<PAGE>   1
                                                                   EXHIBIT 10.10

                                    AMENDMENT
                          EFFECTIVE SEPTEMBER 25, 1998
                                       TO
                             ORIGINAL LOAN AGREEMENT
                                      AMONG
                                NATIONSBANK, N.A.
        (SUCCESSOR BY MERGER TO THE BOATMEN'S NATIONAL BANK OF ST. LOUIS)
                                       AND
                                 LABARGE, INC.,
                             LABARGE/STC, INC., AND
                             LABARGE WIRELESS, INC.


An AMENDMENT to LOAN AGREEMENT (this "Amendment") by and among LABARGE, INC.,
LABARGE/STC, INC., and LABARGE WIRELESS, INC.(collectively and separately,
"Borrower") and NATIONSBANK, N.A. (successor by merger to The Boatmen's National
Bank of St. Louis) ("Bank").

                                    RECITALS:

A.    Borrower and Bank are parties to that certain Loan Agreement dated as of
      June 25, 1996, as amended prior to the effective date hereof (the 
      "Original Loan Agreement").

B.    Borrower has requested that Bank reduce the Revolving Commitment and
      increase the Term Commitment under the Original Loan Agreement and make
      certain other changes to the provisions of the Original Loan Agreement.
      Bank is willing to do so subject to, and in reliance upon, the terms and
      conditions contained herein.



Therefore, in consideration of the mutual agreements herein and other sufficient
consideration, the receipt of which is hereby acknowledged, Borrower and Bank
hereby amend the Original Loan Agreement as follows:

1.    DEFINITIONS. Capitalized terms used and not otherwise defined herein have
the meanings given them in the Original Loan Agreement.

2.    EFFECTIVE DATE; UP-FRONT FEE. This Amendment shall become effective as of
September 25, 1998, (the "Effective Date") provided that Borrower has paid to
Lender an up-front fee of $13,750 in consideration of the increase in the Term
Commitment provided by this Amendment and has delivered to Lender an amended and
restated Revolving Note in the form of Exhibit A hereto and an amended and
restated Term Note in the form of Exhibit B hereto.

3.    AMENDMENTS TO ORIGINAL LOAN AGREEMENT.

      3.1.     REDUCTION IN REVOLVING LOAN COMMITMENT. Section 3.1.1 of the 
Original Loan Agreement is amended to read in its entirety as follows:

      "Subject to the limitations in Section 3.1.2 and elsewhere herein, Lender
      commits to make available from the Effective Date to the Maturity Date, a
      revolving credit facility of $15,000,000, or such lesser Dollar amount to
      which it may have been changed as provided herein, available as Revolving
      Advances made from time to time as provided herein. Subject to the
      limitations in Section 3.1.2 and elsewhere herein, payments and
      prepayments that are applied to reduce the Revolving Loans may be



<PAGE>   2


      reborrowed. Borrower may reduce the Revolving Commitment in whole
      multiples of $1,000,000 at any time and from time to time, but only if (i)
      Borrower gives Lender written notice of Borrower's intention to make such
      reduction at least one Business Day prior to the effective date of the
      reduction, and (ii) Borrower makes on the effective date of the reduction
      any payment on the Revolving Loan required under Section 7.3 as a
      consequence of the reduction. Any such reduction of the Revolving
      Commitment shall be permanent."

      3.2.     INCREASE IN TERM LOAN COMMITMENT. Section 3.2.1 of the Original
Loan Agreement is amended by replacing the amount of $4,000,000 with the amount
of $11,000,000.

      3.3.     EXTENSION OF MATURITIES; SCHEDULED PAYMENTS. Sections 6.1 and 6.3
of the Original Loan Agreement are amended to read in their entirety as follows:

      "        6.1.   MATURITY DATES. Borrower shall repay the Revolving Loan 
      and all unpaid accrued interest thereon on February 1, 2001. Borrower
      shall repay the Term Loan and all unpaid accrued interest thereon on
      September 15, 2005."

      "        6.3.   PRINCIPAL PAYMENTS ON TERM LOAN BEFORE MATURITY DATE. 
      Borrower shall make consecutive quarterly installment payments of
      principal on the Term Loan on December 31, 1998, and on the last day of
      each calendar quarter thereafter until the Maturity Date. The amount of
      each principal installment shall be $392,857."

      3.4.     CBR DECREMENTS AND LIBOR INCREMENTS. Section 4.3 of the Loan
Agreement is amended by deleting the table therein and replacing it with the
following table:

<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------
If the ratio of Funded Debt                The LIBOR Increment           the CBR Decrement      
to EBITDA is:                                        shall be:                   shall be:
---------------------------------------------------------------------------------------------
                                          for each       for the      for each       For the
                                         Revolving     Term Loan     Revolving     Term Loan
                                              Loan                        Loan
------------------------------------ -------------- ------------- ------------- -------------
<S>                                          <C>          <C>            <C>          <C>   
Greater  than or  equal  to 2.50 to          2.50%        2.825%        -0.00%       +0.125%
1.00
------------------------------------ -------------- ------------- ------------- -------------
Less than 2.50 to 1.00 and  greater          2.00%        2.125%        -0.25%       -0.125%
than or equal to 2.00 to 1.00
------------------------------------ -------------- ------------- ------------- -------------
Less than 2.00 to 1.00 and  greater          1.75%        1.875%        -0.50%       -0.375%
than or equal to 1.75 to 1.00
------------------------------------ -------------- ------------- ------------- -------------
Less than 1.75 to 1.00 and  greater          1.25%        1.375%        -1.00%       -0.625%
than or equal to 1.50 to 1.00
------------------------------------ -------------- ------------- ------------- -------------
Less than 1.50 to 1.00 and  greater          1.00%        1.125%        -1.25%       -0.875%
than or equal to 1.25 to 1.00
------------------------------------ -------------- ------------- ------------- -------------
Less than 1.25 to 1.00                       0.75%        0.875%        -1.50%       -1.125%
------------------------------------ -------------- ------------- ------------- -------------
</TABLE>
 

                                        2

<PAGE>   3

      3.5.     PERMITTED INDEBTEDNESS. A new section 15.2.6 is added to the
Original Loan Agreement as follows:

      "15.2.6. The Indebtedness of Borrower to the Arkansas Development Finance
      Authority with respect to the expansion of Borrower's plant in Berryville,
      Arkansas."

      3.6.     CERTAIN DEFINITIONS. The definitions of "Fixed Charges" and
"Interest" in Section 16.1 of the Original Loan Agreement are amended to read in
their entirety as follows:

      "Fixed Charges" means, for any period of calculation, the sum of (i)
      interest expense, (ii) the sum of all scheduled principal payments on any
      Indebtedness of Borrower (including the Loans, (iii) federal, state and
      local income tax expense, (iv) Capital Expenditures, (v) dividends paid,
      and (vi) current maturities of long term Indebtedness."

      "Interest Expense" means, for any period of calculation, all interest on
      Indebtedness properly accrued as a liability during such period."

      3.7.     CAPITAL  EXPENDITURES.  Section  16.2 of the  Original  Loan 
Agreement is amended to read in its entirety as follows:

      "Borrower shall not make Capital Expenditures (including the Capital
      Expenditure Equivalent of Capital Leases entered into) that in the
      aggregate exceed $3,000,000 in any one fiscal year of Borrower. The
      "Capital Expenditure Equivalent" of a Capital Lease entered into in any
      fiscal year of Borrower shall be the amount which would have been the
      aggregate cost of the property leased if it had been purchased instead."

      3.8.     USE OF PROCEEDS. Section 14.1 of the Original Loan Agreement is
amended to read in its entirety as follows:

      "All proceeds of the Loans shall be used by Borrower solely for working
      capital and capital expenditures related to Borrower's business and for
      Borrower's general corporate purposes; provided, however, that no more
      than $5,000,000 of the total proceeds of the Loans may be used other than
      for working capital and general corporate purposes."

      3.9.     DEFINITIONS. The definition of Maturity Date in Exhibit 2.1 to
the Original Loan Agreement (Glossary and Index of Defined Terms) is amended to
read in its entirety as follows:

      "'Maturity Date: for each Revolving Loan and the Term Loan, the respective
      dates specified in Section 6.1 as the dates when they are payable in full
      with unpaid accrued interest."

4.    ADDITIONAL TERM LOAN ADVANCE. The Interest Period for the Term Loan shall
expire automatically on the Effective Date, and Borrower shall not be obligated
to make any payment to Lender under Section 4.10 of the Original Loan Agreement
as a consequence thereof. Lender will make a single additional Term Advance on
the Effective Date in the amount of the difference between the amount of the
Term Loan on the Effective Date and the amount of the Term Loan Commitment as
amended hereby. A Borrowing Officer shall designate whether the Term Loan upon
the making of the Term Advance is to be subject to LIBOR Accrual or Alternate
Base Rate Accrual and shall specify the Interest Period therefor if it is to be
subject to LIBOR Accrual.

                                       3


<PAGE>   4

5.    REPRESENTATIONS AND WARRANTIES OF BORROWER. Borrower hereby represents and
warrants to Bank as of the date hereof that (i) this Amendment has been duly
authorized by Borrower's Board of Directors, (ii) no consents are necessary from
any third parties for Borrower's execution, delivery or performance of this
Amendment, (iii) this Amendment constitutes the legal, valid and binding
obligation of Borrower enforceable against Borrower in accordance with its terms
except as the enforcement thereof may be limited by bankruptcy, insolvency or
other laws related to creditors rights generally or by the application of equity
principles, (iv) the representations and warranties in the Original Loan
Agreement are true and correct and have been true and correct at all times since
the Effective Date, and (v) there exists no Default or Event of Default under
the Original Loan Agreement, as amended by this Amendment. Borrower further
represents and warrants to Lender that (1) Borrower has (i) begun analyzing the
operations of Borrower and its subsidiaries and affiliates that could be
adversely affected by failure to become Year 2000 compliant (that is, that
computer applications, imbedded microchips and other systems will be able to
perform date-sensitive functions prior to and after December 31, 1999) and; (ii)
developed a plan for becoming Year 2000 compliant in a timely manner, the
implementation of which is on schedule in all material respects; (2) Borrower
reasonably believes that it will become Year 2000 compliant for its operations
and those of its subsidiaries and affiliates on a timely basis except to the
extent that a failure to do so could not reasonably be expected to have a
material adverse effect upon the financial condition of Borrower; and (3)
Borrower reasonably believes any suppliers and vendors that are material to the
operations of Borrower or its subsidiaries and affiliates will be Year 2000
compliant for their own computer applications except to the extent that a
failure to do so could not reasonably be expected to have a material adverse
effect upon the financial condition of Borrower.

6.    YEAR 2000 COVENANT. Borrower covenants and agrees to promptly notify Bank
in the event Borrower determines that any computer application which is material
to the operations of Borrower, its subsidiaries or any of its material vendors
or suppliers will not be fully Year 2000 compliant on a timely basis, except to
the extent that such failure could not reasonably be expected to have a material
adverse effect upon the financial condition of Borrower.

7.    EFFECT OF AMENDMENT. The execution, delivery and effectiveness of this
Amendment shall not operate as a waiver of any right, power or remedy of Bank
under the Original Loan Agreement or any of the other Loan Documents, nor
constitute a waiver of any provision of the Original Loan Agreement, any of the
other Loan Documents or any existing Default or Event of Default, nor act as a
release or subordination of the security interests of Bank under the Security
Documents. Each reference in the Original Loan Agreement to "the Agreement",
"hereunder", "hereof", "herein", or words of like import, shall be read as
referring to the Original Loan Agreement as amended by this Amendment.

8.    REAFFIRMATION. Borrower hereby acknowledges and confirms that (i) except
as expressly amended hereby, the Original Loan Agreement remains in full force
and effect, (ii) the Original Loan Agreement, as amended hereby, is in full
force and effect, (iii) Borrower has no defenses to its obligations under the
Original Loan Agreement as amended hereby and the other Loan Documents, and (iv)
Borrower has no claim against Bank arising from or in connection with the
Original Loan Agreement or the other Loan Documents.

9.    GOVERNING LAW. This Amendment has been executed and delivered in St. 
Louis, Missouri, and shall be governed by and construed under the laws of the
State of Missouri without giving effect to choice or conflicts of law principles
thereunder.


                                       4

<PAGE>   5
9.    SECTION  TITLES.  The section  titles in this  Amendment are for
convenience of reference only and shall not be construed so as to modify any
provisions of this Amendment.

10.   COUNTERPARTS; FACSIMILE TRANSMISSIONS. This Amendment may be executed in
one or more counterparts and on separate counterparts, each of which shall be
deemed an original, but all of which together shall constitute one and the same
instrument. Signatures to this Amendment may be given by facsimile or other
electronic transmission, and such signatures shall be fully binding on the party
sending the same.

11.   INCORPORATION BY REFERENCE. Bank and Borrower hereby agree that all of the
terms of the Loan Documents are incorporated in and made a part of this
Amendment by this reference.

12.   STATUTORY NOTICE. The following notice is given pursuant to Section 
432.045 of the Missouri Revised Statutes; nothing contained in such notice will
be deemed to limit or modify the terms of the Loan Documents or this Amendment:

      ORAL AGREEMENTS OR COMMITMENTS TO LOAN MONEY, EXTEND CREDIT OR TO FORBEAR
      FROM ENFORCING REPAYMENT OF A DEBT INCLUDING PROMISES TO EXTEND OR RENEW
      SUCH DEBT ARE NOT ENFORCEABLE. TO PROTECT YOU (BORROWER) AND US (CREDITOR)
      FROM MISUNDERSTANDING OR DISAPPOINTMENT, ANY AGREEMENTS WE REACH COVERING
      SUCH MATTERS ARE CONTAINED IN THIS WRITING, WHICH IS THE COMPLETE AND
      EXCLUSIVE STATEMENT OF THE AGREEMENT BETWEEN US, EXCEPT AS WE MAY LATER
      AGREE IN WRITING TO MODIFY IT.

BORROWER AND BANK HEREBY AFFIRM THAT THERE IS NO UNWRITTEN ORAL CREDIT AGREEMENT
BETWEEN BORROWER AND BANK WITH RESPECT TO THE SUBJECT MATTER OF THIS AMENDMENT.

                            [SIGNATURE PAGE FOLLOWS]


                                       5
<PAGE>   6


IN WITNESS WHEREOF, the parties have caused this Agreement to be executed by
appropriate duly authorized officers as of the Effective Date hereof.



LABARGE/STC, INC.                            LABARGE WIRELESS, INC.
by its VP-Secretary                          by its  VP-Secretary

/s/ William J. Maender                       /s/ William J. Maender
--------------------------                   --------------------------


Notice Address:                              Notice Address:
C/O LaBarge, Inc.                            C/O LaBarge, Inc.
9900A Clayton Road                           9900A Clayton Road
St. Louis, MO  63124                         St. Louis, MO  63124
Attn:    William J. Maender                  Attn:    William J. Maender
FAX # 812-9438                               FAX # 812-9438
TEL # 997-0800                               TEL # 997-0800

LABARGE, INC.                                NATIONSBANK, N.A.
by its VP-Finance & Secretary                by its Vice President


/s/ William J. Maender                       /s/ Jeffrey S. Potts
--------------------------                   --------------------------
                                                  Jeffrey S. Potts

Notice Address:                              Notice Address:
LaBarge, Inc.                                800 Market Street
9900A Clayton Road                           Mail Code MO1800-12-01
St. Louis, MO  63124                         St. Louis, MO  63101
Attn:    William J. Maender                  Attn:    Jeffrey S. Potts
FAX # 812-9438
TEL # 997-0800                               FAX # 466-6744
                                             TEL # 466-6061




                                       6

<PAGE>   7


                                    EXHIBIT A

                   FORM OF AMENDED AND RESTATED REVOLVING NOTE


                       AMENDED AND RESTATED REVOLVING NOTE

$15,000,000.00                                               St. Louis, Missouri
                                                              September 25, 1998

      For value received, LABARGE, INC., a Delaware corporation ("LaBarge"),
LABARGE/STC, INC., a Texas corporation ("LSTC"), and LABARGE WIRELESS, INC., a
Missouri corporation ("LWI") (LaBarge, LSTC, and LWI are referred to both
individually and collectively herein as "Borrower"), promise, jointly and
severally, to pay to the order of NATIONSBANK, N.A. (successor by merger to The
Boatmen's National Bank Of St. Louis) ("Lender") the principal sum of FIFTEEN
MILLION DOLLARS ($15,000,000.00) or such lesser aggregate unpaid principal
amount as shall be outstanding under this Revolving Note (this "Note"), plus all
interest accrued thereon, on the Maturity Date.

      Borrower further promises to pay interest from the date hereof on the
balance of said principal from time to time outstanding at a per annum rate or
rates determined pursuant to the Loan Agreement (defined below). Upon the
occurrence of any Event of Default as defined in the Loan Agreement, or at the
option of Lender upon the occurrence of a Default as defined in the Loan
Agreement, all outstanding principal and, to the extent permitted by law,
accrued interest in respect of this Note and all other amounts owing hereunder
shall bear interest, payable on demand, at the Default Rate set forth in the
Loan Agreement. In addition, such default rate of interest shall apply after
Maturity, whether by acceleration or otherwise. All such interest shall be
computed on the basis of a year deemed to consist of 360 days and paid for the
actual number of days elapsed. Interest shall be payable on such dates as are
provided under the Loan Agreement.

      Both principal and interest are payable in Dollars to Lender at its office
at 800 Market Street, St. Louis, Missouri 63101 (Attention: Jeffrey S. Potts).

      This Note is the Revolving Note referred to in, and is issued under the
terms of, and pursuant to the provisions of, that certain Loan Agreement dated
as of even date herewith, between Lender and Borrower (as it may be amended,
restated, extended, renewed, replaced, or otherwise modified from time to time,
the "Loan Agreement"). All capitalized terms used and not otherwise defined
herein shall have the same meanings as given them in the Loan Agreement.

      This Note is secured by the Collateral described in the Loan Documents,
executed from time to time by Borrower in favor of Lender as set forth in the
Loan Agreement and reference to the Loan Documents and the Loan Agreement is
made for a statement of the rights of the Lender with respect to such
Collateral.

      Borrower shall prepay the principal amount of this Note to the extent
provided in the Loan Agreement. Borrower may prepay the principal amount of this
Note to the extent and upon the conditions provided in the Loan Agreement.

      The date and amount of all disbursements and receipts representing
principal and receipts of interest by Lender with respect to the Revolving Loan
shall be recorded by Lender in the records it maintains with respect thereto.
The failure to record, or any error in recording, any of the foregoing shall


                                       i

<PAGE>   8

not, however, affect the obligations of Borrower under this Note to repay the
principal amount advanced hereunder together with all interest accruing thereon.
Such record as maintained by Lender shall constitute prima facie evidence of the
amount outstanding under this Note.

      Reference is made to the Loan Agreement for provisions regarding the
acceleration of the maturity hereof on the occurrence of any Event of Default,
which provisions are incorporated herein by this reference.

      If Borrower sells, assigns, transfers or conveys all or any part of the
Real Property Collateral or any interest therein without the prior written
consent of Lender as required by the Loan Agreement, all outstanding principal
and accrued interest under this Note shall become immediately due and payable.

      If any payment required under this Note or the Loan Agreement is not made
when due, or upon any other Event of Default, Borrower shall pay all costs of
collection on this Note, including but not limited to court costs and reasonable
attorneys fees and actual expenses of such attorneys, whether or not litigation
is commenced, including representation of Lender in connection with any
bankruptcy or insolvency proceeding of Borrower.

      Demand for payment, protest, notice of dishonor, and all other notices and
demands under this Note and any and all lack of diligence in the enforcement of
this Note are hereby waived by all who are or shall become parties to this Note
and the same hereby assent to each and every extension or postponement of the
time of payment, at or after demand, or other indulgence, and hereby waive any
and all notice thereof. Every such party by becoming a party to this Note
further waives any and all defenses which such party may have based on
suretyship or impairment of collateral with respect to this Note.

      No amendment, modification or waiver of any provision of this Note, nor
consent to any departure by Borrower herefrom, shall be effective unless the
same shall be in writing signed by an authorized officer of Lender, and then
only in the specific instance and for the purpose for which given. No failure on
the part of Lender to exercise, and no delay in exercising, any right under this
Note shall operate as a waiver thereof, nor shall any single or partial exercise
by Lender of any right under this Note preclude any other or further exercise
thereof, or the exercise of any other right. Each and every right granted to
Lender under this Note or allowed to it at law or in equity shall be deemed
cumulative and such remedies may be exercised from time to time concurrently or
consecutively at Lender's option.

      All notices required to be given or which may be given in connection with
this Note shall be given in the manner required for notices under the Loan
Agreement.

      This Note is governed by and shall be interpreted in accordance with the
laws of the State of Missouri, without regard to choice or conflict of laws
rules.

      This Note is an amendment and restatement of the revolving note from
Borrower to The Boatmen's National Bank of St. Louis dated as of June 25, 1996.

                            [SIGNATURE PAGE FOLLOWS]


                                       ii
<PAGE>   9



LABARGE/STC, INC.                         LABARGE WIRELESS, INC.
by its ____________________________       by its ____________________________


___________________________________       ___________________________________


Notice Address:                           Notice Address:
C/O LaBarge, Inc.                         C/O LaBarge, Inc.
9900A Clayton Road                        9900A Clayton Road
St. Louis, MO  63124                      St. Louis, MO  63124
Attn:    William J. Maender               Attn:    William J. Maender
FAX # 812-9438                            FAX # 812-9438
TEL # 997-0800                            TEL # 997-0800

                                          LABARGE WIRELESS, INC.              
                                          by its ____________________________ 
                                                                              
                                                                              
                                          ___________________________________ 


                                          Notice Address:
                                          LaBarge, Inc.
                                          9900A Clayton Road
                                          St. Louis, MO  63124
                                          Attn:    William J. Maender
                                          FAX # 812-9438
                                          TEL # 997-0800



                                      iii

<PAGE>   10


                                    EXHIBIT B

                     FORM OF AMENDED AND RESTATED TERM NOTE


                         AMENDED AND RESTATED TERM NOTE

$11,000,000.00                                               St. Louis, Missouri
                                                              September 25, 1998

      For value received, LABARGE, INC., a Delaware corporation ("LaBarge"),
LABARGE/STC, INC., a Texas Corporation ("LSTC"), and LABARGE WIRELESS, INC., a
Missouri corporation ("LWI") (LaBarge, LSTC, and LWI are referred to both
individually and collectively herein as "Borrower") promise, jointly and
severally, to pay to the order of NATIONSBANK, N.A. (successor by merger to The
Boatmen's National Bank Of St. Louis) ("Lender") the principal sum of ELEVEN
MILLION DOLLARS ($11,000,000.00) in accordance with the amortization schedule
contained in the Loan Agreement (defined below), plus all interest accrued
thereon, on the Maturity Date.

      Borrower further promises to pay interest from the date hereof on the
balance of said principal from time to time outstanding at a per annum rate or
rates determined pursuant to the Loan Agreement. Upon the occurrence of any
Event of Default as defined in the Loan Agreement, or at the option of Lender
upon the occurrence of a Default as defined in the Loan Agreement, all
outstanding principal and, to the extent permitted by law, accrued interest in
respect of this Term Note (this "Note"), and all other amounts owing hereunder
shall bear interest, payable on demand, at the Default Rate set forth in the
Loan Agreement. In addition, such default rate of interest shall apply after
Maturity, whether by acceleration or otherwise. All such interest shall be
computed on the basis of a year deemed to consist of 360 days and paid for the
actual number of days elapsed. Interest shall be payable on such dates as are
provided under the Loan Agreement.

      Both principal and interest are payable in Dollars to Lender at its office
at 800 Market Street, St. Louis, Missouri 63101 (Attention: Jeffrey S. Potts).

      This Note is the Term Note referred to in, and is issued under the terms
of, and pursuant to the provisions of, that certain Loan Agreement dated as of
even date herewith between Lender and Borrower (as it may be amended, restated,
extended, renewed, replaced, or otherwise modified from time to time, the "Loan
Agreement"). All capitalized terms used and not otherwise defined herein shall
have the same meanings as given them in the Loan Agreement.

      This Note is secured by the Collateral described in the Loan Documents,
executed from time to time by Borrower in favor of Lender as set forth in the
Loan Agreement and reference to the Loan Documents and the Loan Agreement is
made for a statement of the rights of the Lender with respect to such
Collateral.

      Borrower shall prepay the principal amount of this Note to the extent
provided in the Loan Agreement. Borrower may prepay the principal amount of this
Note to the extent and upon the conditions provided in the Loan Agreement.

      The date and amount of all disbursements and receipts representing
principal and receipts of interest by Lender with respect to the Term Loan shall
be recorded by Lender in the records it maintains with respect thereto. The
failure to record, or any error in recording, any of the foregoing shall not,

                                       i

<PAGE>   11


however, affect the obligations of Borrower under this Note to repay the
principal amount advanced hereunder together with all interest accruing thereon.
Such record as maintained by Lender shall constitute prima facie evidence of the
amount outstanding under this Note.

      Reference is made to the Loan Agreement for provisions regarding the
acceleration of the maturity hereof on the occurrence of any Event of Default,
which provisions are incorporated herein by this reference.

      If Borrower sells, assigns, transfers or conveys all or any part of the
Real Property Collateral or any interest therein without the prior written
consent of Lender as required by the Loan Agreement, all outstanding principal
and accrued interest under this Note shall become immediately due and payable.

      If any payment required under this Note or the Loan Agreement is not made
when due, or upon any other Event of Default, Borrower shall pay all costs of
collection on this Note, including but not limited to court costs and reasonable
attorneys fees and actual expenses of such attorneys, whether or not litigation
is commenced, including representation of Lender in connection with any
bankruptcy or insolvency proceeding of Borrower.

      Demand for payment, protest, notice of dishonor, and all other notices and
demands under this Note and any and all lack of diligence in the enforcement of
this Note are hereby waived by all who are or shall become parties to this Note
and the same hereby assent to each and every extension or postponement of the
time of payment, at or after demand, or other indulgence, and hereby waive any
and all notice thereof. Every such party by becoming a party to this Note
further waives any and all defenses which such party may have based on
suretyship or impairment of collateral with respect to this Note.

      No amendment, modification or waiver of any provision of this Note, nor
consent to any departure by Borrower herefrom, shall be effective unless the
same shall be in writing signed by an authorized officer of Lender, and then
only in the specific instance and for the purpose for which given. No failure on
the part of Lender to exercise, and no delay in exercising, any right under this
Note shall operate as a waiver thereof, nor shall any single or partial exercise
by Lender of any right under this Note preclude any other or further exercise
thereof, or the exercise of any other right. Each and every right granted to
Lender under this Note or allowed to it at law or in equity shall be deemed
cumulative and such remedies may be exercised from time to time concurrently or
consecutively at Lender's option.

      All notices required to be given or which may be given in connection with
this Note shall be given in the manner required for notices under the Loan
Agreement.

      This Note is governed by and shall be interpreted in accordance with the
laws of the State of Missouri, without regard to choice of conflict of laws
rules.

      This Note is an amendment and restatement of the Term Note from Borrower
to The Boatmen's National Bank of St. Louis dated as of June 25, 1996.

                            [SIGNATURE PAGE FOLLOWS]

                                       ii
<PAGE>   12


LABARGE/STC, INC.                         LABARGE WIRELESS, INC.
by its ____________________________       by its ____________________________


___________________________________       ___________________________________


Notice Address:                           Notice Address:
C/O LaBarge, Inc.                         C/O LaBarge, Inc.
9900A Clayton Road                        9900A Clayton Road
St. Louis, MO  63124                      St. Louis, MO  63124
Attn:    William J. Maender               Attn:    William J. Maender
FAX # 812-9438                            FAX # 812-9438
TEL # 997-0800                            TEL # 997-0800

                                          LABARGE WIRELESS, INC.              
                                          by its ____________________________ 
                                                                              
                                                                              
                                          ___________________________________ 


                                          Notice Address:
                                          LaBarge, Inc.
                                          9900A Clayton Road
                                          St. Louis, MO  63124
                                          Attn:    William J. Maender
                                          FAX # 812-9438
                                          TEL # 997-0800





                                      iii
<PAGE>   13


                                    EXHIBIT C

       ADDITIONS TO THE DISCLOSURE SCHEDULE OF THE ORIGINAL LOAN AGREEMENT

If none listed, there are none.








                                       i
<PAGE>   14
                 
                         AMENDED AND RESTATED TERM NOTE

$11,000,000.00                                               St. Louis, Missouri
                                                              September 25, 1998

      For value received, LABARGE, INC., a Delaware corporation ("LaBarge"),
LABARGE/STC, INC., a Texas Corporation ("LSTC"), and LABARGE WIRELESS, INC., a
Missouri corporation ("LWI") (LaBarge, LSTC, and LWI are referred to both
individually and collectively herein as "Borrower") promise, jointly and
severally, to pay to the order of NATIONSBANK, N.A. (successor by merger to The
Boatmen's National Bank Of St. Louis) ("Lender") the principal sum of ELEVEN
MILLION DOLLARS ($11,000,000.00) in accordance with the amortization schedule
contained in the Loan Agreement (defined below), plus all interest accrued
thereon, on the Maturity Date.

      Borrower further promises to pay interest from the date hereof on the
balance of said principal from time to time outstanding at a per annum rate or
rates determined pursuant to the Loan Agreement. Upon the occurrence of any
Event of Default as defined in the Loan Agreement, or at the option of Lender
upon the occurrence of a Default as defined in the Loan Agreement, all
outstanding principal and, to the extent permitted by law, accrued interest in
respect of this Term Note (this "Note"), and all other amounts owing hereunder
shall bear interest, payable on demand, at the Default Rate set forth in the
Loan Agreement. In addition, such default rate of interest shall apply after
Maturity, whether by acceleration or otherwise. All such interest shall be
computed on the basis of a year deemed to consist of 360 days and paid for the
actual number of days elapsed. Interest shall be payable on such dates as are
provided under the Loan Agreement.

      Both principal and interest are payable in Dollars to Lender at its office
at 800 Market Street, St. Louis, Missouri 63101 (Attention: Jeffrey S. Potts).

      This Note is the Term Note referred to in, and is issued under the terms
of, and pursuant to the provisions of, that certain Loan Agreement dated as of
even date herewith between Lender and Borrower (as it may be amended, restated,
extended, renewed, replaced, or otherwise modified from time to time, the "Loan
Agreement"). All capitalized terms used and not otherwise defined herein shall
have the same meanings as given them in the Loan Agreement.

      This Note is secured by the Collateral described in the Loan Documents,
executed from time to time by Borrower in favor of Lender as set forth in the
Loan Agreement and reference to the Loan Documents and the Loan Agreement is
made for a statement of the rights of the Lender with respect to such
Collateral.

      Borrower shall prepay the principal amount of this Note to the extent
provided in the Loan Agreement. Borrower may prepay the principal amount of this
Note to the extent and upon the conditions provided in the Loan Agreement.

      The date and amount of all disbursements and receipts representing
principal and receipts of interest by Lender with respect to the Term Loan shall
be recorded by Lender in the records it maintains with respect thereto. The
failure to record, or any error in recording, any of the foregoing shall not,
however, affect the obligations of Borrower under this Note to repay the
principal amount advanced hereunder together with all interest 




<PAGE>   15


accruing thereon. Such record as maintained by Lender shall constitute prima
facie evidence of the amount outstanding under this Note.

      Reference is made to the Loan Agreement for provisions regarding the
acceleration of the maturity hereof on the occurrence of any Event of Default,
which provisions are incorporated herein by this reference.

      If Borrower sells, assigns, transfers or conveys all or any part of the
Real Property Collateral or any interest therein without the prior written
consent of Lender as required by the Loan Agreement, all outstanding principal
and accrued interest under this Note shall become immediately due and payable.

      If any payment required under this Note or the Loan Agreement is not made
when due, or upon any other Event of Default, Borrower shall pay all costs of
collection on this Note, including but not limited to court costs and reasonable
attorneys fees and actual expenses of such attorneys, whether or not litigation
is commenced, including representation of Lender in connection with any
bankruptcy or insolvency proceeding of Borrower.

      Demand for payment, protest, notice of dishonor, and all other notices and
demands under this Note and any and all lack of diligence in the enforcement of
this Note are hereby waived by all who are or shall become parties to this Note
and the same hereby assent to each and every extension or postponement of the
time of payment, at or after demand, or other indulgence, and hereby waive any
and all notice thereof. Every such party by becoming a party to this Note
further waives any and all defenses which such party may have based on
suretyship or impairment of collateral with respect to this Note.

      No amendment, modification or waiver of any provision of this Note, nor
consent to any departure by Borrower herefrom, shall be effective unless the
same shall be in writing signed by an authorized officer of Lender, and then
only in the specific instance and for the purpose for which given. No failure on
the part of Lender to exercise, and no delay in exercising, any right under this
Note shall operate as a waiver thereof, nor shall any single or partial exercise
by Lender of any right under this Note preclude any other or further exercise
thereof, or the exercise of any other right. Each and every right granted to
Lender under this Note or allowed to it at law or in equity shall be deemed
cumulative and such remedies may be exercised from time to time concurrently or
consecutively at Lender's option.

      All notices required to be given or which may be given in connection with
this Note shall be given in the manner required for notices under the Loan
Agreement.

      This Note is governed by and shall be interpreted in accordance with the
laws of the State of Missouri, without regard to choice of conflict of laws
rules.

      This Note is an amendment and restatement of the Term Note from Borrower
to The Boatmen's National Bank of St. Louis dated as of June 25, 1996.

                            [SIGNATURE PAGE FOLLOWS]

                                       
                                       2


<PAGE>   16


LABARGE/STC, INC.                         LABARGE WIRELESS, INC.
by its VP-Secretary                       by its VP-Secretary

/s/ William J. Maender                    /s/ William J. Maender
-----------------------------------       -----------------------------------


Notice Address:                           Notice Address:
C/O LaBarge, Inc.                         C/O LaBarge, Inc.
9900A Clayton Road                        9900A Clayton Road
St. Louis, MO  63124                      St. Louis, MO  63124
Attn:    William J. Maender               Attn:    William J. Maender
FAX # 812-9438                            FAX # 812-9438
TEL # 997-0800                            TEL # 997-0800


                                          LABARGE WIRELESS, INC.              
                                          by its VP - Finance & Secretary

                                          /s/ William J. Maender
                                          ----------------------------------- 
                                          William J. Maender



                                          Notice Address:
                                          LaBarge, Inc.
                                          9900A Clayton Road
                                          St. Louis, MO  63124
                                          Attn:    William J. Maender
                                          FAX # 812-9438
                                          TEL # 997-0800





                                        3



<PAGE>   17


                       AMENDED AND RESTATED REVOLVING NOTE

$15,000,000.00                                               St. Louis, Missouri
                                                              September 25, 1998

      For value received, LABARGE, INC., a Delaware corporation ("LaBarge"),
LABARGE/STC, INC., a Texas corporation ("LSTC"), and LABARGE WIRELESS, INC., a
Missouri corporation ("LWI") (LaBarge, LSTC, and LWI are referred to both
individually and collectively herein as "Borrower"), promise, jointly and
severally, to pay to the order of NATIONSBANK, N.A. (successor by merger to The
Boatmen's National Bank Of St. Louis) ("Lender") the principal sum of FIFTEEN
MILLION DOLLARS ($15,000,000.00) or such lesser aggregate unpaid principal
amount as shall be outstanding under this Revolving Note (this "Note"), plus all
interest accrued thereon, on the Maturity Date.

      Borrower further promises to pay interest from the date hereof on the
balance of said principal from time to time outstanding at a per annum rate or
rates determined pursuant to the Loan Agreement (defined below). Upon the
occurrence of any Event of Default as defined in the Loan Agreement, or at the
option of Lender upon the occurrence of a Default as defined in the Loan
Agreement, all outstanding principal and, to the extent permitted by law,
accrued interest in respect of this Note and all other amounts owing hereunder
shall bear interest, payable on demand, at the Default Rate set forth in the
Loan Agreement. In addition, such default rate of interest shall apply after
Maturity, whether by acceleration or otherwise. All such interest shall be
computed on the basis of a year deemed to consist of 360 days and paid for the
actual number of days elapsed. Interest shall be payable on such dates as are
provided under the Loan Agreement.

      Both principal and interest are payable in Dollars to Lender at its office
at 800 Market Street, St. Louis, Missouri 63101 (Attention: Jeffrey S. Potts).

      This Note is the Revolving Note referred to in, and is issued under the
terms of, and pursuant to the provisions of, that certain Loan Agreement dated
as of even date herewith, between Lender and Borrower (as it may be amended,
restated, extended, renewed, replaced, or otherwise modified from time to time,
the "Loan Agreement"). All capitalized terms used and not otherwise defined
herein shall have the same meanings as given them in the Loan Agreement.

      This Note is secured by the Collateral described in the Loan Documents,
executed from time to time by Borrower in favor of Lender as set forth in the
Loan Agreement and reference to the Loan Documents and the Loan Agreement is
made for a statement of the rights of the Lender with respect to such
Collateral.

      Borrower shall prepay the principal amount of this Note to the extent
provided in the Loan Agreement. Borrower may prepay the principal amount of this
Note to the extent and upon the conditions provided in the Loan Agreement.

      The date and amount of all disbursements and receipts representing
principal and receipts of interest by Lender with respect to the Revolving Loan
shall be recorded by Lender in the records it maintains with respect thereto.
The failure to record, or any error in recording, any of the foregoing shall
not, however, affect the obligations of Borrower 



<PAGE>   18




under this Note to repay the principal amount advanced hereunder together with
all interest accruing thereon. Such record as maintained by Lender shall
constitute prima facie evidence of the amount outstanding under this Note.

      Reference is made to the Loan Agreement for provisions regarding the
acceleration of the maturity hereof on the occurrence of any Event of Default,
which provisions are incorporated herein by this reference.

      If Borrower sells, assigns, transfers or conveys all or any part of the
Real Property Collateral or any interest therein without the prior written
consent of Lender as required by the Loan Agreement, all outstanding principal
and accrued interest under this Note shall become immediately due and payable.

      If any payment required under this Note or the Loan Agreement is not made
when due, or upon any other Event of Default, Borrower shall pay all costs of
collection on this Note, including but not limited to court costs and reasonable
attorneys fees and actual expenses of such attorneys, whether or not litigation
is commenced, including representation of Lender in connection with any
bankruptcy or insolvency proceeding of Borrower.

      Demand for payment, protest, notice of dishonor, and all other notices and
demands under this Note and any and all lack of diligence in the enforcement of
this Note are hereby waived by all who are or shall become parties to this Note
and the same hereby assent to each and every extension or postponement of the
time of payment, at or after demand, or other indulgence, and hereby waive any
and all notice thereof. Every such party by becoming a party to this Note
further waives any and all defenses which such party may have based on
suretyship or impairment of collateral with respect to this Note.

      No amendment, modification or waiver of any provision of this Note, nor
consent to any departure by Borrower herefrom, shall be effective unless the
same shall be in writing signed by an authorized officer of Lender, and then
only in the specific instance and for the purpose for which given. No failure on
the part of Lender to exercise, and no delay in exercising, any right under this
Note shall operate as a waiver thereof, nor shall any single or partial exercise
by Lender of any right under this Note preclude any other or further exercise
thereof, or the exercise of any other right. Each and every right granted to
Lender under this Note or allowed to it at law or in equity shall be deemed
cumulative and such remedies may be exercised from time to time concurrently or
consecutively at Lender's option.

      All notices required to be given or which may be given in connection with
this Note shall be given in the manner required for notices under the Loan
Agreement.

      This Note is governed by and shall be interpreted in accordance with the
laws of the State of Missouri, without regard to choice or conflict of laws
rules.

      This Note is an amendment and restatement of the revolving note from
Borrower to The Boatmen's National Bank of St. Louis dated as of June 25, 1996.

                            [SIGNATURE PAGE FOLLOWS]


                                        2


<PAGE>   19



LABARGE/STC, INC.                         LABARGE WIRELESS, INC.
by its VP-Secretary                       by its VP-Secretary

/s/ William J. Maender                    /s/ William J. Maender
-----------------------------------       -----------------------------------


Notice Address:                           Notice Address:
C/O LaBarge, Inc.                         C/O LaBarge, Inc.
9900A Clayton Road                        9900A Clayton Road
St. Louis, MO  63124                      St. Louis, MO  63124
Attn:    William J. Maender               Attn:    William J. Maender
FAX # 812-9438                            FAX # 812-9438
TEL # 997-0800                            TEL # 997-0800



                                          LABARGE WIRELESS, INC.              
                                          by its VP-Finance & Secretary

                                          /s/ William J. Maender
                                          ----------------------------------- 
                                          William J. Maender



                                          Notice Address:
                                          LaBarge, Inc.
                                          9900A Clayton Road
                                          St. Louis, MO  63124
                                          Attn:    William J. Maender
                                          FAX # 812-9438
                                          TEL # 997-0800



                                        3