EXHIBIT 10.5
                                FIRST AMENDMENT
                                       TO
                     AMENDED AND RESTATED CREDIT AGREEMENT


                  FIRST   AMENDMENT,   dated  as  of   August   14,   1995  (the
'Amendment'),  to the Amended and Restated Credit  Agreement,  dated as of April
12, 1995, among NAI Technologies,  Inc., a New York corporation (the 'Company'),
Chemical  Bank, a New York  banking  corporation  ('Chemical'),  The Bank of New
York, a New York banking  corporation  ('BNY'),  and each of the other financial
institutions  which  from time to time  becomes  party  thereto  (together  with
Chemical and BNY, the 'Banks'),  BNY, as administrative agent (in such capacity,
the 'Administrative Agent') and Chemical, as collateral agent (in such capacity,
the 'Collateral Agent').


                             W I T N E S S E T H :


                  WHEREAS,  the Company, the Banks, the Administrative Agent and
the  Collateral  Agent are parties to that certain  Amended and Restated  Credit
Agreement,  dated as of April 12, 1995 (as may  hereafter be amended,  modified,
supplemented or restated, the 'Credit Agreement');

                  WHEREAS, unless otherwise defined herein, terms defined in the
Credit Agreement and used herein are used herein as therein defined; and

                  WHEREAS,  the Company has  requested and the Banks have agreed
to, among other things, waive compliance with certain financial covenants and to
defer the payment of certain principal amounts due under the Credit Agreement as
hereinafter set forth.

                  Accordingly, the parties hereto hereby agree as follows:

                  Section 1.  Deferral.  The Banks hereby agree to defer each of
the principal  payments in the amount of $875,000 which are scheduled to be made
on each of September  30, 1995 and  December  31, 1995  pursuant to the terms of
Section 2.08(b) of the Credit Agreement to the Maturity Date.

                  Section  2.  Confirmation  of   Inapplicability   of  Extended
Maturity Date. The Company hereby confirms that the right to unilaterally extend
the maturity of the Loans to the Extended Maturity Date has expired, and further
confirms that the Loans shall mature on the Maturity Date or earlier as provided
in the Credit Agreement.







                  Section 3.   Limited  Waiver of Financial Covenants. The Banks
hereby agree to waive compliance with certain provisions of the Credit Agreement
as follows:

                           (a) Compliance with the financial  covenant set forth
         in Section 6.14 is hereby waived for the fiscal  quarter ended June 30,
         1995;  provided  that the  Consolidated  Current  Ratio for such period
         shall not be less than .95 to 1.

                           (b) Compliance with the financial  covenant set forth
         in Section 6.15 is hereby waived for the fiscal  quarter ended June 30,
         1995;  provided that the Consolidated Quick Ratio for such period shall
         not be less than .48 to 1.

                           (c) Compliance with the financial  covenant set forth
         in  Section  6.16 is hereby  waived  for each of the one month  periods
         ending March 31, 1995,  April 30, 1995 and May 31, 1995,  provided that
         Consolidated Tangible Net Worth for such periods shall not be less than
         $3,600,000 at any time during such periods.

                  Section 4.  Amendments to Article VI. Article VI of the Credit
Agreement is hereby amended as follows:

                  a.       Section 6.14 is hereby amended in its entirety to
         read as follows:

                           SECTION 6.14.  Maintenance  of  Consolidated  Current
         Ratio. Permit the Consolidated Current Ratio to fall below 1.00 to 1.00
         at the end of any fiscal  quarter  during the period  from the  Closing
         Date to June 30, 1995 and .91 to 1.00 at the end of any fiscal  quarter
         during the period from July 1, 1995 to December 31, 1995.

                  b.       Section 6.15 is hereby amended in its entirety to
         read as follows:

                           SECTION  6.15.   Maintenance  of  Consolidated  Quick
         Ratio.  Permit the  Consolidated  Quick Ratio to fall below (i) 0.45 to
         1.00 at the end of any  fiscal  quarter  during  the  period  from  the
         Closing  Date to June 30,  1995 or (ii)  0.42 to 1.00 at the end of any
         fiscal  quarter  ending during the period from July 1, 1995 to December
         31, 1995.

                  c.       Section 6.16 is hereby amended in its entirety to
         read as follows:

                           SECTION 6.16.   Maintenance of Consolidated Tangible
         Net Worth.  Permit Consolidated Tangible Net Worth for the

                                       2





         following  periods to fall below the  amount  set forth  opposite  such
         period at any time during such periods:



                  Period                                               Amounts
                  ------                                               -------
                                                                      
                  March 1, 1995                                       $7,400,000
                    through March 31, 1995
                  April 1, 1995                                        7,000,000
                    through April 30, 1995
                  May 1, 1995                                          6,900,000
                    through May 31, 1995
                  June 1, 1995 through                                 2,250,000
                    November 30, 1995
                  December 1, 1995 through                             2,600,000
                    the Maturity Date


                  Section 5. Further Obligations.  The Company shall furnish to
the  Banks  on  or  before  October 31, 1995 a liquidation analysis with respect
to the  assets  of the  Company  and its  Subsidiaries,  which  report  shall be
reviewed by, and prepared in consultation with,  Policano and Manzo.  Failure of
the  Company to furnish  such  report to the Bank when due shall  constitute  an
immediate Event of Default.

                  Section 6. Amendment Fee. In order to induce each of the Banks
to execute and deliver this  Amendment,  the Company hereby agrees that it shall
pay to the Collateral  Agent for the account of the Banks a fee equal to $50,000
(the 'Amendment Fee') on or before the Maturity Date.

                  Section 7. Representations and Warranties. The representations
and  warranties  set forth in  Section 3 of the  Credit  Agreement  are true and
correct in all  material  respects on and as of the date  hereof,  except to the
extent that such  representations and warranties  expressly relate to an earlier
date. As of the Effective  Date, and after giving effect to this  Amendment,  no
Event of Default,  or an event with which the giving of notice or the passage of
time, or both, would constitute an Event of Default, exists.

                  Section 8.  Counterparts.  This Amendment may be executed in 
any number  of  counterparts,  each  of  which shall constitute an original and
all of which when taken together shall constitute one and the same instrument.

                  Section 9.  Conditions to Effectiveness.  This Amendment shall
become  effective  upon  the  execution  of  this Amendment by the Company, the 
Administrative Agent, the Collateral Agent and the

                                       3





Banks (and the receipt by the Collateral Agent of evidence satisfactory to it of
such execution) (the 'Effective Date').

                  Section 10. Ratification. Except to the extent hereby amended,
the Credit Agreement remains in full force and effect and is hereby ratified and
affirmed.  References in the Loan Documents to the Credit  Agreement  shall mean
such document as amended by this Amendment,  as the same may be further amended,
supplemented or otherwise modified from time to time.

                  Section 11. Costs and  Expenses.  All  out-of-pocket  expenses
incurred  by the Banks,  including  the  reasonable  fees and  disbursements  of
Zalkin,  Rodin & Goodman LLP, counsel to the Banks,  incurred in connection with
the  negotiation  and preparation of this Amendment shall be paid by the Company
as provided in Subsection 9.05 of the Credit Agreement.

                  Section  12.  References.  This  Amendment  shall  be  limited
precisely  as  written  and  shall not be  deemed  (a) to be a  consent  granted
pursuant to, or a waiver or modification  of, any other term or condition of the
Credit Agreement or any of the instruments or agreements  referred to therein or
(b) to prejudice any right or rights which the Administrative Agent,  Collateral
Agent or the Banks  may now have or have in the  future  under or in  connection
with the Credit  Agreement or the Loan  Documents or any of the  instruments  or
agreements referred to therein.

                  Section  13.  Applicable  Law.  THIS  AMENDMENT  SHALL  IN ALL
RESPECTS BE CONSTRUED IN  ACCORDANCE  WITH AND GOVERNED BY THE LAWS OF THE STATE
OF NEW YORK APPLICABLE TO CONTRACTS MADE AND TO BE PERFORMED  WHOLLY WITHIN SUCH
STATE.

                  Section 14.  Headings.  Section headings in this Amendment are
included  herein  for  convenience  of  reference only and are not to affect the
construction  of,  or to be  taken  into  consideration  in  interpreting,  this
Amendment.

                  Section 15. Integration.  This Amendment represents the entire
agreement  of the parties  hereto with  respect to the  amendment  of the Credit
Agreement  and the terms of any letters  and other  documentation  entered  into
among the Company  and any Bank or the  Administrative  Agent or the  Collateral
Agent prior to the execution of this Amendment  which relate to the amendment of
the Credit Agreement shall be replaced by the terms of this Amendment.


                                       4





                  IN WITNESS  WHEREOF,  the  parties  hereto  have  caused  this
Amendment  to be duly  executed  and  delivered  in New York,  New York by their
proper and duly authorized officers as of the day and year first above written.

                                           NAI TECHNOLOGIES, INC.

                                           By___________________________
                                             Title:

                                           THE BANK OF NEW YORK
                                           as Administrative Agent and as a Bank

                                           By:___________________________
                                              Vice President

                                           CHEMICAL BANK
                                           as Collateral Agent and as a Bank

                                           By:___________________________
                                              Vice President

Consented to as of this
14th day of August, 1995

NAI TECHNOLOGIES - SYSTEMS DIVISION CORPORATION

By:_______________________
   Title:

WILCOM, INC.

By:_______________________
   Title:

ARATHON, V.I., INC.

By:_______________________
   Title:

CODAR TECHNOLOGY, INC.

By:_______________________
   Title:

                                       5