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                                                                 Exhibit 10.4(i)


                     PROMISSORY NOTE MODIFICATION AGREEMENT

This Agreement is made and entered into on March 16, 1998 ("Agreement Date"), to
be effective as of March 16, 1998 ("Effective Date"), by and between BOWMAR
INSTRUMENT CORPORATION, an Indiana corporation (if more than one, jointly and
severally, "Maker") and Bank One, Arizona, NA ("Bank One"),

                                   WITNESSETH:

WHEREAS, Maker heretofore executed a promissory note in the amount of
$4,000,000.00 dated, August 28, 1995 in favor of Bank One as same may have been
amended or modified from time to time ("Promissory Note"); and, WHEREAS, Maker
hereby acknowledges, agrees, verifies, ratifies and affirms that as of Agreement
Date, the outstanding principal balance on the Promissory Note is ONE MILLION
FIVE HUNDRED FOUR THOUSAND NINE HUNDRED THREE AND 55/100 DOLLARS ($1,504,903.55)
plus accrued interest and charges; and, WHEREAS, the Promissory Note has at all
times been, and is now, continuously and without interruption outstanding in
favor of Bank One; and WHEREAS, Maker has requested that the Promissory Note be
modified to the limited extent as hereinafter set forth; and, WHEREAS, Bank One
has agreed to such modification; NOW THEREFORE, by mutual agreement of the
parties and in mutual consideration of the agreements contained herein and for
other good and valuable considerations, the receipt and sufficiency of which is
hereby acknowledged, the parties hereto agree that the Promissory Note is
modified as hereinafter indicated.

1.       ACCURACY OF RECITALS.

Maker acknowledges the accuracy of the Recitals, stated above.

2.       MODIFICATION OF PROMISSORY NOTE.

         2.1 The maturity date of the Promissory Note is changed from February 
28, 1999 to February 28, 2000.

         2.2 Each of the Loan Documents is modified to provide that it shall be
a default or an event of default thereunder if Maker shall fail to comply with
any of the covenants of Maker herein or if any representation or warranty by
Maker or by any guarantor herein is materially incomplete, incorrect, or
misleading as of the date hereof. As used in this Agreement, "Loan Documents"
shall include the Promissory Note and all documents executed by Maker(s) or
others in connection with the Loan which is represented by the Promissory Note.

         2.3 Each reference in the Loan Documents to any of the Loan Documents
shall be a reference to such document as modified herein.

3.       RATIFICATION OF LOAN DOCUMENT AND COLLATERAL.

The Loan Documents are ratified and affirmed by Maker and shall remain in full
force and effect as modified herein. Any property or rights to or interest in
property granted as security in the Loan Documents shall remain as security for
the loan and the obligations of Maker in the Loan Documents.

4.       BORROWER REPRESENTATIONS AND WARRANTIES.

Maker represents and warrants to Bank One:

         4.1 No default or event of default under any of the Loan Documents as
modified hereby, nor any event, that, with the giving of notice or the passage
of time or both, would be a default or an event of default under the Loan
Documents as modified herein has occurred and is continuing.

         4.2 There has been no material adverse change in the financial
conditions of Maker or any other person whose financial statement has been
delivered to Bank in connection with the Promissory Note from the most recent
financial statement received by Bank.

         4.3 Each and all representations and warranties of Maker in the Loan
Documents are accurate on the date hereof.

         4.4 Maker has no claims, counterclaims, defenses, or set-offs with
respect to the Loan or the Loan Documents as modified herein.

         4.5 The Promissory Note and Loan Documents as modified herein are the
legal, valid, and binding obligation of Borrower, enforceable against Maker in
accordance with their terms.


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4.6 Maker is validly existing under the laws of the State of its formation or
organization and has the requisite power and authority to execute and deliver
this Agreement and to perform the Loan Documents as modified herein. The
execution and delivery of this Agreement and the performance of the Loan
Documents as modified herein have been duly authorized by all requisite action
by or on behalf of Maker. This Agreement has been duly executed and delivered on
behalf of Maker.

5.       BORROWER COVENANTS.

Maker covenants with Bank One.

         5.1 Maker shall execute, deliver, and provide to Bank One such
additional agreements, DOCUMENTS, AND instruments as reasonably required by Bank
One to effectuate the intent of this Agreement.

         5.2 Maker fully, finally, and forever releases and discharges Bank One
and its successors, assigns, directors, officers, employees, agents, and
representatives from any and all actions, cause of action, claims, debts,
demands, liabilities, obligations, and suits, of whatever kind or nature, in law
or equity of Maker, whether now known or unknown to Maker, (i) in respect of the
Loan, the Loan documents, or the actions or omissions of Bank One in respect of
the Loan or the Loan Documents and (ii) arising from events occurring prior to
the date of this Agreement. As used in this Agreement, "Loan Documents" shall
include the Promissory Note and all documents executed by Maker(s) in connection
with the Loan which is represented by the Promissory Note.

         5.3 Contemporaneously with the execution and delivery of this
Agreement, Maker has paid to Bank:

                  5.3.1 All accrued and unpaid interest under the Promissory
Note and all amounts, other THAN interest and principal, due and payable by
Maker under the Loan Documents as the date hereof.

                  5.3.2 All the internal and external costs and expenses
incurred by Bank One in connection with thus Agreement (including, without
limitation, inside and outside attorneys, appraisal, appraisal review,
processing, title, filing, and recording costs, expenses, and fees).

6.       EXECUTION AND DELIVERY OF AGREEMENT BY BANK.

Bank One shall not be bound by this Agreement until (i) Bank One has executed
and delivered this Agreement, (ii) Maker has performed all of the obligations of
Maker under this Agreement to be performed contemporaneously with the execution
and delivery of this Agreement, (iii) each guarantor(s) of the Loan, if any, has
executed this Agreement and (iv) if required by Bank One, Maker and any
guarantor(s) have executed and delivered to Bank One an arbitration resolution,
and an environmental questionnaire, and an environmental certification and
indemnity agreement.

7.       INTEGRATION, ENTIRE AGREEMENT, CHANGE, DISCHARGE, TERMINATION, OR 
         WAIVER.

The Loan Documents as modified herein contain the complete understanding and
agreement of Maker and Bank One in respect of the Loan and supersede all prior
representations, warranties, agreements, arrangements, understandings, and
negotiations. No provision of the Loan Documents as modified herein may be
changed, discharged, supplemented, terminated, or waived except in a writing
signed by the parties thereto.

8.       BINDING EFFECT.

The Loan Documents as modified herein shall be binding upon and shall inure to
the benefit of Maker and Bank One and their successors and assigns and the
executors, legal administrators, personal representatives, heirs, devisees, and
beneficiaries of Maker, provided, however, Maker may not assign any of its right
or delegate any of its obligation under the Loan Documents and any purported
assignment or delegation shall be void.

9.       CHOICE OF LAW

This Agreement shall be governed by and construed in accordance with the laws of
the State of Arizona without giving effect to conflicts of law principles.

10.      COUNTERPART EXECUTION.

This Agreement may be executed in one or more counterparts, each of which shall
be deemed an original and all of which together shall constitute one and the
same document. Signature pages may be detached from the counterparts and
attached to a single copy of this Agreement to physically from one document.


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11.      NOT A NOVATION.

This Agreement is a modification only and not a novation. Except for the
above-quoted modification(s), the Promissory Note, any agreement or security
document, and all the terms and conditions thereof, shall be and remain in full
force and effect with the changes herein deemed to be incorporated therein. This
Agreement is to be considered attached to the Promissory Note and made a part
thereof. This Agreement shall not release or affect the liability of any
guarantor, surety or endorser of the Promissory Note or release any owner of
collateral securing the Promissory Note. The validity, priority and
enforceability of the Promissory Note shall not be impaired hereby.

                                               BOWMAR INSTRUMENT CORPORATION,
                                               an Indiana corporation



                                               By: /s/ Joseph G. Warren, Jr.
                                                  ---------------------------
                                               Name:   Joseph G. Warren, Jr.
                                               Its:    Vice President



BANK ONE'S ACCEPTANCE

The foregoing Promissory Note Modification Agreement is hereby agreed to and
acknowledged this 16th day of March, 1998.

                                               BANK ON ARIZONA, NA

                                               By: /s/ Chad Christian
                                                  ---------------------------
                                               Name: Chad Christian
                                               Its: Vice President





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