EXHIBIT 4.1(f)
                       CERTIFICATE OF OWNERSHIP AND MERGER

                                       OF

                         DESIGN DEVELOPMENT INCORPORATED

                           (a California corporation)

                                      into

                                 METRO-TEL CORP.
                            (a Delaware corporation)

It is hereby certified that:

         1.  METRO-TEL   CORP   (hereinafter   sometimes   referred  to  as  the
"Corporation") is a business corporation of the State of Delaware.

         2. The  Corporation  is the owner of all of the  outstanding  shares of
stock of DESIGN DEVELOPMENT INCORPORATED, which is a business corporation of the
State of California.

         3. The laws of the  jurisdiction of organization of DESIGN  DEVELOPMENT
INCORPORATED  permit the merger of a business  corporation of that  jurisdiction
with a business corporation of another jurisdiction.

         4. The Corporation hereby merges DESIGN  DEVELOPMENT  INCORPORATED into
the Corporation.

         5. The following is a copy of the  resolutions  adopted on June 7, 1988
by  the  Board  of  Directors  of the  Corporation  to  merge  the  said  DESIGN
DEVELOPMENT INCORPORATED into the Corporation:

                                    RESOLVED,     that    DESIGN     DEVELOPMENT
                           INCORPORATED  be merged  into this  Corporation,  and
                           that all of the estate, property, rights, privileges,
                           powers,   and   franchises   of  DESIGN   DEVELOPMENT
                           INCORPORATED  be  vested in and held and  enjoyed  by
                           this  Corporation  as fully and  entirely and without
                           change or diminution as the same were before held and
                           enjoyed  by DESIGN  DEVELOPMENT  INCORPORATED  in its
                           name;


                                    RESOLVED,  that this Corporation  assume all
                           of   the    obligations    of   DESIGN    DEVELOPMENT
                           INCORPORATED;

                                    RESOLVED,  that this Corporation shall cause
                           to  be  executed  and  filed   and/or   recorded  the
                           documents  prescribed  by the  laws of the  State  of
                           Delaware, by the laws of the State of California, and
                           by the laws of any other appropriate jurisdiction and
                           will cause to be performed all necessary  acts within
                           the    jurisdiction   of   organization   of   DESIGN
                           DEVELOPMENT  INCORPORATED and of this Corporation and
                           in any other appropriate jurisdiction;

                                    RESOLVED,  that  the  effective  time of the
                           Certificate  of Ownership and Merger  setting forth a
                           copy of these resolutions shall be June 30, 1988, and
                           that,  insofar as the General  Corporation Law of the
                           State of Delaware  shall  govern the same,  said time
                           shall be the effective Merger time.

Executed on June 7, 1988.


                                        METRO-TEL CORP.


                                        By:/s/ Vernerando J. Indelicato  
                                               ---------------------------------
                                               Vernerando J. Indelicato,
                                               President


Attest:

/s/Lloyd Frank    
- -----------------------                                
Lloyd Frank, Secretary

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