Exhibit 10 (a)


                    AMENDED AND RESTATED EMPLOYMENT AGREEMENT


     This AMENDED AND RESTATED EMPLOYMENT  AGREEMENT (the "Agreement"),  entered
into as of January 1, 1998,  is by and between  MERRIMAC  INDUSTRIES,  INC. (the
"Company") and MASON N. CARTER (the "Executive").

     This Agreement  amends and restates the EMPLOYMENT  AGREEMENT,  dated as of
December 19, 1996, by and between the Company and the Executive  (the  "Original
Agreement").

     In  consideration  of the promises in this  Agreement,  the  mutuality  and
sufficiency of which are hereby acknowledged, the parties agree as follows:

     1.  Employment.  The Company hereby employs the Executive and the Executive
hereby  accepts  employment  by the Company under the terms and  conditions  set
forth in this Agreement. The Executive shall be based at the principal executive
offices of the  Company in West  Caldwell,  New  Jersey,  except for  reasonable
required travel on Company business.

     2. Term. Subject to the provisions of Paragraph 6  herein, the initial term
of the  Executive's  employment  under this  Agreement will commence on the date
hereof  and will  end on  December  31,  2002  (the  "Initial  Term"),  and will
automatically  renew for successive twelve month periods  commencing  January 1,
2003, unless:

     (i) either party gives written  notice of  termination of this Agreement to
the other  party at least six (6)  months  prior to the end of the then  present
term, in which case the Executive's  employment will terminate at the end of the
then present term; or

                                      -1-
<PAGE>

     (ii) the Executive's  employment is terminated  under Paragraph 6, in which
event the Agreement will terminate on the date set forth in Paragraph 6.

     3. Title and Duties.  

     (a) The Executive will serve as the President and Chief  Executive  Officer
of the Company.  The Executive  shall be responsible  for performing such duties
and  responsibilities  that  are  consistent  with his  position  or that may be
assigned  to him from  time to time by the  Board of  Directors  of the  Company
consistent  therewith.  The Executive agrees to devote  substantially all of his
working time, attention,  skill and energy to the duties set forth herein and to
the operations of the Company,  to use his efforts to promote the success of the
Company,  and to cooperate  fully with the Board of Directors in the advancement
of the  best  interests  of the  Company.  Nothing  in this  Agreement  prevents
Executive  from  engaging in additional  activities in connection  with personal
investments  and  community  affairs,  or serving as a director  for one or more
other  corporations,  as are consistent with the Executive's  duties  hereunder.

     (b)The  Executive  currently  serves as a director of the  Company.  During
theperiod of  Executive's  service as a director of the Company,  the  Executive
shall not be entitled to receive any additional  compensation as a director, but
shall  be  entitled  to  reimbursement  of  expenses  reasonably  incurred  as a
director,  in accordance with the Company's  policies for such  reimbursement as
are in effect from time to time.  The Company will indemnify the Executive as an
officer and director,  to the same extent as it  indemnifies  other officers and
directors, consistent with the Company's By-laws.

     4.  Compensation  and Related  Matters.  In  consideration  for Executive's
services  during the Company's 1998 fiscal year,  Executive shall receive a base
salary at the annual rate of Two Hundred Forty Thousand Dollars (U.S.  $240,000)
("Base  Salary").  The Base  Salary  shall be  payable  in  accordance  with the
Company's  regular payroll  schedule,  from which the Company shall withhold and
deduct all federal and state income,  social  security and disability  taxes and
other deductions as required by applicable laws.

                                      -2-
<PAGE>

The Base Salary will be reviewed by the Board of  Directors  on an annual
basis and may be adjusted to reflect the  Executive's  performance and the scope
and success of the Company;  provided,  however, that during the Initial Term of
this Agreement,  the Executive's Base Salary shall not be less than $240,000. 

     5.Employment  Benefits.  During the term of this  Agreement,  the Executive
shall be eligible for the following benefits:
   
     (a) Employee Benefits.  The Executive  shall be entitled to participate in
the  Company's  employee  benefit  plans,  including  but not limited to medical
benefits,  life insurance,  employee stock purchase  plans,  stock option plans,
long-term  incentive  plans,  401(k) plan and profit sharing plans, as may be in
effect from time to time, on terms and conditions at least as favorable as those
provided  to any other  executive  officer  of the  Company.  

     (b)  Vacation and  Holidays.  The  Executive  shall be entitled to four (4)
weeks paid vacation per year,  plus those paid holidays to which other similarly
situated  employees  of the  Company  shall be  entitled.  

     (c) Bonuses and Stock Options.  The Executive  shall be eligible to receive
bonuses and stock  options,  to the extent bonuses and stock options are awarded
by the  Company as  determined  within the sole  discretion  of the  appropriate
committee of the Board of Directors and/or the Board of Directors.

     (d) Automobile. The Executive shall be entitled to the use of an automobile
at the Company's expense, up to $700 per month, for the Executive's  performance
of his duties under this  Agreement;  provided,  however,  that such $700 amount
shall be adjusted  from year to year,  commencing on January 1, 1999, to reflect
any percentage  increases in the Consumer Price Index that have occurred  during
the preceding  year. For the purpose of this  Agreement,  "Consumer Price Index"
means the Consumer  Price Index  published by the Bureau of Labor  Statistics of
the  United  States  Department  of Labor.  The  automobile  allowance  shall be
provided,  at the Executive's option, either through a Company car, either owned
or leased by the Company, or through prompt reimbursement by the Company for the
costs of an automobile  owned or leased by the  Executive.  

                                      -3-

<PAGE>
The Company shall be responsible  for the costs of  maintenance  and repair
and  applicable  insurance  and gasoline  costs  incurred by the  Executive  for
business  purposes in connection with the  Executive's  use of such  automobile,
provided that the Executive submits in a timely manner appropriate documentation
supporting  each such cost. If the Company  leases the car, the Executive  shall
have the option to purchase the car at the end of the lease term.

     (e) Expenses.  During his  employment  hereunder,  the  Executive  shall be
entitled  to receive  prompt  reimbursement  for all  reasonable  and  necessary
expenses  incurred  by him in  performing  services  hereunder  (including  as a
director,  if appropriate),  provided that the Executive  properly  accounts for
such expenses in accordance with the Company's policy as then in effect.

     (f) Term Life  Insurance.  During the term of this  Agreement,  the Company
shall pay the cost of establishing  and  maintaining  term life insurance on the
Executive  at standard  premium  rates in an amount of $500,000  payable to such
beneficiaries as the Executive may from time to time designate;  provided,  that
(i) if such term life insurance  cannot be purchased at standard  premium rates,
the Executive may elect to pay to the Company the difference between the cost of
such life  insurance  at  non-standard  rates and the cost which would have been
incurred by the Company if it obtained term life  insurance at standard rates or
to relieve the Company of its obligation to establish and pay for such term life
insurance,  and (ii) the Executive  consents to the  Company's  purchase of "key
man" life insurance in such amount as the Company reasonably deems necessary and
appropriate  and agrees to cooperate with the Company in  establishing  such key
man and  other  life  insurance,  including,  but  not  limited  to,  undergoing
reasonably requested medical exams and/or tests.

     6. Termination of Employment.  

     (a) Death. The Executive's  employment under this Agreement shall terminate
immediately  upon  his  death.  In such  event,  the  Company  shall  pay to the
Executive's  estate all salary and benefits  accrued but unpaid through the date
of death,  and the  Company  shall not have 

                                      -4-
<PAGE>
any further  obligations  under this  Agreement,  except for any accrued or
vested  benefits under this Agreement or any benefits  provided to the Executive
under the Company's 1993 Stock Option Plan (the "1993 Stock Option  Plan"),  the
Company's  Long-Term   Incentive  Plan  (the  "Long-Term   Incentive  Plan")  or
otherwise, or as may be required by law.

     (b)  Disability.  The  Executive's  employment  under this Agreement  shall
terminate if the Executive has a "Disability"  (as defined herein) as reasonably
determined by the Board of Directors.  For purposes of this Agreement,  the term
"Disability" means that (i) as a result of physical or mental illness or injury,
the Executive is unable to perform the essential duties of his position or poses
a direct  threat to the safety and health of Executive or others and there is no
reasonable  accommodation  that can be provided by the Company  that would allow
Executive to perform the essential functions of his position as determined under
applicable  law; or (ii) the  Executive is absent from his position for a period
of ninety (90) consecutive work days or for a period of 120 non-consecutive work
days in a  twelve-month  period.  In such event,  the  Company  shall pay to the
Executive all salary and benefits  accrued but unpaid through the date the Board
of Directors reasonably determines that the Executive has a Disability,  and the
Company shall not have any further obligations under this Agreement,  except for
any accrued or vested benefits under this Agreement or any benefits  provided to
the Executive under the 1993 Stock Option Plan, the Long-Term  Incentive Plan or
otherwise,  or as may be required by law. 

     (c) For Cause.  Notwithstanding  any of the  foregoing  provisions  of this
Agreement,  the  Company  may,  at any time  during  the term of this  Agreement
without  prior  notice,  discharge  the  Executive  for "Cause" (as  hereinafter
defined).  For the purposes of this  Agreement,  the Company  shall be deemed to
have Cause to  terminate  the  Executive's  employment  hereunder  for:  (i) the
willful failure of the Executive to perform his normal and customary  duties for
an extended period for any reason other than death or total disability; (ii) the
Executive's  gross  negligence  if such  gross  negligence  is not  cured by the
Executive  within ten days after receipt of written notice  thereof,  or willful
misconduct,  including but not limited to, fraud,  embezzlement  or  intentional
misrepresentation;  (iii)  the  Executive's 

                                      -5-
<PAGE>

commission of, or indictment or conviction for, a felony;  (iv) the willful
engagement of the Executive in competitive  activities against the Company which
includes, without limitation,  purposely aiding a competitor of the Company; (v)
the Executive's  misappropriation  of a material  opportunity of the Company; or
(vi) the violation of any material  term of this  Agreement by the Executive and
failure  to cure  within  ten days  after  receipt  of  written  notice  of such
violation or, if reasonable under the  circumstances,  such additional period of
time during which the  Executive  is using his best  efforts to so cure,  not to
exceed thirty (30) days in total.  If the Executive is dismissed for Cause,  the
Company  shall pay to  Executive  all salary  and  benefits  accrued  but unpaid
through  the date of  termination,  and the  Company  shall not have any further
obligations  under this  Agreement,  except for any  accrued or vested  benefits
under this Agreement,  the 1993 Stock Option Plan, the Long-Term  Incentive Plan
or  otherwise,  or as may be required  by law.  

     (d) Notice of  Termination.  Any  termination  of employment by the Company
shall be communicated  by a written notice of termination to the Executive.  

     (e)  Certain  Payments  Upon  Termination.  Subject  to  Section  7 of this
Agreement, if the Executive's employment is terminated by the Company before the
end of the term of this Agreement other than by death,  Disability or for Cause,
the Company  shall  provide the  following  to the  Executive:  (i) payment on a
monthly basis of Base Salary (less applicable  withholdings) as in effect on the
date of termination, from the date of termination to the later of (A) the end of
the then  present  term or (B) the date  which is 12  months  after  the date of
termination,  (ii) continued group medical  coverage,  under the Company's group
medical plan in effect from time to time, under the same terms and conditions as
provided  to  comparable  employees,  for the same period as payment of the Base
Salary above, (iii) payment of an amount representing annual bonuses (calculated
and paid as set forth herein), (iv) payment of the car allowance as set forth in
Paragraph  5(d) for the lesser of one year from the date of  termination  or for
the period from the date of  termination to the end of the Agreement and (v) the
option to assume the lease payments of the automobile  provided to the Executive
pursuant to Paragraph 

                                      -6-

<PAGE>

5(d) of this Agreement, assuming the leased automobile is a Company car, or
to purchase  such  automobile in  accordance  with the terms of its lease;  and,
further, all unvested stock options that have been granted as of the date hereof
under the 1993 Stock Option Plan and the  Long-Term  Incentive  Plan held by the
Executive  shall  immediately  vest, and be exercisable in accordance with their
terms. In the event that the Executive's employment is terminated by the Company
before the end of the term of the  Agreement  other than as by  contemplated  by
Paragraph  6(a),  (b) or (c),  including any  termination  of  employment  under
Paragraph 7 upon a Change in Control,  the annual  bonus to which the  Executive
might  otherwise be entitled shall be an amount equal to 20% of the  Executive's
Base Salary in effect on the date of termination,  which amount shall be paid in
respect of each period of twelve months  remaining  during the then present term
of this Agreement, and a pro-rated amount shall be paid in respect of any period
of less than twelve  months.  Any such  payments  for bonus shall be made at the
time that other  annual  bonuses  are paid to other  executive  officers  of the
Company (or if no annual bonus is paid during a particular  year, in December of
the applicable year).

     7. Change in Control.

     (a) Payments.  Within twelve (12) months  following the date of a Change in
Control (as defined herein),  if the Executive  resigns from his employment with
the Company for Good Reason (as defined  herein) or is dismissed  without Cause,
the Company  agrees to pay  Executive  the  greater of (a) 24 months  salary and
benefits  (including  bonus as calculated  in Paragraph  6(e)) or (b) salary and
benefits  from  the  date of  resignation  or  dismissal  to the end of the then
present term of the  Agreement,  such amounts to be  annualized  and paid over a
period of 12 months in accordance  with the  Company's  regular  salary  payment
procedures.  In the  event of a Change  in  Control,  all  unvested  options  to
purchase  shares of common stock,  par value $.50 per share, of the Company that
were  granted by the  Company and are held by the  Executive  on the date hereof
("Executive  Options") shall become  immediately  exercisable and all rights 

                                      -7-

<PAGE>
and benefits  relating to such Executive Options may be exercised and shall
become fixed and not subject to change or revocation by the Company.

     (b) Excise Tax. To the extent  that any payment  made under this  Agreement
may be subject to the excise tax  imposed  under  Section  4999 of the  Internal
Revenue Code of 1986, as amended from time to time, the Company shall reduce the
amount of such payments by the minimum  amount  necessary to avoid being subject
to such excise tax.

     (c) Definitions.  "Good Reason" is defined as a material  diminution of the
Executive's  duties  and  responsibilities  or a  substantial  reduction  in the
Executive's  compensation and benefits.  A "Change in Control" will be deemed to
have  occurred if (a) the  Company is merged or  consolidated  with,  or, in any
transaction or series of transactions,  all or substantially all of the business
or  assets  of the  Company  shall be sold or  otherwise  acquired  by,  another
corporation or entity and, as a result thereof,  the stockholders of the Company
immediately  prior  thereto  shall not have at least 50% or more of the combined
voting power of the  surviving,  resulting or transferee  corporation or entity;
(b) any  person  (as  that  term is used in  Sections  13(d)  and  14(d)  of the
Securities Exchange Act of 1934, as amended,) who is not now a current affiliate
or a 5% or more holder, is or becomes the beneficial owner (as that term is used
in  Section 13(d)  of the Exchange Act and the applicable rules and regulations)
of stock of the  Company  entitled  to cast more than  (25%) of the votes at the
time entitled to be cast  generally  for the election of directors;  or (c) more
than more than 50% of the members of the Board of Directors of the Company shall
not be Continuing  Directors (which term, as used herein, means the directors of
the Company  (i) who were  members of the Board of  Directors  of the Company on
December 1,  1997 or (ii) who  subsequently  became directors of the Company and
who were elected or designated to be candidates  for election as nominees of the
Board  of  Directors,  or whose  election  or  nomination  for  election  by the
Company's  stockholders was otherwise  approved,  by a vote of a majority of the
Continuing Directors then on the Board of Directors).

                                      -8-

<PAGE>

     (d) No Mitigation.  The Company agrees that, if the Executive  resigns from
his  employment  with the Company for Good Reason or is dismissed  without Cause
within  twelve  (12)  months  following  the date of a Change  in  Control,  the
Executive  is not  required  to seek other  employment  or attempt in any way to
reduce any amounts  payable to the  Executive  by the  Company  pursuant to this
Section 7.  Further,  the amount of any payment or benefit to be received by the
Executive  pursuant to this  Section 7 (other than  health  insurance  benefits)
shall not be reduced by any  compensation  earned by the Executive as the result
of employment by another employer, by retirement benefits, or offset against any
amount  claimed  to be  owed  by  the  Executive  to the  Company  or any of its
subsidiaries or otherwise.

     8. Confidential  Information.  The Executive agrees not to disclose, either
while in the  Company's  employ or at any time  thereafter,  to any  person  not
employed by the Company,  or not engaged to render services to the Company,  any
confidential  information  obtained  by him while in the employ of the  Company,
including,  without limitation, any of the Company's inventions,  software, data
lists,  client lists,  trading policies,  pricing  policies,  business plans, or
customer or trade secrets;  provided,  however,  that this  provision  shall not
preclude the Executive  from use or disclosure  of  information  which is in the
public domain or from disclosure  required by law or court order.  The Executive
also agrees that upon  leaving the  Company's  employ he will not take with him,
without the prior written consent of the Board of Directors, any document of the
Company,  which is of a  confidential  nature  relating  to the  Company  or its
affiliates, or, without limitation,  relating to its or their customers or trade
secrets.

     9.  Non-Competition.  (a) The Executive  agrees that if his employment with
the Company terminates for Cause, or he leaves the Company  voluntarily  without
Good Reason, he will not, without the prior written consent of the Company,  for
a period of twelve  (12)  months  thereafter,  alone or with or for  others,  in
whatever  capacity,  directly or  indirectly,  solicit or attempt to solicit for
business in  competition  with the Company  clients or  customers of the Company
with whom he 

                                      -9-
<PAGE>

did business during his employment with the Company,  or solicit or
attempt to solicit employees of the Company to leave the Company's  employ.  

(b)The Executive expressly  acknowledges and understands that the remedy of
law for any  breach by him of this  Section 9 will be  inadequate,  and that the
damages  flowing  from any such  breach  are not  readily  susceptible  to being
measured  in  monetary  terms.  Accordingly,  it is  acknowledged  that upon the
Executive's  violation of any  provision of this Section 9, the Company shall be
entitled  to  immediate  injunctive  relief  and may  obtain a  temporary  order
restraining any threatened or further breach. Nothing in this Section 9 shall be
deemed to limit the Company's remedies at law or in equity for any breach by the
Executive  of any of the  provisions  of this  Section 9 which may be pursued or
availed of by the  Company.  

(c) If  following  termination  of the  Executive's  employment  any of the
restrictions  pursuant  to this  Section 9 shall for any reason be held by to be
excessively broad as to duration,  geographical scope, activity or subject, such
restrictions shall be construed so as to thereafter be limited or reduced to the
extent  required to be enforceable in accordance  with  applicable law; it being
understood  and agreed that by execution of this  Agreement  the parties  hereto
regard such  restrictions  as reasonable  and compatible  with their  respective
rights.

     10. Entire Agreement.  This Agreement contains the entire agreement between
the parties with respect to the subject  matter of this Agreement and supersedes
all prior agreements and  understandings,  oral or written,  between the parties
with respect to the subject  matter of this  Agreement.  This  Agreement  may be
amended only by an agreement in writing signed by both parties.

     11.  Governing  Law;  Arbitration.  This  Agreement will be governed by and
construed in accordance with the laws of the State of New Jersey, without giving
effect to the  principles  of conflicts of laws.  All  disputes  concerning  the
Executive's  employment with the Company, the termination thereof, the breach by
either party of the terms of this Agreement or any other 

                                      -10-

<PAGE>

matters relating to or arising from Executive's employment with the Company
shall be resolved in binding  arbitration  in a proceeding  administered  by and
under the rules and regulations of the American Arbitration Association,  in the
AAA  office  located  in  Newark,  New  Jersey.  The  arbitrator  shall not have
authority to modify or change any of the terms of this  Agreement.  Both parties
and the arbitrator will treat the arbitration  process and the activities  which
occur  in the  proceedings  as  confidential.  If the  Executive  brings a claim
against  the  Company  to enforce  the terms of this  Agreement  and  achieves a
successful  result,  other  than as a result  of a  negotiated  settlement,  the
Company shall be liable to pay reasonable  attorneys' fees and expenses incurred
by the Executive.

     12. Binding Effect;  Delegation of Duties  Prohibited.  This Agreement will
inure  to the  benefit  of and  will be  binding  upon  the  parties  and  their
respective successors, heirs and legal representatives.  Neither the Company nor
the  Executive  may assign or  delegate  their  respective  performance  of this
Agreement.

     13. Notices.  All notices and other communications that are required or may
be given under this Agreement must be in writing and will be deemed to have been
duly given when  delivered in person,  when received by telecopy  (provided that
the  sender  has  retained  a copy of the  notice  showing  the date and time of
receipt), upon delivery by a nationally recognized overnight courier service, or
three days after being  mailed by  registered  or  certified  second class mail,
postage prepaid,  return receipt  requested,  to the party to whom the notice is
being given, as follows:

                           If to the Company:

                           Merrimac Industries, Inc.
                           41 Fairfield Place
                           West Caldwell, New Jersey 07006
                           Facsimile: (973) 575-0531
                           Attention:  Chairman of the
                                         Compensation Committee

                                      -11-

<PAGE>

                           With a Copy to:

                           Chadbourne & Parke LLP
                           30 Rockefeller Plaza
                           New York, New York 10112
                           Facsimile:  (212) 541-5369
                           Attention:  Thomas C. Meriam, Esq.

                           If to the Executive:

                           Mason N. Carter
                           Box 7
                           75 Old Farm Road
                           Bedminster, New Jersey  07921


                           With a copy to:

                           Mail To:

                           Gibbons, Del Deo, Dolan, Griffinger & Vecchione
                           1 Riverfront Plaza
                           Newark, New Jersey 07102-5497
                           Attn:  John M. Elias, Esq.
                           Facsimile No.: (973) 540-7300



     IN WITNESS WHEREOF, the parties have executed this Agreement as of the date
and year second above written.

                           MERRIMAC INDUSTRIES, INC.

                           By: /s/ Robert V. Condon
                               --------------------
                           Name: Robert V. Condon

                           Title: Vice President, Finance and
                                     Chief Financial Officer



                               /s/ Mason N. Carter 
                               -------------------
                                   Mason N. Carter

                                      -12-

<PAGE>

Exhibit 10 (b)

                            STOCK PURCHASE AGREEMENT


     STOCK PURCHASE AGREEMENT, dated as of May 4, 1998 (the "Agreement"), by and
between MERRIMAC INDUSTRIES, INC. (the "Company") and MASON N. CARTER ("Buyer").

     WHEREAS, the Company desires to sell and deliver to Buyer and Buyer desires
to purchase and receive from the Company,  upon the terms and conditions  herein
set forth,  20,000  shares (the  "Shares") of Common  Stock,  par value $.50 per
share, of the Company; and

     WHEREAS,  the Company and Buyer had  previously  entered  into an agreement
dated as of May 4, 1998  providing  for the purchase by Buyer of the Shares from
the Company, which agreement is superseded by this Agreement;

     NOW,  THEREFORE,  in  consideration  of the premises  and mutual  covenants
hereinafter set forth, the parties hereto agree as follows:

      1. Purchase and Sale; Purchase Price.

     (a) Subject to the conditions set forth in this  Agreement,  on the Closing
Date (as defined  below) the Company shall sell,  assign,  transfer,  convey and
deliver to Buyer the Shares and Buyer shall purchase the Shares from the Company
for a purchase  price as set forth below.  On the Closing Date,  (i) the Company
shall deliver to Buyer certificates representing the Shares in the name of Buyer
and (ii) the Company  and Buyer shall  execute and deliver to the other party an
Amended and  Restated  Pledge  Agreement  (the "Pledge  Agreement")  in the form
attached hereto as Exhibit A.

     (b) The  purchase  price for the Shares  shall be $12.75  per Share,  for a
total  purchase  price of $255,000 (the  "Purchase  Price").  The Purchase Price
shall be paid on the Closing Date by Buyer to the Company by delivery of Buyer's
promissory note (the "Note") in the form attached hereto as Exhibit B.

     2. Required Deliveries.  The Company's obligations hereunder are subject to
the  satisfaction  (or waiver by the Company) of the  following  condition on or
before the  Closing  Date:  the  execution  and  delivery by Buyer of the Pledge
Agreement and the Note.

     3. Closing Date.  The Closing Date shall be May 4, 1998.  The Closing shall
be held at the offices of Merrimac  Industries,  Inc., 41 Fairfield Place,  West
Caldwell, New Jersey at 10:00 a.m. on the Closing Date.

     4. Representations, Warranties and Covenants.

     (a)  Authority.  The Company  represents  and warrants that the  execution,
delivery and  performance by the Company of this Agreement and the  consummation
of the  transactions  contemplated  hereby  have  been  duly  authorized  by all
necessary  and  proper  action,  and this  Agreement  is the valid  and  binding
obligation  of the Company  enforceable  in  accordance  with its terms,  except
insofar as enforcement may be affected by 

                                      -1-
<PAGE>

bankruptcy, reorganization or similar laws relating to creditors' rights in
general and general principles of equity.  Buyer represents and warrants that he
has all  requisite  power and  authority  to  execute,  deliver  and perform his
obligations  under this  Agreement,  the Pledge  Agreement  and the Note.  Buyer
represents and warrants that the execution, delivery and performance by Buyer of
this Agreement,  the Pledge  Agreement and the Note and the  consummation of the
transactions  contemplated  hereby and thereby have been duly  authorized by all
necessary and proper action,  and each of this Agreement,  the Pledge  Agreement
and the  Note is the  valid  and  binding  obligation  of Buyer  enforceable  in
accordance  with its terms,  except  insofar as  enforcement  may be affected by
bankruptcy,  reorganization  or similar laws  relating to  creditors'  rights in
general and general principles of equity.

     (b) Shares.  The Company  represents  and  warrants  that the Shares,  when
delivered to Buyer in accordance with the terms and conditions  hereof,  will be
duly authorized and validly  issued,  will be fully paid and  nonassessable  and
will be free and clear of any liens, pledges, encumbrances, charges, agreements,
claims,  security interests,  equities,  options,  proxies, voting restrictions,
rights of first refusal or other  limitations on disposition or  encumbrances of
any kind (other  than  restrictions  on the  subsequent  transfer of  securities
imposed  generally on sales of securities in non-registered  transactions  under
federal and state securities laws and the restrictions imposed by this Agreement
and the Pledge  Agreement).  On the Closing  Date,  the Company  will deliver to
Buyer good and valid title to the Shares.

     (c)  Knowledgeable  Investor;   Investment  Intent.  Buyer  represents  and
warrants  that (i) he is an  "accredited"  investor as defined in Rule 501(a) of
the Securities Act of 1933, as amended (the "Securities  Act"), (ii) he has such
knowledge and experience in financial and business matters that he is capable of
evaluating  the  merits  and uses of his  investment  in the  Company,  (iii) he
understands and is able to bear the economic risks  associated with the purchase
of the Shares, (iv) he has, on the date hereof,  sufficient  financial resources
to carry out the purchase of the Shares as  contemplated  by this  Agreement and
(v) he is acquiring the Shares for investment  purposes only and not with a view
to, or for sale or resale in connection  with, any public  distribution  thereof
within the meaning of the Securities Act.

     (d) Restricted Shares.  Buyer represents and warrants that he is aware that
the Shares will not be registered  under the  Securities  Act or any  applicable
state securities laws, and agrees that the Shares will not be offered or sold in
the absence of  registration  under the Securities  Act or any applicable  state
securities  laws or an  exemption  from  the  registration  requirements  of the
Securities Act and any applicable  state  securities  laws.  Buyer covenants and
agrees that he will not transfer any Shares in  violation of the  provisions  of
any federal or state securities  laws. In this connection,  Buyer represents and
warrants that he is familiar with Rule 144 of the  Securities  Act, as presently
in effect,  and  understands the resale  limitations  imposed thereby and by the
Securities  Act. Each  certificate  evidencing the Shares shall bear a legend in
substantially the following form:

     "The securities  represented by this  certificate  have not been registered
under the  Securities  Act of 1933,  as amended,  and may not be offered,  sold,
transferred or otherwise  disposed of unless  registered with the Securities and
Exchange  Commission  of  


                                      -2-
<PAGE>

the United States and the securities  regulatory  authorities of applicable
states  or  unless  an  exemption  from  such  registration  is  available.  The
availability  of such  exemption from  registration  is to be established to the
satisfaction of Merrimac Industries, Inc."

     (e) Resale Restriction.  Notwithstanding anything to the contrary contained
in this  Agreement,  Buyer  covenants  and  agrees  that he will not (i) sell or
otherwise  transfer for one year from the date hereof (the "Restricted  Period")
any  Shares  or (ii)  sell or  otherwise  transfer  for one year  following  the
Restricted  Period any Shares unless all of the proceeds to be received by Buyer
as a result of such a sale or transfer  of Shares  after the  Restricted  Period
will be applied to the payment of  outstanding  principal and interest due under
the Note.

     (f) Registration and Listing of Shares. Pursuant to the Registration Rights
Agreement  dated as of the date  hereof  between  the  Company  and  Buyer  (the
"Registration  Rights  Agreement")  and  subject  to the  terms  and  conditions
thereof,  the  Company  will grant  Buyer  "piggy-back"  registration  rights to
register  the  Shares  under the  Securities  Act,  exercisable  only  after the
expiration of the Restricted  Period.  The Company shall use its reasonable best
efforts to cause the Shares to be  approved  for listing on the  American  Stock
Exchange (or any successor stock exchange thereof).

     2. Entire  Agreement;  Binding  Effect;  Governing  Law. This Agreement (a)
shall be binding  upon and shall inure to the benefit of each of the parties and
their respective successors and assigns, provided, however, that Buyer shall not
assign this  Agreement  or any of his  obligations  hereunder  without the prior
written consent of the Company,  and (b) shall be governed by and interpreted in
accordance  with the laws of the State of New Jersey  (without  giving effect to
principles  of  conflicts  of laws)  and (c)  shall,  together  with the  Pledge
Agreement, the Note and the Registration Rights Agreement, constitute the entire
agreement  between the parties  with  respect to the subject  matter  hereof and
thereof and will supersede all prior negotiations, agreements and understandings
of the parties of any nature,  whether  oral or  written,  with  respect to such
subject matter.

     IN WITNESS WHEREOF, the parties have executed this Agreement as of the date
first above written.


                                 MERRIMAC INDUSTRIES, INC.


                                 By: /s/ Robert V. Condon
                                     ----------------------
                                     Name: Robert V. Condon
                                     Title: Vice President, Finance
                                            and Chief Financial Officer



                                     /s/ Mason N. Carter    
                                     -------------------  
                                         Mason N. Carter

                                      -3-
<PAGE>

Exhibit 10 (c)

                      AMENDED AND RESTATED PLEDGE AGREEMENT


     THIS AMENDED AND RESTATED PLEDGE AGREEMENT (this  "Agreement")  dated as of
May 4,  1998 by  MASON  N.  CARTER  ("Pledgor"),  for the  benefit  of  MERRIMAC
INDUSTRIES, INC., a New Jersey corporation ("Holder"),

                              W I T N E S S E T H:

     WHEREAS,  Pledgor has purchased  30,000  shares of common stock,  par value
$.50 per share, of Holder (the "Pledged Shares"); and

     WHEREAS, in connection with the purchase of the Pledged Shares,  Pledgor is
executing  and  delivering to Holder,  and Holder is  accepting,  an amended and
restated  promissory note dated May 4, 1998 (the "Promissory Note") in the total
principal amount of Three Hundred Sixty Thousand Dollars (US $360,000),  bearing
interest as set forth in the Promissory  Note (such principal and interest being
hereinafter  referred to as the "Note  Amount"),  with  interest  and  principal
payments due and payable on the dates set forth in the Promissory  Note (each, a
"Due Date").

     NOW,  THEREFORE,  in consideration of the premises,  and in order to induce
Holder to accept the Promissory Note, Pledgor does hereby agree as follows:

     SECTION 1. Pledge.  Pledgor hereby irrevocably and unconditionally  pledges
to Holder,  and  grants to Holder a security  interest  in, the  following  (the
"Pledged Collateral"):

     (i) the Pledged Shares and the certificates representing the Pledged Shares
and  all  dividends  from  time  to  time  received,   receivable  or  otherwise
distributed  in respect of any or all of the Pledged  Shares  subject to Section
6(c); and

     (ii) to the extent not  covered  above,  all  proceeds of any or all of the
foregoing Pledged Collateral.

     SECTION 2. Security for Obligations. This Agreement secures the obligations
of Pledgor to pay to Holder the  applicable  portions  of the Note  Amount on or
before each Due Date in accordance  with the Promissory Note and all obligations
of Pledgor now or hereafter  existing under this Agreement (all such obligations
of Pledgor being the "Obligations").

     SECTION 3. Delivery of Pledged Collateral. Pledgor shall take all necessary
actions  to  ensure  that  all  certificates  or  instruments   representing  or
evidencing the Pledged Collateral shall be delivered to and held by or on behalf
of  Holder  pursuant  hereto  and  shall be in  suitable  form for  transfer  by
delivery,  or shall be accompanied by duly  executed,  notarized  instruments of
transfer or  assignment  in blank,  all in form and  substance  satisfactory  to
Holder.  Holder  shall have the right,  effective  immediately  upon  failure by
Pledgor to pay the  applicable  portion of the Note Amount on the respective Due
Date,  in its  discretion  and without  notice to Pledgor,  to transfer to or to
register in the name of Holder or any of its  nominees any or all of the Pledged
Collateral.  In  addition,  Holder  shall have the right at any time to exchange
certificates or instruments  representing  or evidencing the Pledged  Collateral
for certificates or instruments of smaller or larger denominations.

                                      -1-
<PAGE>

     SECTION 4. Representations and Warranties.  Pledgor represents and warrants
as follows:

     (a) The pledge of the Pledged  Collateral  pursuant to this  Agreement  and
delivery of  certificates  for the Pledged  Shares creates a valid and perfected
first  priority  security  interest  in the  Pledged  Collateral,  securing  the
Obligations.

     (b) No  authorization,  approval,  or other  action by, and no notice to or
filing with, any  governmental  authority or regulatory  body is required either
(i) for the  pledge  by  Pledgor  of the  Pledged  Collateral  pursuant  to this
Agreement or for the  execution,  delivery or  performance  of this Agreement by
Pledgor  or (ii) for the  exercise  by  Holder  of the  voting  or other  rights
provided  for in this  Agreement  or the  remedies  in  respect  of the  Pledged
Collateral pursuant to this Agreement.  The execution,  delivery and performance
of this Agreement do not contravene any legal or contractual restriction binding
on or affecting Pledgor or the Pledged Collateral.

     (c) This  Agreement  has been duly  executed  and  delivered by Pledgor and
constitutes  the legal,  valid and binding  obligation  of Pledgor,  enforceable
against  Pledgor in  accordance  with its terms,  subject to the  qualification,
however,  that the  enforcement of the rights and remedies  herein is subject to
bankruptcy and other similar laws of general  application  affecting  rights and
remedies  of  creditors  and that  the  remedy  of  specific  performance  or of
injunctive  relief is subject to the  discretion  of the court  before which any
proceedings therefor may be brought.

     SECTION 5.  Further  Assurances.  Pledgor  agrees that at any time and from
time to time,  at the  expense of Pledgor,  Pledgor  will  promptly  execute and
deliver all further instruments and documents, and take all further action, that
may be necessary or desirable,  or that Holder may request,  in order to perfect
and protect any security  interest  granted or purported to be granted hereby or
to enable Holder to exercise and enforce its rights and remedies  hereunder with
respect to any Pledged Collateral.

     SECTION 6. Voting Rights,  Dividends, etc. (a) Unless Pledgor has failed to
pay the  applicable  portion of the Note Amount on or before the  respective Due
Date or has failed to perform any of the other Obligations:

     (i) Pledgor  shall be  entitled  to  exercise  any and all voting and other
consensual rights  pertaining to the Pledged  Collateral or any part thereof for
any  purpose not  inconsistent  with this  Agreement;  provided,  however,  that
Pledgor  shall not  exercise or refrain  from  exercising  any such right if, in
Holder's judgment,  such action would have an adverse effect on the value of the
Pledged  Collateral or any part thereof or would be inconsistent with or violate
any provisions of this Agreement;  and,  provided,  further,  that Pledgor shall
give Holder at least two days' written  notice of the manner in which it intends
to exercise, or the reasons for refraining from exercising, any such right.

     (ii)  Holder  shall  exercise  and  deliver  (or  cause to be  executed  or
delivered)  to Pledgor  all such  proxies and other  instruments  as Pledgor may
reasonably  request for the purpose of enabling  Pledgor to exercise  the voting
and other  rights  which it is entitled to exercise  pursuant to  paragraph  (i)
above.

     (b) Upon the failure of Pledgor to pay the  applicable  portion of the Note
Amount on the  respective  Due Date or the  failure of Pledgor to perform any of
the other  Obligations,  all rights of Pledgor to exercise  the voting and other
consensual  rights which it would otherwise be entitled to exercise  pursuant to
Section  6(a)(i) shall become vested in Holder who shall thereupon have the sole
right to exercise such voting and other consensual rights. 

                                      -2-

<PAGE>

     (c)  Pledgor  shall  not be  entitled  to  receive  and  retain  dividends,
distributions or any other payments in respect of the Pledged Collateral, all of
which shall be and become part of the Pledged  Collateral and shall, if received
by the  Pledgor,  be  received  in trust for the  benefit  of  Holder,  shall be
segregated  from other  funds of  Pledgor  and shall be  forthwith  paid over by
Pledgor to Holder as Pledged  Collateral  in the same form as so received  (with
any necessary  endorsement).  Notwithstanding  the foregoing,  cash dividends in
respect of the Pledged Shares shall be immediately paid by Pledgor to Holder and
applied in accordance with the terms of the Promissory Note; provided,  that the
excess of any such cash dividends over the amount of interest then due under the
Promissory Note shall be paid to Pledgor.

     SECTION 7. Transfers and Other Liens. Without  concurrently  satisfying all
the Obligations,  Pledgor agrees that it will not (a) sell or otherwise  dispose
of, or grant any option with respect to, any of the Pledged  Collateral,  or (b)
create  or  permit to exist any  lien,  security  interest,  or other  charge or
encumbrance upon or with respect to any of the Pledged Collateral except for the
security interest under this Agreement.

     SECTION 8.  Holder  Appointed  Attorney-in-Fact.  Pledgor  hereby  appoints
Holder as Pledgor's attorney-in-fact, with full authority in the place and stead
of  Pledgor  and in the name of  Pledgor  or  otherwise,  and with full power of
substitution, from time to time to take any action and to execute any instrument
which Holder may deem  necessary or advisable to give effect to this  Agreement,
including,  without limitation,  to receive, endorse and collect all instruments
made payable to Pledgor representing any dividend, distribution or other payment
in  respect  of the  Pledged  Collateral  or any part  thereof  and to give full
discharge for the same.

     SECTION 9. Holder May Perform.  If Pledgor  fails to perform any  agreement
contained  herein,  Holder may itself  perform,  or cause  performance  of, such
agreement and the expenses of Holder  incurred in connection  therewith shall be
payable by Pledgor under Section 11.

     Holder shall have no  responsibility  for (i) ascertaining or taking action
with respect to calls, conversions, exchanges, tenders or other matters relative
to any  Pledged  Collateral,  whether  or not  Holder  has or is  deemed to have
knowledge of such matters, or (ii) taking any necessary steps to preserve rights
against any parties with respect to any Pledged Collateral. 

     SECTION 10.  Remedies upon Failure to Pay the Note Amount on a Due Date. If
the  applicable  portion  of the Note  Amount has not been paid on or before the
respective  Due Date or if Pledgor shall have failed to perform any of the other
Obligations:

     (a) Holder may exercise in respect of the Pledged  Collateral,  in addition
to other rights and remedies  provided for herein or otherwise  available to it,
all the rights and remedies of a secured  party upon  default  under the Uniform
Commercial  Code in effect at that time,  and Holder  may also,  without  notice
except as  specified  below,  sell the Pledged  Collateral  at public or private
sale, at any exchange,  broker's board or elsewhere,  for cash, on credit or for
future  delivery,  and upon such  other  terms as Holder  may deem  commercially
reasonable.  Pledgor agrees that, to the extent notice of sale shall be required
by law, at least ten days' notice to Pledgor of the time and place of any public
sale or the time after  which any  private  sale is to be made shall  constitute
reasonable  notification.  Holder  shall  not be  obligated  to make any sale of
Pledged  Collateral  regardless of notice of sale having been given.  Holder may
adjourn any public or private sale from time to time by announcement at the time
and place fixed therefor,  and such sale may, without further notice, be made at
the time and place to which it was so adjourned.

                                      -3-
<PAGE>

     (b) Pledgor  acknowledges that Holder may be unable to effect a public sale
of some  or all  the  Pledged  Collateral  by  reason  of  certain  prohibitions
contained in the Securities Act of 1933, as amended (the  "Securities  Act") and
applicable  state securities laws, and may be compelled to resort to one or more
private sales thereof to a restricted group of purchasers who will be obliged to
agree,  among other things, to acquire such securities for their own account for
investment and not with a view to the distribution  and resale thereof.  Pledgor
acknowledges  and  agrees  that any such  private  sale may result in prices and
other  terms less  favorable  to the seller than if such sale were a public sale
and, notwithstanding such circumstances, agrees that any such private sale shall
be deemed to have been made in a commercially reasonable manner. Holder shall be
under no  obligation  to delay a sale of any of the Pledged  Collateral  for the
period of time  necessary  to permit the issuer of such  securities  to register
such  securities for public sale under the Securities  Act, or under  applicable
state securities laws, even if the issuer would agree to do so.

     (c) Any cash held by Holder as  Pledged  Collateral  and all cash  proceeds
received  by  Holder  in  respect  of any sale  of,  collection  from,  or other
realization  upon  all or  any  part  of  the  Pledged  Collateral  may,  in the
discretion of Holder, be held by Holder as collateral for, and/or then or at any
time thereafter applied (after payment of any amounts payable to Holder pursuant
to Section 11) in whole or in part by Holder to the payment of the Note  Amount.
Any surplus of such cash or cash  proceeds  held by Holder and  remaining  after
payment  in  full of the  Note  Amount  shall  be paid  over  to  Pledgor  or to
whomsoever may be lawfully entitled to receive such surplus.

     SECTION 11. Expenses. Pledgor shall indemnify and hold harmless Holder from
and against all claims, damages,  liabilities and expenses, and will upon demand
pay to Holder  the  amount of any and all  reasonable  expenses,  including  the
reasonable fees and expenses of its counsel and of any experts and agents, which
Holder may incur in connection  with (i) the  administration  or  enforcement of
this Agreement,  (ii) the custody or preservation of, or the sale of, collection
from,  or other  realization  upon,  any of the  Pledged  Collateral,  (iii) the
exercise or  enforcement of any of the rights of Holder  hereunder,  or (iv) the
failure by Pledgor to perform or observe any of the provisions hereof.

     SECTION 12. (a) Addresses for Notices. All notices and other communications
provided for hereunder shall be made by either party in the following manner:

                  If to Holder as follows:
                  Merrimac Industries, Inc.
                  41 Fairfield Place
                  West Caldwell, New Jersey  07006-6287
                  Attention:  Chief Financial Officer

                  If to Pledgor as follows:
                  Mr. Mason N. Carter
                  c/o Merrimac Industries, Inc.
                  41 Fairfield Place
                  West Caldwell, New Jersey  07006-6287

     (b)  Assignment.  Pledgor  shall not assign  this  Agreement  or any of his
obligations hereunder without the prior written consent of Holder.

     SECTION 13.  Continuing  Security  Interest.  This Agreement shall create a
continuing  security interest in the Pledged  Collateral and shall (i) remain in
full force and effect  until  payment in full of the Note Amount and any amounts
required  under  Section 11,  (ii) be binding  upon  Pledgor  and his  permitted
assigns  and (iii)  inure,  together  with the  rights  and 

                                      -4-
<PAGE>

remedies of Holder hereunder,  to the benefit of Holder and its successors,
transferees and assigns.

     SECTION 14. Security Interest  Absolute.  All rights of Holder and security
interests hereunder, and all obligations of Pledgor hereunder, shall be absolute
and unconditional irrespective of:

     (i) any lack of validity or  enforceability  of the Promissory  Note or any
other agreement or instrument relating thereto; or

     (ii) any change in the time, manner or place of payment of, or in any other
term of, all or any of the Note Amount;  or any other  amendment or waiver of or
any consent to any departure from the Promissory  Note or any other agreement or
instrument relating thereto; or

     (iii) any exchange,  release or non-perfection of any other collateral,  or
any release or amendment or waiver of or consent to departure from any guaranty,
for all or any of the Note Amount; or

     (iv) any other  circumstance  which might  otherwise  constitute  a defense
available to, or a discharge of, a surety, a guarantor or a third party pledgor.

     SECTION  15.  Governing  Law.  This  Agreement  shall be  governed  by, and
construed  in  accordance  with,  the  internal  laws of the State of New Jersey
without giving effect to any conflicts of laws provisions of such State.

     SECTION 16. Waiver. No failure or delay on the part of Holder in exercising
any right,  power or  privilege  under this  Agreement  and no course of dealing
between  Pledgor and Holder  shall  operate as a waiver  thereof;  nor shall any
single or partial exercise of any right,  power or privilege  hereunder preclude
any other or  further  notice or demand in  similar  or other  circumstances  or
constitute a waiver of the right of Holder to any other or further action in any
circumstances without notice or demand.

     SECTION 17. Descriptive  Headings.  The descriptive headings of the several
sections of this  Agreement are inserted for  convenience  only and shall not be
deemed to affect the meaning or construction of any of the provisions hereof.

     IN WITNESS  WHEREOF,  Pledgor has caused this Agreement to be duly executed
by its officer thereunto duly authorized as of the date first above written.


                                 /s/ Mason N. Carter 
                                 -------------------
                                     Mason N. Carter

                                      -5-

<PAGE>


Exhibit 10 (d)

                      AMENDED AND RESTATED PROMISSORY NOTE



US $360,000                                          West Caldwell, New Jersey
                                                              May 4, 1998


     FOR VALUE  RECEIVED,  MASON N.  CARTER  ("Payor"),  hereby  unconditionally
promises to pay, in accordance  with the terms of this  promissory  note (as the
same may be amended from time to time, this "Promissory  Note"), to the order of
MERRIMAC  INDUSTRIES,  INC., a New Jersey  corporation,  or its  successors  and
assigns  ("Note  Holder"),  in lawful  money of the United  States of America in
immediately  available funds, on May 4, 2003 and in such account, at such place,
or to such party as Note Holder may designate in writing,  the principal  amount
of  Three   Hundred   Sixty   Thousand   Dollars  (US   $360,000).   Payor  also
unconditionally  promises to pay  interest  quarterly  in arrears  from the date
hereof (as specified  below) on the unpaid  principal  amount of this Promissory
Note  outstanding  from time to time at a rate  calculated  each 12-month period
beginning on the date hereof,  which rate is based upon the weighted  average of
the rates  announced  publicly  from  time to time  during  such  period by Note
Holder's primary lending bank (currently, Summit Bancorp) as its prime rate.

     Payment of this  Promissory  Note is secured by the Pledged  Collateral (as
defined in the Amended and Restated Pledge Agreement dated as of the date hereof
by Payor for the benefit of Note Holder (the  "Pledge  Agreement")),  including,
without limitation,  the Pledged Shares (as defined in the Pledge Agreement) and
any property or interest  provided in addition to or in substitution  for any of
the foregoing.

     Interest on the unpaid principal amount of this Promissory Note outstanding
from time to time shall  accrue  quarterly  in arrears  from the date hereof and
shall be paid on the 4th day of August,  November,  February  and May of each of
1998,  1999,  2000,  2001, 2002 and 2003.  Interest shall be paid from dividends
declared in respect of the Pledged Shares. To the extent that in a given quarter
such dividends are insufficient to pay interest on the date when due, then Payor
shall be liable for the remainder of the interest payment then due.

     Payor may, at its option, prepay all or, from time to time, any part of the
unpaid principal balance of this Promissory Note, together with interest accrued
thereon, without payment of any premium or penalty.

     Payor hereby  waives  presentment,  demand,  notice,  protest and all other
demands and notices in connection  with the delivery,  acceptance,  performance,
default or enforcement of this Promissory Note.

     If Payor's  employment  with Note Holder is terminated  pursuant to Section
6(c) of the Amended and Restated  Employment  Agreement,  dated January 1, 1998,
between  Payor and Note  Holder,  then Note  Holder,  at its option,  by written
notice to Payor, may declare the entire principal amount of this Promissory Note
to be due and payable,  together with accrued  interest  thereon,  without other
notice, demand, presentment or protest, all of which are hereby waived by Payor.

                                      -1-
<PAGE>

     Payor shall not assign this Promissory  Note or its  obligations  hereunder
without the prior written consent of Note Holder.  This Promissory Note shall be
binding upon Payor and its  permitted  assigns and shall inure to the benefit of
Note Holder and its successors and assigns.

     This  Promissory  Note has been  executed and delivered in the State of New
Jersey and shall be governed by, and  construed  and  interpreted  in accordance
with,  the internal laws of the State of New Jersey without giving effect to any
conflicts  of  laws  provisions  of  such  State.  Payor  hereby  expressly  and
irrevocably agrees and consents that any suit, action, or proceeding arising out
of or relating to this Promissory Note may be instituted in any State.

   

                                    /s/ Mason N. Carter 
                                    ------------------- 
                                        Mason N. Carter

                                      -2-

<PAGE>

Exhibit 10 (e)

                     REGISTRATION RIGHTS AGREEMENT                          

     REGISTRATION  RIGHTS AGREEMENT,  dated as of May 4, 1998 (the "Agreement"),
by and between  MERRIMAC  INDUSTRIES,  INC. (the  "Company") and MASON N. CARTER
("Carter"). 

     WHEREAS,  the Company and Carter have entered into a Stock Purchase
Agreement dated as of the date hereof (the "Stock Purchase  Agreement") pursuant
to which the Company has sold and  delivered to Carter and Carter has  purchased
and received from the Company,  upon the terms and conditions set forth therein,
20,000 shares (the "Shares") of Common Stock,  par value $.50 per share,  of the
Company (the "Common Stock");

     NOW,  THEREFORE,  in  consideration  of the premises  and mutual  covenants
hereinafter set forth, the parties hereto agree as follows:

     1. "Piggyback" Registration Rights. (a) If, at any time after one year from
the date  hereof,  the Company  proposes to register  any shares of Common Stock
under the  Securities  Act of 1933,  as amended  (the  "Securities  Act") on any
registration  form  (other  than  Form S-4 and Form  S-8 or any  successor  form
thereof) the Company shall  promptly give prior written  notice of such proposed
registration to Carter at least twenty (20) days before the  anticipated  filing
date of the  registration  statement.  Such notice  shall  describe the proposed
registration and distribution,  including those jurisdictions where registration
or qualification  under the securities or blue sky laws is intended.  Carter may
elect to participate in such proposed registration by giving the Company, within
ten (10) days after such notice has been given by the Company, a written request
to include in such registration all or a portion of the Shares. Any such request
by Carter  shall state the number of Shares to be included in such  registration
and any other information that the Company reasonably  requests in its notice to
Carter.  The Company shall use its reasonable  best efforts to cause any and all
Shares  identified  by Carter to be  registered  under  the  Securities  Act and
qualified under the securities or blue sky laws of any jurisdiction requested by
Carter to the extent necessary to permit the sale or other disposition  thereof;
provided,  however,  that the  Company  shall not be  obligated  to qualify as a
foreign  corporation to do business under the laws of any  jurisdiction in which
it  is  not  then  qualified  or  submit  to  the  service  of  process  in  any
jurisdiction.

     (b) If, at any time after  giving such notice of its  intention to register
any of its  Common  Stock and prior to the  effective  date of any  registration
statement  filed  in  connection  with  such  registration,  the  Company  shall
determine for any reason not to register such Common Stock,  the Company may, at
its election, give notice of such determination to Carter and thereupon shall be
relieved  of its  obligation  to  register  any Shares in  connection  with such
registration.  The Company shall not be obligated to effect any  registration of
any Shares under Section 1(a): (i)  incidental to a  registration  of any of its
Common Stock in  connection  with (A) any merger or  consolidation  with another
company or acquisition  subject to Rule 145 under the Securities Act, or (B) any
dividend  reinvestment  plans or stock option or other employee benefit plans of
the Company or (ii) if Carter is  eligible to resell any of the Shares  pursuant
to an exemption from registration provided by Rule 144 under the Securities Act.

     2.  Underwritten  Offers.  (a) If an  offering is  underwritten  and Carter
chooses to sell all or any  portion of his Shares  pursuant to Section 1, Carter
shall sell through the  underwriters  selected by the Company and shall become a
party to any underwriting agreement between the Company and such underwriter and


                                      -1-


<PAGE>
shall be  subject  to the  terms and  conditions  thereof.  If such  underwriter
selected  by  the  Company  to  manage  the  distribution  of the  shares  being
registered advises the Company in writing that, in its opinion, the inclusion of
the Shares proposed to be sold by Carter would have a material adverse effect on
the  distribution of all such shares of Common Stock,  then the number of Shares
which Carter will be permitted to include in such registration statement will be
reduced to an amount acceptable to the underwriter or underwriters.  The Company
has no obligation to reduce the number of shares of Common Stock  proposed to be
registered  by it. The Company has no  obligation to reduce the number of shares
of Common Stock  proposed to be  registered  by it. The Company has the right to
delay,  suspend,  abandon or withdraw any offering  prior to the effective  date
thereof without liability to Carter,  provided such withdrawal is due to adverse
market  conditions  as determined  by the Company  after  consultation  with its
underwriters, if any.

     (b) In connection with any such  underwritten  offering,  the Company shall
agree to provide Carter and any underwriter  participating  in the  registration
and   distribution   of  such  shares  of  Common  Stock  with  such   customary
indemnification with respect to any liabilities arising out of or resulting from
any registration  statement,  prospectus or any amendment or supplement  thereto
relating  to any Shares;  provided,  that Carter  shall agree to  indemnify  the
Company as provided in Section 5(b).

     3. Holdback. Carter agrees not to effect any public sale or distribution of
any  shares  of  Common  Stock,  including  a sale  pursuant  to Rule 144 of the
Securities Act,  during a period up to 180-days  following the effective date of
any  registration  statement  covering  Common  Stock  (except  pursuant to such
registration  statement),  if and to the  extent  the  managing  underwriter  so
requests.

     4. Expenses. (a) "Registration Expenses" means all expenses, except Selling
Expenses  (as  defined  below),  incident  to the  Company's  performance  of or
compliance with its obligations pursuant to this Agreement and the completion of
transactions  relating thereto including,  without limitation,  all registration
and filing fees,  all fees and expenses of complying  with  securities  or "blue
sky" laws, all printing  expenses,  the fees and  disbursements of the Company's
independent  public  accountants,  including the expenses of any special audits,
reviews, compilations or other reports or information required by or incident to
such  performance  and  compliance,  and any fees or expenses of counsel for the
Company.

     (b) All  Registration  Expenses  incurred in  connection  with or otherwise
incident  to all  registrations  pursuant  to  Section  1 shall  be borne by the
Company and Carter pro rata on the basis of the number of shares of Common Stock
so registered by each of them,  whether or not any registration  statement filed
in connection  therewith ever becomes effective or any such sale or distribution
ever is consummated.

     (c) Carter will be solely  responsible  for (i) any fees or expenses of his
own counsel,  (ii) any expenses for the  preparation of financial  statements or
other data, other than financial  statements or other data normally  prepared by
the Company in the ordinary course of its business,  and (iii) any  underwriting
discounts  and  commissions   relating  to  the  Shares  being  sold  by  Carter
(collectively, "Selling Expenses").

     5.  Preparation;  Reasonable  Investigation  and  Further  Actions.  (a) In
connection  with the  preparation  and  filing  of such  registration  statement
registering  Shares under the  Securities  Act, the Company will give Carter and
his counsel and  accountant,  the  opportunity  to review and comment  upon such
registration  statement,  each  prospectus  included  therein  or filed with the
Securities  and  Exchange  Commission  (the  "Commission"),  and each  amendment
thereof or  supplement  thereto,  and will give him such access to its books and
records and such  opportunities  to discuss the business of the Company with its
officers and the independent public accountants who have certified its financial
statements as shall be  necessary,  in the  reasonable  opinion of the Company's



                                      -2-

<PAGE>

counsel and such underwriters,  to conduct a reasonable investigation within the
meaning of the Securities Act.

     (b) Carter will furnish the Company with such information regarding himself
and  the  distribution  of his  Shares  as the  Company  may  from  time to time
reasonably  request  and as shall be  required  by law or by the  Commission  in
connection with such  distribution.  In connection with the  registration of the
shares of Common  Stock as  contemplated  hereby,  Carter  will take all actions
which are  reasonably  necessary  or which may be  reasonably  requested  by the
Company or any underwriter participating in the registration and distribution of
such  shares of Common  Stock to effect the  registration  of such shares and to
facilitate the disposition  thereof in accordance with the plans of distribution
of the Company or any such  underwriter.  Carter will  indemnify the Company for
any liabilities arising out of or resulting from all such furnished  information
contained  in, and actions  taken with respect to, any  registration  statement,
prospectus or any amendment or supplement thereto relating to any Shares. 

     6. Entire  Agreement;  Binding  Effect;  Governing  Law. This Agreement (a)
shall be binding  upon and shall inure to the benefit of each of the parties and
their respective  successors and assigns,  provided,  however, that Carter shall
not assign this Agreement or any of his obligations  hereunder without the prior
written consent of the Company,  and (b) shall be governed by and interpreted in
accordance  with the laws of the State of New Jersey  (without  giving effect to
principles  of  conflicts  of laws)  and (c)  shall,  together  with the  Pledge
Agreement  dated as of the date hereof between the Company and Carter,  the Note
dated as of the date  hereof  between  the  Company  and  Carter  and the  Stock
Purchase  Agreement,  constitute the entire  agreement  between the parties with
respect to the subject  matter  hereof and thereof and will  supersede all prior
negotiations,  agreements  and  understandings  of the  parties  of any  nature,
whether oral or written, with respect to such subject matter.


     IN WITNESS WHEREOF, the parties have executed this Agreement as of the date
first above written.


                                             MERRIMAC INDUSTRIES, INC.
                              

                                             By: /s/ Robert V. Condon
                                                 --------------------
                                             Name: Robert V. Condon
                                             Title: Vice President, Finance and
                                                    Chief Financial Officer




                                                 /s/ Mason N. Carter
                                                 -------------------
                                                     Mason N. Carter





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