**Exhibit
      10(x)**


**INSTRUMENT
      OF AMENDMENT TO THE**


**MERRIMAC
      INDUSTRIES, INC.**


**AMENDED
      AND RESTATED SEVERANCE PLAN**


**(AS
      ADOPTED ON MARCH 29, 2006)**





**WHEREAS,** Merrimac
      Industries, Inc. (the “Company”) maintains the Merrimac Industries, Inc. Amended
      and Restated Severance Plan (the “Plan”); and


**WHEREAS,** Section
      10 of the Plan provides that the Board of Directors of the Company (the “Board”)
      may amend the Plan in certain respects upon notice to all Plan participants;
      and


**WHEREAS,** the
      Board
      wishes to amend the Plan.


**NOW,
      THEREFORE,** the
      Plan
      is hereby amended, effective December 13, 2007, as follows:




5.  Section
      2
      of the Plan is amended by adding the following new definition immediately after
      the definition of “Date of Termination” and immediately before the definition of
“Disability”:




““Delegate”
      shall mean such person or persons to whom the Board has delegated authority
      with
      respect to the Plan.”




6.  The
      first
      sentence of the definition of the term “Participant” in Section 2 of the Plan is
      amended to read in its entirety as follows




““Participant”
      shall mean each key executive management employee of the Company or any of
      its
      subsidiaries who shall be designated from time to time by the Board (or its
      Delegate).”







7.  Section
      3(a)(i) of the Plan is amended to read in its entirety as follows:




“(i)  The
      Company shall pay to the Participant, in accordance with the Company’s regular
      payroll schedule, an amount equal to an amount designated from time to time
      by
      the Board (or its Delegate), such amount being either one time or two times
      the
      Annual Base Salary of the Participant; provided that such amount cannot be
      changed following a Change in Control.”




8.  Section
      3(c) of the Plan is amended to read in its entirety as follows:




“(c)  All
      Severance Payments under Section 3(a)(i) shall be payable at such times as
      determined by the Board (or its Delegate), provided that all such Severance
      Payments shall be made and completed prior to the later of (x) March 15 of
      the
      calendar year following the calendar year in which such termination occurs
      or
      (y) two and one-half months after the end of the Company’s taxable year in which
      such termination occurred; provided, further, that such Severance Payments
      shall
      be made in accordance with Section 409A of the Code.”




9.  Section
      4
      of the Plan is amended to read in its entirety as follows:




“4.  Additional
      Arrangements. As a condition to the Participant receiving Severance Payments
      pursuant to Section 3 above (such Severance Payments being consideration for
      the
“Arrangements” defined below), the Participant shall enter into such
      non-competition/non-solicitation/confidentiality arrangements and restrictive
      covenants (“Arrangements”) as the Board (or its Delegate) shall deem
      appropriate.”




**MERRIMAC
                INDUSTRIES, INC.**By:
            /s/
                Robert V. CondonName:
                Robert V. CondonTitle:   
                Vice President, Finance and
              Chief Financial OfficerDate:   
                December 13, 2007


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