscriber&#39;s service, technicians may not take the time to trouble-shoot various connections associated with a drop. Instead, the technicians may cut the F-style coaxial connectors off of the coaxial cables and throw away any splitters, couplers, or other devices. Unfortunately, this practice increases costs to cable television service providers. Moreover, this practice is wasteful in many cases because otherwise good connectors and/or devices are being thrown away. Additionally, RF subscriber drop units may be subject to damage from high transient voltages that may be passed from the coaxial cables into the RF subscriber drop units. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings illustrate various embodiments of the present invention. The drawings and description together serve to fully explain embodiments of the present invention. 
         FIG. 1  is a perspective view of a conventional coaxial cable that has been partially cut apart. 
         FIG. 2  is a perspective view of a conventional male F-style coaxial connector that has a compression style back fitting with the compression sleeve thereof in an unseated position. 
         FIG. 3  is a longitudinal cross-sectional view of the conventional F-style coaxial connector of  FIG. 2 . 
         FIG. 4  is a perspective view of the conventional F-style coaxial connector of  FIG. 2  mounted on a coaxial cable to provide a terminated coaxial cable. 
         FIG. 5  is a perspective view of a conventional female connector port. 
         FIG. 6  is a perspective view of a conventional 1×2 RF splitter that utilizes the female connector ports of  FIG. 5 . 
         FIG. 7A  is a partially-exploded perspective view of an RF subscriber drop unit according to embodiments of the present invention with the cover thereof removed. 
         FIG. 7B  is a bottom, partially-exploded view of the RF subscriber drop unit of  FIG. 7A . 
         FIG. 7C  is a side, partially-exploded view of the RF subscriber drop unit of  FIG. 7A . 
         FIG. 7D  is a cross-sectional view taken along the line  7 D- 7 D of  FIG. 7C . 
         FIG. 7E  is an enlarged view of the callout labeled “B” in  FIG. 7D . 
         FIG. 7F  is an enlarged view of the callout labeled “C” in  FIG. 7A . 
         FIG. 8A  is a perspective view of a contact assembly that is included in the connector ports of the RF subscriber drop unit of  FIGS. 7A-7F . 
         FIG. 8B  is a bottom view of the contact assembly of  FIG. 8A . 
         FIG. 8C  is a side view of the contact assembly of  FIG. 8A . 
         FIG. 8D  is a side, cross-sectional view taken along the line  8 D- 8 D of  FIG. 8C . 
         FIG. 8E  is an exploded perspective view of the contact assembly of  FIG. 8A . 
         FIG. 8F  is an exploded, cross-sectional view of the contact assembly of  FIG. 8A . 
         FIG. 9  is an enlarged, bottom view illustrating the contact tail of the contact assembly of  FIG. 8A  extending through the aperture in the conductive spark gap unit included in the contact assembly. 
         FIG. 10  is a section view of the RF subscriber drop unit of  FIGS. 7-8  illustrating how a coaxial cable may be terminated into one of the connector ports thereof. 
     
    
    
     DETAILED DESCRIPTION 
     Pursuant to embodiments of the present invention, RF subscriber drop equipment such as RF splitters, directional couplers, tap units, signal amplifiers, inline filters and the like are provided that have connector ports that each have conductive spark gap units that surround the contact tail of a spring contact structure of the connector port. In some embodiments, the spring contact may be mounted in a contact assembly. The contact tail may comprise a flat strip of conductive material. The conductive spark gap unit has an opening therethrough. The contact tail may be inserted through the opening in the conductive spark gap unit so that edges of the contact tail are in close proximity to the edge(s) of the conductive spark gap unit that define the opening therethrough. When a sufficiently high voltage is imparted to the spring contact, current may arc from the contact tail to an edge of the conductive spark gap unit that is in close proximity to the contact tail. The spark gap ring may be electrically connected to a grounded housing of the RF subscriber drop unit and may therefore discharge the high voltage to ground. 
     In some embodiments, the conductive spark gap unit may include a hollowed-out protrusion. The opening through the conductive spark gap unit may be at the bottom of the protrusion. A moisture seal such as, for example, an insulative disk that has an aperture therethrough may extend through the hollowed-out protrusion of the conductive spark gap unit. The contact tail may be inserted through the aperture in the moisture seal. The aperture through the moisture seal may have a cross-section that substantially matches a cross-section of the contact tail, and the aperture may have a cross-section that is slightly smaller than the cross-section of the contact tail so that the insulative disk may form a moisture-resistant seal that may reduce or prevent ingress of water or moisture that may migrate through the connector port into the interior of the housing of the RF subscriber drop unit. 
     In some embodiments, one or more of the connector ports on the RF subscriber drop units according to embodiments of the present invention may comprise “integrated” compression style connector ports that are configured to have a coaxial cable compression terminated therein. Integrated compression style connector ports are known in the art and have been used with RF subscriber drop equipment. An example integrated compression style connector port is disclosed in U.S. Patent Publication No. 2013/0157507, assigned to the assignee of the present application. The use of integrated compression style connectors may have several advantages, including making it more difficult for unauthorized users to access the RF subscriber drop unit and eliminating the problem of F-style coaxial connectors that are not sufficiently tightened onto their mating female connector port (which can result in signal loss, loss of the ground plane connection, ingress of unwanted RF interference, etc.). In such embodiments, the conductive spark gap unit may, for example, be interposed between the contact assembly and the housing of the RF subscriber drop unit so as to be in electrical contact with the housing. 
     Embodiments of the present invention will now be described in greater detail with respect to  FIGS. 7-10 , in which example embodiments of the invention are shown. 
     An RF subscriber drop unit  100  according to a first embodiment of the present invention is illustrated in  FIGS. 7-9 . In particular,  FIG. 7A  is a perspective view of the RF subscriber drop unit  100  with a cover plate thereof removed to reveal the interior of the unit.  FIGS. 7B and 7C  are a bottom view and a side view, respectively, of the RF subscriber drop unit  100  (with the cover omitted).  FIG. 7D  is a cross-sectional view of the RF subscriber drop unit  100  taken along the line  7 D- 7 D of  FIG. 7C .  FIG. 7E  is an enlarged view of the portion of the cross-sectional view of  FIG. 7D  that is within the call-out labeled B in  FIG. 7D .  FIG. 7F  is an enlarged view of the callout labeled C in  FIG. 7A . 
       FIGS. 8A-8F  illustrate a contact assembly that is included in each of the connector ports of the RF subscriber drop unit of  FIGS. 7A-7E . In particular,  FIG. 8A  is a perspective view of the contact assembly.  FIG. 8B  is an end view of the contact assembly.  FIG. 8C  is a top view of the contact assembly that illustrates the position of the spring contact within the contact assembly using dotted lines.  FIG. 8D  is a cross-sectional view of the contact assembly taken along the line  8 D- 8 D of  FIG. 8C .  FIG. 8E  is an exploded perspective view of the contact assembly that illustrates how the individual components thereof may be put together to form the contact assembly.  FIG. 8F  is an exploded, cross-sectional view of the contact assembly of  FIG. 8A . 
     As shown in  FIGS. 7A-7D , the RF subscriber drop unit  100  has a housing  102  with opposite first and second sides  102   a,    102   b.  As noted above, a cover piece of the housing is removed to illustrate the interior  102   i  thereof. A printed circuit board  104  ( FIGS. 7A-7B ) is mounted within the interior  102   i  of housing  102  on a plurality of posts  106  that extend downwardly from the inner surface of the top wall of the housing. Circuitry (not shown) is provided on the printed circuit board  104 . 
     An input connector port  110 - 1  extends from side  102   a  of housing  102 , and a pair of output connector ports  110 - 2 ,  110 - 3  extend from side  102   b  of housing  102 . The above-mentioned circuitry on the printed circuit board  104  electrically connects connector port  110 - 1  with connector ports  110 - 2 ,  110 - 3 . The printed circuit board  104  performs various functions (depending on the type of device) as would be known to one skilled in the art. Each connector port  110  is configured to be electrically and mechanically attached to a prepared end of a respective coaxial cable. 
     As shown best in  FIG. 7E , each connector port  110  has a tubular connector body  112  having a base  112   a  and an opposite distal end  112   b.  The connector body  112  of each connector port  110  may be formed integrally with the housing  102 . The housing  102  including the connector bodies  112  may be formed of a conductive metal such as, for example, brass, steel, or bronze, or alloys thereof or another metal or metal alloy. The inner and/or outer diameters of the connector body  112  may vary along the length of the connector body  112 . 
     The connector port  110  also includes a compression element  114  that is coupled to the distal end  112   b  of the connector body  112 . The compression element  114  is configured to move between an unseated position and a seated position (shown in its seated position in  FIG. 7E ). The compression element  114  is configured to impart a compressive force to secure one or more elements of a coaxial cable within the connector body  112  when the compression element  114  is in the seated position. As shown in  FIGS. 7A-7B , the compression element  114  may be detachable from the connector body  112  to allow an installer a better view of the interior of the connector port  110  when a coaxial cable  10  is installed into the connector port  110 . 
     The connector port  110  further includes a tubular, open-ended inner contact post  120  that is positioned within the connector body  112 . The contact post  120  has an axial bore  134  that is open at either end thereof. An installer may insert the central conductor  12 , dielectric insulator,  14  and tape  16  of a coaxial cable  10  within the contact post  120 . The electrical shield  18  of the coaxial cable  10  may be inserted to concentrically surround the contact post  120  (the end portion of the jacket  20  may be at least partially removed). The outside surface of the distal end of the contact post  120  may include one or more serrations, teeth, lips or other structures  122 . The contact post  120  is typically formed of a conductive material such as, for example, brass, steel, or bronze, or alloys thereof. 
     The compression element  114  may comprise a hollow cylindrical body that may be permanently or detachably attached to the connector body  112 . The compression element  114  is typically formed of a non-conductive, plastic material, but may also be formed of other materials. In some embodiments, the portion of the compression element  114  that is received within the connector body  112  may have a first external diameter that is less than a second external diameter of the opposite end of the compression element  114 . A gasket or O-ring  115  may be mounted on the exterior surface of the compression element  114 . As shown best in  FIG. 7E , the inner diameter of the end of the compression element  114  that is received within the connector body  112  may be greater than the inner diameter of the opposite end of the compression element  114 . A ramped transition section may connect these inner radii. While the compression element is depicted as an “internal” compression element in the embodiment of  FIG. 7 , it will be appreciated that in other embodiments an “external” compression element may be used that fits over the outside surface of the connector body  112 . 
     The compression element  114  is closer to the apparatus housing  102  when in the seated position than when in the unseated position. In addition, the compression element  114  is positioned between the connector body  112  and the contact post  120  when in the seated position. The outer surface of the compression element  114  may include a groove therein (not shown) that is configured to receive a gripping element of a compression tool that is used to move the compression element  114  from the unseated position to the seated position. 
     Still referring to  FIG. 7E , the connector  110  includes a contact assembly  140  that is positioned within the connector body  112  between the base of the contact post  120  and the side wall  102   a  or  102   b  of the housing  102 . The contact assembly  140  mounts a spring contact  150  within the connector port  110 . The spring contact  150  receives and makes electrical contact with a center conductor  12  of a coaxial cable  10  that is terminated into connector port  110  in order to electrically connect the center conductor  12  to circuitry on the printed circuit board  104 . 
     Turning now to  FIGS. 8A-8E , the contact assembly  140  and spring contact  150  are illustrated in greater detail. As shown in  FIGS. 8A-8E , the contact assembly includes an upper insulative housing  142  and a lower insulative housing  144  that is mounted adjacent to the upper insulative housing  142 . Each of the upper insulative housing  142  and the lower insulative housing  144  have respective bores therethrough. The spring contact  150  is received within these bores. 
     The spring contact  150  has a base  152  and a pair of cantilevered arms  154 ,  156  that extend forwardly from the base  152 . Each of the cantilevered arms  154 ,  156  is flared at its distal end and then is folded back on itself. The folded back sections of the cantilevered arms  154 ,  156  may contact each other. The center conductor  12  of a coaxial cable  10  that mates with connector port  110  may be received between the flared portions of the cantilevered arms  154 ,  156 . A contact tail  158  extends rearwardly from the base so as to extend through the lower insulative housing  144 . The contact tail  158  comprises the portion of the spring contact  150  that is opposite a spring contact portion  154 ,  156  that engages the center conductor of a mating coaxial cable. The contact tail  158  also comprises the portion of the spring contact  150  that extends from the connector port  110  into the interior  102   i  of the housing  102  of the RF subscriber drop unit  100 . 
     The spring contact  150  may have various shapes and configurations. The spring contact  150  may be formed as an integral piece and may be formed of a conductive metal such as, for example, brass, steel or bronze or alloys thereof or another metal or metal alloy. In some embodiments, the spring contact  150  may be formed of a resilient metal such as beryllium copper or phosphor bronze. 
     A conductive spark gap unit  170  is also provided as part of the contact assembly  140 . The conductive spark gap unit  170  in the illustrated embodiment comprises a metal disk  172  that has a hollow protrusion  174  extending from a front surface thereof. A spark gap aperture  176  is provided at the distal end of the hollow protrusion  174 . A moisture seal  180  in the form of, for example, an insulating disk  180  may be positioned within the hollow protrusion  174 . In some embodiments, the hollow protrusion  174  may take the form of a truncated frusto-conical protrusion that projects from a surface of the metal disk  172 . The insulating disk  180  may have an aperture  182  through a central portion thereof. The aperture  182  may have a cross-sectional shape that matches the cross-sectional shape of the contact tail  158  and that is slightly smaller than the cross-section of the contact tail  158 . The contact tail  158  may be inserted through the aperture  182  of insulating disk  180  and through the spark gap aperture  176  of the conductive spark gap unit  170 . The insulating disk  180  may provide a moisture-resistant seal to prevent moisture that is received through the bores in the insulative housings  142 ,  144  from migrating through the aperture  176  in the conductive spark gap unit  170  into the interior  102   i  of housing  102 . 
     The conductive spark gap unit  170  may act to discharge a high voltage that is passed from coaxial cable  10  to connector port  110  to ground. Such a high voltage may be injected onto the coaxial cable by, for example, a lightning strike. As shown in  FIGS. 8A-8E , the contact tail  158  extends through the aperture  176  in the conductive spark gap unit  170 . The contact tail  158  does not physically contact the conductive spark gap unit  170 , but the four corners of the cross-section of the contact tail  158  may be in close proximity to the edge of the metal cap at the distal end of the hollow protrusion that defines the aperture  176 . 
     For example,  FIG. 9  is an enlarged bottom cross-sectional view of the contact assembly  140  taken across the aperture  176  in the conductive cap  178  at the bottom of the hollow protrusion  174 . As shown in  FIG. 9 , the diameter of the aperture  176  determines the distance of the edges of the contact tail  158  from the conductive cap  178 . The minimum distance between the edges of the contact tail  158  and the conductive cap  178  can be set so that, at a predetermined voltage level (e.g., voltages above approximately 50 volts), the current carried on the spring contact  150  will arc from the contact tail  158  to the conductive cap  178 . It will be appreciated that the aperture  176  may be other than a circular cross-section and/or that the contact tail  158  may have other than a rectangular cross-section. 
     As shown, for example, in  FIG. 7E , the conductive spark gap unit  170  is in physical and electrical contact with the housing  102 . The housing  102  may be grounded to, for example, earth ground via a conventional grounding wire. As the current arcs to the spark gap ring it is carried to earth ground via the housing  102 , thereby discharging the transient voltage spike so that it does not pass to the sensitive electronic circuits on the printed circuit board  104  which can be damaged or destroyed by such transient voltage spikes. 
     In the depicted embodiment, the contact tail  158  is closest to the conductive spark gap unit  170  at four separate points, which are at the corners labeled  179  in  FIG. 9 . Thus, when a transient high voltage spike passes through the contact tail  158 , the current may tend to arc from the contact tail  150  to the conductive spark gap unit  170  at one of these four locations. When such a high current level arcs across a gap, it may damage the metal such that it may not support a current arc if another high voltage spike is passed to the contact tail  158 . By providing four locations  179  where the contact tail  158  passes close to the conductive cap  179 , the connector port  110  may be designed to survive at least four separate high voltage spikes. 
     The connector port  110  may be assembled by putting together the components of the contact assembly  140  in the manner shown in the exploded perspective view of  FIG. 8E . The contact assembly  140  may then be inserted into the cavity defined by the connector body  112 . The sidewall  102   a  of the housing  102  may have a circular port aperture  108  (see  FIG. 7F ) that mates with the hollow protrusion  174  of the conductive spark gap unit  170 . The contact tail  158  may protrude through this port aperture  108  into the interior  102   i  of the housing  102 . A wire or other contact structure  105  may electrically connect the contact tail  158  to the printed circuit board  104 . The contact tail  158  may include an aperture and the wire  105  may be received within this aperture in the contact tail  158 . 
     After the contact assembly  140  (including the conductive spark gap unit  170 ) is inserted into the interior of the connector body  112 , the contact post  120  may then be inserted within the interior of the connector body  112  in order to lock the contact assembly  140  in place. As shown in  FIG. 8E , the distal end of the upper insulator  142  of the contact assembly  140  is received within the base of the contact post  120 . The contact post  120  may have a diameter that is slightly larger than the internal diameter of the portion of the cavity in the connector body  112  that receives the contact post  120  so that the contact post  120  is interference fit within the cavity. The contact post  120  presses the upper and lower insulators  142 ,  144  against the conductive spark gap unit  170 , thereby forcing the conductive spark gap unit  170  against the exterior of the housing  102  to electrically connect the conductive spark gap ring  170  to the housing  102 . In this fashion, the interference fit of the contact post  120  within the connector body  112  acts to hold the contact assembly  140  (including the conductive spark gap unit  170 ) in place within the connector body  112  and also acts to electrically connect the conductive spark gap unit  170  to ground through the housing  102 . 
     As shown best in  FIGS. 8A ,  8 B and  8 E, the hollow protrusion  174  of the conductive spark gap unit  170  may not be located in the center of the metal disk  172 , but instead may be offset to one side of the metal disk  172 . The hollow protrusion  174  may be offset in this fashion in order to ensure that the contact tail  158  is oriented properly with respect to the printed circuit board  104 . This arrangement may make it easier to solder the wire or other contact structure  105  to the printed circuit board  104 . As shown in  FIGS. 7E and 8A , each conductive spark gap unit  170  having the hollow protrusion  174  resides in the bottom potion of a respective one of the connector ports  110 . The circular port apertures  108  through the sidewalls of the housing  102  may be offset from respective central axes of the connector ports  110  so that they are aligned with the offset hollow protrusions  174 . 
       FIG. 10  is a section view of the RF subscriber drop unit  100  of  FIGS. 7-8  illustrating how a coaxial cable  10  may be terminated into one of the connector ports  110  thereof. Before the cable  10  is inserted into the connector port  110 , end portions of the dielectric  14 , the tape  16 , the electrical shield  18  and the cable jacket  20  are cut off and removed so that the end portion of the central conductor  12  is fully exposed, as described above with respect to  FIG. 1 . Additional end portions of the cable jacket  20  and any electrical shielding tape are then removed to expose an end portion of the wires of the electrical shield  18 . Next, the central conductor  12 , dielectric  14 , and the tape  16  of cable  10  are axially inserted through the compression element  114  and into the axial bore of the contact post  120 , while the exposed electrical shield  18  is inserted through the compression element  114  and over the outside surface of the contact post  120 . The exposed length of the central conductor  12  is sufficient such that it will pass all the way through the connector body  112  and extend into contact assembly  140  where it is received between the cantilevered arms  154 ,  156  of the spring contact  150 . 
     The exposed end portions of the wires of the electrical shield  18  reside in a front portion of the generally annular cavity between the contact post  120  and the connector body  112 , thereby placing the electrical shield  18  in mechanical and electrical contact with at least one of the connector body  118  or the contact post  120 . The center conductor  12  of the coaxial cable  10  is electrically connected to a circuit on the printed circuit board  104  via the spring contact  150 , since the tail  158  of spring contact  150  extends into the interior of the housing  102   i  where it is electrically connected to the printed circuit board  104 , as is shown in  FIG. 7F . An installer then uses a compression tool to move the compression element  114  into its seated position after the coaxial cable  10  has been inserted into the connector body  112  to lock the coaxial cable  10  in place. 
     It will be appreciated that the connector ports  110  that are described above may be used on any appropriate RF subscriber drop unit including RF signal splitters, directional couplers, tap units, signal amplifiers, ground blocks, inline filters, signal conditioning units and the like. It will also be appreciated that the above-identified RF subscriber drop units may have any appropriate number of input and output ports (e.g., a 1×2 splitter, a 1×4 splitter, a 1×8 splitter, etc.). It will further be appreciated that some of the connector ports on a given RF subscriber drop unit may comprise connector ports according to embodiments of the present invention while other connector ports may comprise, for example, conventional female connector ports such as the female connector port depicted in  FIG. 5 . 
     In the above-described embodiment of the present invention, the conductive spark gap unit  170  is positioned around the contact tail  158  of spring contact  150 . It will be appreciated, however, that in other embodiments, the conductive spark gap unit  170  may be positioned around other parts of the spring contact  150  such as, for example, the base  152  or the cantilevered arms  154 ,  156 . It will also be appreciated that other spring contacts may be used that are designed differently than the spring contact  150  discussed above. 
     While in the above embodiments the conductive spark gap unit  170  is used on an “integrated” connector port in which the coaxial cable  10  is compression terminated directly into the connector port  110 , it will be appreciated that in other embodiments the conductive spark gap unit  170  may be used on a standard externally threaded female connector port such as the connector port depicted in  FIG. 5 . 
     The conductive spark gap units according to embodiments of the present invention may provide a number of advantages over conventional spark gap structures. For example, many conventional spark gap units are implemented on a printed circuit board of an RF subscriber drop unit. While this may simplify the manufacture of the RF subscriber drop unit, such printed circuit board mounted or implemented spark gap units may be less likely to fully protect the RF subscriber drop unit from damage during high voltage spikes, and may not protect well against repeated high voltage spikes. Additionally, the conductive spark gap units according to embodiments of the present invention may exhibit high voltage spike limits, shorter assembly times and reduced costs compared to conventional spark gap units. 
     The present invention has been described above with reference to the accompanying figures, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth above. Those skilled in the art will readily appreciate that many modifications are possible to the exemplary embodiments described above that do not materially depart from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the claims. 
     In the description above and in the accompanying figures, like numbers refer to like elements unless otherwise indicated. Certain components or features may be exaggerated in the figures for clarity. 
     It will be understood that in the above description when a feature or element is referred to as being “on” another feature or element, it can be directly on the other feature or element or intervening features and/or elements may also be present. In contrast, when a feature or element is referred to as being “directly on” another feature or element, there are no intervening features or elements present. It will also be understood that, when a feature or element is referred to as being “connected”, “attached” or “coupled” to another feature or element, it can be directly connected, attached or coupled to the other feature or element or intervening features or elements may be present. In contrast, when a feature or element is referred to as being “directly connected”, “directly attached” or “directly coupled” to another feature or element, there are no intervening features or elements present. Although described or shown with respect to one embodiment and/or figure, the features and elements so described or shown can apply to other embodiments and/or figures. 
     The terminology used in the present specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
     Spatially relative terms, such as “under”, “below”, “lower”, “over”, “upper” and the like, may be used herein for ease of description to describe one element or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is inverted, elements described as “under” or “beneath” other elements or features would then be oriented “over” the other elements or features. Thus, the exemplary term “under” can encompass both an orientation of over and under. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. Similarly, the terms “upwardly”, “downwardly”, “vertical”, “horizontal” and the like are used herein for the purpose of explanation only unless specifically indicated otherwise. 
     As used herein, the term “longitudinal” and derivatives thereof refer to the direction defined by the central axis of a coaxial connector, which is generally coexistent with the central axis of any coaxial cable that the coaxial connector is installed on when the coaxial cable is fully extended in a straight line. This direction may also be referred to herein as the “axial” direction. 
     It will be understood that although the terms first and second are used herein to describe various features or elements, these features or elements should not be limited by these terms. These terms are only used to distinguish one feature or element from another feature or element. Thus, a first feature or element discussed below could be termed a second feature or element, and similarly, a second feature or element discussed below could be termed a first feature or element without departing from the teachings of the present invention. Well-known functions or constructions may not be described in detail for brevity and/or clarity.