EXHIBIT 10.13
                                 AMENDMENT NO. 1

                                       TO

                           LOAN AND SECURITY AGREEMENT

     THIS AMENDMENT NO. 1 ("Amendment") is entered into as of February 27, 1998,
by and between  MPD  TECHNOLOGIES,  INC.,  a New York  corporation  ("Borrower")
having its principal place of business at 49 Wireless Boulevard,  Hauppauge, New
York and IBJ SCHRODER  BUSINESS  CREDIT  CORPORATION (as successor to IBJ BANK &
TRUST  COMPANY)  ("IBJS")  having its  principal  place of business at One State
Street, New York, New York and each of the other financial institutions named in
or which hereafter become a party to the Loan Agreement (as defined below) (IBJS
and such other financial institutions,  the "Lenders") and IBJS as agent for the
Lenders (IBJS in such capacity, the "Agent").

                                   BACKGROUND

     Borrower,  Agent and Lenders are parties to a Loan and  Security  Agreement
dated as of February 13, 1997 (as amended,  supplemented  or otherwise  modified
from time to time,  the "Loan  Agreement")  pursuant to which  Lenders  provided
Borrower with certain financial accommodations.

         Borrower has requested  that Lenders and Agent amend the Loan Agreement
to, among other things,  (a) increase the amount of the overall credit  facility
by providing for a $3,000,000  equipment loan facility,  (b) provide a procedure
to increase the Maximum  Revolving Amount upon repayment by Borrower of the Term
Loan and (c) extend the  termination  date, and Agent and Lenders are willing to
do so on the terms and conditions hereafter set forth.

     NOW, THEREFORE,  in consideration of any loan or advance or grant of credit
heretofore  or  hereafter  made to or for the  account of  Borrower by Agent and
Lenders,  and for  other  good  and  valuable  consideration,  the  receipt  and
sufficiency of which are hereby acknowledged, the parties hereto hereby agree as
follows:

     1.  Definitions.  All capitalized  terms not otherwise defined herein shall
have the meanings given to them in the Loan Agreement.

     2. Amendment to Loan  Agreement.  Subject to satisfaction of the conditions
precedent set forth in Section 3 below,  the Loan Agreement is hereby amended as
follows:

     2.1.  Section 1.2 of the Loan  Agreement is hereby amended by inserting the
following defined terms in their appropriate alphabetical order:


<PAGE>


     Amendment  No. 1 - means  Amendment  No. 1 to Loan and  Security  Agreement
     dated as of the Amendment No. 1 Effective Date among Borrower,  Lenders and
     Agent.

     Amendment No. 1 Effective Date - means February 27, 1998.

     Capex Loans - the loans made by Lenders as  provided  in Section  2.3(B) of
     this Agreement.

     Capex Note - the  secured  promissory  note to be  executed  by Borrower to
     evidence  the Capex  Loans,  which  shall be in the form of Exhibit  2.3(B)
     attached to Amendment No. 1.

     Maximum Capex Amount -Three Million  Dollars  ($3,000,000),  less principal
     payments of the Capex Loans.

     2.2.  Section 1.2 of the Loan  Agreement is hereby  amended by amending the
following defined terms in their entirety to provide as follows:

     Loans - all loans and advances made by Lenders  pursuant to this Agreement,
     including,  without limitation, all Revolving Credit Loans, Capex Loans and
     the Term Loan.

     Maximum  Revolving  Amount  - the  lesser  of (a)  Twelve  Million  Dollars
     ($12,000,000)  or (b) sum of (i) Ten Million Three Hundred Thousand Dollars
     ($10,300,000)  plus (ii)  commencing  with the March 1, 1998  payment,  the
     amount paid by Borrower  each month with  respect to the  principal  of the
     Term Loan.

     Notes - the Term Note, the Capex Note and the Revolving Credit Note.

     2.3 The preamble of Section 2 of the Loan  Agreement  is hereby  amended by
deleting  the  phrase  "THIRTEEN  MILLION  AND  XX/100  DOLLARS   ($13,000,000)"
appearing in the fourth and fifth lines thereof and replacing it with the phrase
"FIFTEEN  MILLION FOUR HUNDRED FIFTY THOUSAND AND XX/100  ($15,450,000)"  in its
place and stead.

     2.4.  Section 2.3 of the Loan  Agreement is hereby  amended by (a) deleting
the section  heading "Term Loan" and replacing it with the section heading "Term
Loan and Capex Loans" in its place and stead, (b) inserting an "(A)" immediately
before the word "Subject"  appearing in the first line thereof and (c) inserting
a new subsection "(B)" at the end thereof as follows:

          "(B) Capex Loans.  (i) Subject to the terms and  conditions  set forth
     herein,  each Lender,  severally  and not jointly,  agrees to make Loans to
     Borrower to finance Borrower's  purchase of Equipment for use in Borrower's
     business  ("Capex  Loans")  in the sum  equal to such  Lender's  Commitment
     Percentage  of an amount  not to  exceed  eighty  percent  (80%) of the net
     invoice  cost of such  Equipment  purchased  by  Borrower  (which  shall be
     exclusive of shipping,  handling,  taxes, installation and all other "soft"
     costs) provided that the total amount of all outstanding  Capex Loans shall
     not exceed the Maximum  Capex  Amount.  All Capex Loans must be in original
     principal amounts


<PAGE>


     of not less than  $100,000.  Capex Loans may only be borrowed  prior to the
     first  anniversary of the Amendment No. 1 Effective  Date.  Once repaid,  a
     Capex Loan may not be reborrowed.  The Capex Loan shall be evidenced by and
     subject to the terms of a secured  promissory  note, in  substantially  the
     form attached hereto as Exhibit 2.3(B) (the "Capex Note").

          (ii) Loans  constituting  Capex Loans shall be accumulated during each
     of twelve  periods  (each a  "Borrowing  Period")  during  the  Term.  Each
     Borrowing Period shall consist of one month with the first Borrowing Period
     commencing on the  Amendment  No. 1 Effective  Date and ending on March 26,
     1998. At the end of each Borrowing Period,  the sum of the principal amount
     of all Capex Loans made during such  Borrowing  Period will be amortized on
     the basis of a sixty  (60)  month  amortization  schedule  (such  amount as
     determined  with  respect  to  any  Borrowing  Period,   the  "Amortization
     Amount").  Monthly principal payments will be initially  determined for the
     Capex Loans made during the initial Borrowing Period and the amount of such
     monthly  principal  payments shall be increased upon the completion of each
     subsequent  Borrowing  Period  by the  Amortization  Amount  for each  such
     subsequent  Borrowing  Period.  Each Capex Loan shall be,  with  respect to
     principal,   payable  in  equal   monthly   installments   based  upon  the
     amortization schedule set forth above, commencing on the first Business Day
     of the month  following  the month in which such Capex Loan was made and on
     the first day of each month  thereafter,  subject to acceleration  upon the
     occurrence  and  continuance of an Event of Default under this Agreement or
     termination of this Agreement.  Each Lender's Commitment  Percentage of the
     Capex Loans shall be evidenced by and subject to the Capex Note."

     2.5.  Section 2.6 of the Loan  Agreement is hereby  amended by deleting the
amount "$500,000"  appearing in the fifth line thereof and replacing it with the
amount "$2,650,000" in its place and stead.

     2.6.  Section  2.16(A) of the Loan Agreement is hereby amended by inserting
the following sentence at the end thereof:

     "The Capex Loans shall be advanced according to the Commitment  Percentages
     of Lenders."

     2.7.  Section 2.16(B) of the Loan Agreement is hereby amended by adding the
following sentence immediately after the second sentence thereof:

     "Each payment  (including  each  prepayment)  by Borrower on account of the
     principal of and  interest on the Capex Note,  shall be made from or to, or
     applied to that portion of the Capex Loans  evidenced by the Capex Note pro
     rata according to the Commitment Percentages of Lenders."

     2.8.  Section  3.1(A) of the Loan  Agreement is hereby amended by inserting
the phrase "plus the Capex Loans"  immediately  after the phrase "the Term Loan"
appearing in the third line thereof.

                                     Page 3

<PAGE>


     2.9. Section 3.1(D) of the Loan Agreement is hereby amended by deleting the
first  sentence in its entirety and replacing it with the following in its place
and stead:

     "Borrower  shall pay an unused  facility fee at the rate of  one-quarter of
     one  percent  (1/4%) per annum on the  difference  between  (a) the Maximum
     Revolving Amount plus (i) from February 27, 1998 through February 28, 1999,
     the Maximum Capex Amount or (ii) at any time thereafter, the unpaid balance
     of the Capex Loans and (b) the average  daily unpaid  balance of the Loans,
     payable to Agent for the ratable  benefit of Lenders  quarterly in arrears,
     commencing on the first day of the calendar quarter  following the calendar
     quarter in which the Closing Date occurs."

     2.10.  Section 3.2 of the Loan  Agreement is hereby amended by deleting the
phrase  "February 12, 2000"  appearing in the fourth and fifth lines thereof and
replacing it with the phrase "February 12, 2001" in its place and stead.

     2.11.  Section  3.3(C) of the Loan Agreement is hereby amended by inserting
the phrase "plus the Maximum  Capex  Amount"  immediately  after the phrase "the
Maximum Revolving Amount" appearing in the eighth and twelfth lines thereof.

     2.12.  Section  3.3(D) of the Loan Agreement is hereby amended by inserting
the phrase  "and the Capex  Loans"  immediately  following  the phrase "the Term
Loan" appearing in the second sentence thereof.

     2.13.  Section 3.5 of the Loan Agreement is hereby amended by inserting the
phrase  "and/or the Capex  Loans"  immediately  after the phrase "the Term Loan"
appearing in the sixteenth line thereof.

     2.14.  Section 9.3 of the Loan  Agreement is hereby amended by deleting the
phrase "Fixed Charge Ratio" appearing in the fifth line thereof and replacing it
with "Fixed Charge Coverage ratio" in its place and stead.

     2.15.  Section 10 of the Loan  Agreement  is hereby  amended to include the
following new subsection 10.3 at the end thereof:

          "10.3. Conditions to Each Capex Loan. The agreement of Lenders to make
     any Capex Loan is  subject  to  satisfaction  of the  following  conditions
     precedent:  (a) receipt by Agent of (i) a copy of the  invoice  relating to
     the Equipment being  purchased,  (ii) evidence that such Equipment has been
     shipped to Borrower,  (iii) evidence that the requested Capex Loan does not
     exceed  eighty  percent  (80%) of the net  invoice  cost of such  Equipment
     purchased by Borrower  (which  shall be  exclusive  of shipping,  handling,
     taxes,  installation  and all other  "soft"  costs),  and (iv)  such  other
     documentation  and evidence  that Agent may  request;  and (b) after giving
     effect thereto, the aggregate  outstanding Capex Loans shall not exceed the
     Maximum Capex Amount."

                                     Page 4

<PAGE>


     2.16. Section 13.12 of the Loan Agreement is hereby amended to by inserting
the phrase "and the Capex Loans"  immediately after the phrase "Revolving Credit
Loan" appearing in the last line thereof.

     2.17.  Exhibit 2.1 to the Loan  Agreement is hereby deleted and replaced in
its entirety with Exhibit 2.1 attached to Amendment No. 1.

     3. Conditions of Effectiveness.  This Amendment shall become effective upon
satisfaction of the following  conditions  precedent:  Agent shall have received
(i) four (4) copies of this  Amendment  executed by Borrower and  consented  and
agreed to by Microwave Power Devices, Inc., as guarantor,  (ii) an amendment fee
to Agent equal to  $15,000,  (iii) an executed  Amended and  Restated  Revolving
Credit  Note,  (iv) an  executed  Capex  Note  and (v)  evidence  in the form of
corporate resolutions demonstrating that Borrower shall have taken all necessary
corporate action for the authorization,  execution,  delivery and performance of
this  amendment  and  (vi)  such  other  certificates,  instruments,  documents,
agreements  and  opinions of counsel as may be required by Agent or its counsel,
each of which  shall  be in form and  substance  satisfactory  to Agent  and its
counsel.

     4. Representations and Warranties.  Borrower hereby represents and warrants
as follows:

          (a)  This  Amendment  and  the  Loan  Agreement,  as  amended  hereby,
     constitute  legal,  valid  and  binding  obligations  of  Borrower  and are
     enforceable against Borrower in accordance with their respective terms.

          (b)  Upon  the  effectiveness  of  this  Amendment,   Borrower  hereby
     reaffirms all covenants,  representations  and warranties  made in the Loan
     Agreement to the extent the same are not amended  hereby and agree that all
     such covenants, representations and warranties shall be deemed to have been
     remade as of the effective date of this Amendment.

          (c) No Event of Default or Default has occurred and is  continuing  or
     would exist after giving effect to this Amendment.

          (d)  Borrower has no defense,  counterclaim  or offset with respect to
     the Loan Agreement.

     5. Effect on the Loan Agreement.

     (a) Upon the  effectiveness  of this Amendment,  each reference in the Loan
Agreement to "this Agreement,"  "hereunder," "hereof," "herein" or words of like
import shall mean and be a reference to the Loan Agreement as amended hereby.

     (b) Except as  specifically  amended herein,  the Loan  Agreement,  and all
other  documents,  instruments  and  agreements  executed  and/or  delivered  in
connection  therewith,  shall  remain in full force and  effect,  and are hereby
ratified and confirmed.

                                     Page 5

<PAGE>


     (c) The execution,  delivery and  effectiveness of this Amendment shall not
operate as a waiver of any right,  power or remedy of Agent,  nor  constitute  a
waiver  of any  provision  of  the  Loan  Agreement,  or  any  other  documents,
instruments  or  agreements  executed  and/or  delivered  under or in connection
therewith.

     6.  Governing  Law. This  Amendment  shall be binding upon and inure to the
benefit of the parties  hereto and their  respective  successors and assigns and
shall be governed by and construed in  accordance  with the laws of the State of
New York.

     7. Headings.  Section  headings in this  Amendment are included  herein for
convenience  of reference only and shall not constitute a part of this Amendment
for any other purpose.

     8. Counterparts;  Telecopied Signatures.  This Amendment may be executed in
any number of and by different parties hereto on separate  counterparts,  all of
which, when so executed,  shall be deemed an original, but all such counterparts
shall constitute one and the same agreement.  Any signature delivered by a party
by facsimile transmission shall be deemed to be an original signature hereto.

     IN WITNESS WHEREOF, this Amendment has been duly executed as of the day and
year first written above.

                                    MPD TECHNOLOGIES, INC.


                                    By: /s/ Paul E. Donofrio
                                        -----------------------------
                                    Name: Paul E. Donofrio
                                    Title: V.P. Finance/CFO


                                    IBJ SCHRODER BUSINESS CREDIT CORPORATION, 
                                      as Agent and a Lender


                                    By: /s/ Alfred J. Scoyni
                                       -------------------------------
                                    Name: Alfred J. Scoyni
                                    Title: Vice President

CONSENTED AND AGREED TO:

MICROWAVE POWER DEVICES, INC.


By: /s/ Paul E. Donofrio
    -----------------------------
Name: Paul E. Donofrio
Title: V.P. Finance/CFO

                                     Page 6

<PAGE>


                                   EXHIBIT 2.1

                              AMENDED AND RESTATED
                              REVOLVING CREDIT NOTE


$12,000,000.00                                           New York, New York
                                                         as of February 27, 1998


     This Revolving  Credit Note is executed and delivered under and pursuant to
the terms of that certain Loan and Security  Agreement  dated as of February 13,
1997 (as the same has been and may be further amended,  supplemented or modified
from time to time, the "Loan Agreement") by and among MPD TECHNOLOGIES,  INC., a
New York corporation having its chief executive office at 49 Wireless Boulevard,
Hauppauge,  New York  11788  ("Borrower"),  IBJ  SCHRODER  BANK & TRUST  COMPANY
("IBJS"),  each of the other financial  institutions named in or which hereafter
become   parties  to  the  Loan  Agreement   (IBJS  and  such  other   financial
institutions,  the  "Lenders")  and IBJS as agent for the Lenders  (IBJS in such
capacity,  "Agent").  Capitalized  terms not otherwise defined herein shall have
the meanings as provided in the Loan Agreement.

     FOR VALUE  RECEIVED,  Borrower hereby promises to pay to the order of Agent
for the  ratable  benefit of Lenders  at  Agent's  offices  located at One State
Street,  New York,  New York 10004 or at such other place as Agent may from time
to time designate in writing to Borrower:

     (i) the principal sum of TWELVE MILLION AND 00/100 DOLLARS ($12,000,000.00)
or, if different from such amount,  such amount of Revolving  Advances as may be
due and  owing  under  the  Loan  Agreement,  payable  in  accordance  with  the
provisions of the Loan Agreement and subject to acceleration upon the occurrence
of an Event of Default under the Loan Agreement, earlier termination of the Loan
Agreement or earlier prepayment as required pursuant to the terms thereof; and

     (ii)  interest  on the  principal  amount  of this  Note  from time to time
outstanding  until such principal amount is paid in full, at such interest rates
and at such  times as are  provided  in the Loan  Agreement.  Upon and after the
occurrence of an Event of Default, and during the continuation thereof, interest
shall be payable at the  Default  Rate.  In no event,  however,  shall  interest
hereunder exceed the maximum interest rate permitted by law.

     This Amended and Restated  Revolving Credit Note amends and restates in its
entirety  and is given in  substitution  for, but not in  satisfaction  of, that
certain  Revolving  Credit  Note dated  February  13, 1997 issued by Borrower in
favor of Agent for the  ratable  benefit of Lenders  in the  original  principal
amount of $10,300,000.

     This Note is the Revolving  Credit Note  referred to in the Loan  Agreement
and is secured,  inter alia, by the liens granted pursuant to the Loan Agreement
and the Other


<PAGE>


Agreements,  is entitled to the  benefits  of the Loan  Agreement  and the Other
Agreements and is subject to all of the agreements, terms and conditions therein
contained.

     This  Note is  subject  to  mandatory  prepayment  and  may be  voluntarily
prepaid,  in whole or in part, on the terms and conditions set forth in the Loan
Agreement.

     If an Event of  Default  under  Sections  11.1(J)  or  11.1(K)  of the Loan
Agreement shall occur, then this Note shall immediately  become due and payable,
without  notice,  together with  reasonable  attorneys'  fees if the  collection
hereof  is  placed in the hands of an  attorney  to  obtain or  enforce  payment
hereof.  If any other Event of Default  shall occur under the Loan  Agreement or
any of the Other  Agreements  which is not cured  within  any  applicable  grace
period, then this Note may, as provided in the Loan Agreement, be declared to be
immediately due and payable, without notice, together with reasonable attorneys'
fees, if the  collection  hereof is placed in the hands of an attorney to obtain
or enforce payment hereof.

     This  Note is being  delivered  in the  State  of New  York,  and  shall be
construed and enforced in accordance with the laws of such State.

     Borrower  expressly  waives any  presentment,  demand,  protest,  notice of
protest,  or  notice  of any  kind  except  as  expressly  provided  in the Loan
Agreement.

                                            MPD TECHNOLOGIES, INC.


                                            By: /s/ Paul E. Donofrio
                                                ---------------------------
                                            Name:  Paul E. Donofrio
                                            Title: Vice President

STATE OF NEW YORK   )
                    :  ss.:
COUNTY OF NEW YORK  )

     On the 2nd day of March, 1998, before me personally came Paul Donofrio,  to
me known,  who being by me duly  sworn,  did  depose and say that he is the Vice
President of MPD  Technologies,  Inc.,  the  corporation  described in and which
executed the foregoing  instrument;  and that he was authorized to sign his name
thereto.


                                            /s/ Lisa M. Vaccaro
                                            -------------------------------
                                                Notary Public

                                            Lisa M. Vaccaro
                                            Notary Public, State of New York
                                            No. 02VA5049635
                                            Qualified in Nassau County
                                            Commission Expires 9/18/99


                                     Page 8

<PAGE>


                                 EXHIBIT 2.3(B)

                                   CAPEX NOTE


$3,000,000.00                                            New York, New York
                                                         as of February 27, 1998


     This Capex Note is executed and  delivered  under and pursuant to the terms
of that certain Loan and  Security  Agreement  dated as of February 13, 1997 (as
the same has been and may be further amended, supplemented or modified from time
to time, the "Loan Agreement") by and among MPD  TECHNOLOGIES,  INC., a New York
corporation  having  its  chief  executive  office  at  49  Wireless  Boulevard,
Hauppauge,  New York  11788  ("Borrower"),  IBJ  SCHRODER  BANK & TRUST  COMPANY
("IBJS"),  each of the other financial  institutions named in or which hereafter
become   parties  to  the  Loan  Agreement   (IBJS  and  such  other   financial
institutions,  the  "Lenders")  and IBJS as agent for the Lenders  (IBJS in such
capacity,  "Agent").  Capitalized  terms not otherwise defined herein shall have
the meanings as provided in the Loan Agreement.

     FOR VALUE  RECEIVED,  Borrower hereby promises to pay to the order of Agent
for the  ratable  benefit  of Lender at  Agent's  offices  located  at One State
Street,  New York,  New York 10004 or at such other place as Agent may from time
to time designate to Borrower in writing:

     (i) the principal sum of THREE MILLION AND 00/100  DOLLARS  ($3,000,000.00)
or such lesser  amount as shall be advanced by Lender on or before  February 28,
1999,  payable in consecutive  monthly  installments  each in an amount equal to
Lender's Commitment  Percentage of the applicable monthly payment on Capex Loans
as set forth in the Loan Agreement,  subject to acceleration upon the occurrence
of an Event of Default under the Loan Agreement, earlier termination of the Loan
Agreement or earlier  prepayment  as required  pursuant to the terms of the Loan
Agreement; and

     (ii)  interest  on the  principal  amount  of this  Note  from time to time
outstanding  until such principal amount is paid in full, at such interest rates
and at such  times as are  provided  in the Loan  Agreement.  Upon and after the
occurrence of an Event of Default, and during the continuation thereof, interest
shall be payable at the  Default  Rate.  In no event,  however,  shall  interest
hereunder exceed the maximum interest rate permitted by law.

     This  Note is the  Capex  Note  referred  to in the Loan  Agreement  and is
secured, inter alia, by the liens granted pursuant to the Loan Agreement and the
Other  Agreements,  is entitled to the  benefits of the Loan  Agreement  and the
Other  Agreements and is subject to all of the agreements,  terms and conditions
therein contained.

     This  Note is  subject  to  mandatory  prepayment  and  may be  voluntarily
prepaid,  in whole or in part, on the terms and conditions set forth in the Loan
Agreement.

                                     Page 9

<PAGE>


     If an Event of  Default  under  Sections  11.1(J)  or  11.1(K)  of the Loan
Agreement shall occur, then this Note shall immediately  become due and payable,
without  notice,  together with  reasonable  attorneys'  fees if the  collection
hereof  is  placed in the hands of an  attorney  to  obtain or  enforce  payment
hereof.  If any other Event of Default  shall occur under the Loan  Agreement or
any of the Other  Agreements,  which is not cured  within any  applicable  grace
period, then this Note may, as provided in the Loan Agreement, be declared to be
immediately due and payable, without notice, together with reasonable attorneys'
fees, if the  collection  hereof is placed in the hands of an attorney to obtain
or enforce payment hereof.

     This Note is being delivered in the State of New York, and shall be
construed and enforced in accordance with the laws of such State.

     Borrower  expressly  waives any  presentment,  demand,  protest,  notice of
protest,  or  notice  of any  kind  except  as  expressly  provided  in the Loan
Agreement.


                                            MPD TECHNOLOGIES, INC.


                                            By By: /s/ Paul E. Donofrio
                                                   -----------------------
                                            Name: Paul E. Donofrio
                                            Title: Vice President


STATE OF NEW YORK  )
                   :  ss.:
COUNTY OF NEW YORK )

     On the 2nd day of March, 1998, before me personally came Paul Donofrio,  to
me known,  who being by me duly  sworn,  did  depose and say that he is the Vice
President of MPD  Technologies,  Inc.,  the  corporation  described in and which
executed the foregoing instrument;  and that he signed his name thereto by order
of the board of directors of said corporation.


                                         /s/ Lisa M. Vaccaro
                                         --------------------------------
                                               Notary Public

                                         Lisa M. Vaccaro
                                         Notary Public, State of New York
                                         No. 02VA5049635
                                         Qualified in Nassau County
                                         Commission Expires 9/18/99

                                    Page 10