<PAGE>

                                                                   Exhibit 4.6.3

                           AMENDMENT AND RESTATEMENT
                                    OF THE
                             REVOLVING CREDIT NOTE

                           Dated as of July 8, 1993



$16,750,000                                                   September 30, 2000

     FOR VALUE RECEIVED, the undersigned AEROVOX INCORPORATED, a Delaware
corporation with its chief executive office at 740 Belleville Avenue, New
Bedford, Massachusetts 02745 (the "Borrower"), hereby absolutely and
unconditionally promises to pay to the order of FLEET NATIONAL BANK, as
successor to BANKBOSTON, N.A., a national banking association with its principal
place of business at 100 Federal Street, Boston, Massachusetts 02110 (the
"Bank"):

     (a)  on the Maturity Date, the Principal Amount of this note or if less,
          the aggregate unpaid principal amount of Loans advanced by the Bank to
          the Borrower pursuant to the Second Amended and Restated Revolving
          Credit Agreement dated as of June 30, 1999, as amended March 17, 2000
          and September 30, 2000 by and between the Borrower and the Bank, as
          amended or supplemented from time to time (the "Credit Agreement");
          and

     (b)  interest on the principal balance hereof from time to time outstanding
          from the date hereof until paid in full, at the times and at the
          applicable interest rate provided in the Credit Agreement.

     For purposes of this Note, the "Principal Amount" shall mean the maximum
principal amount of Loans which the Bank may advance pursuant to the Credit
Agreement during the time periods set forth below.

               Time Period                      Principal Amount
               -----------                      ----------------

               October 1-31, 2000               $16,000,000.00
               November 1-30, 2000              $16,000,000.00
               December 1-15, 2000              $16,750,000.00
               December 16-31, 2000             $16,750,000.00
               January 1-31, 2001               $16,750,000.00
               February 1-28, 2001              $16,000,000.00
               March 1-31, 2001                 $15,500,000.00
               April 1, 2001-Maturity Date      $14,500,000.00

     This Note constitutes an amendment and restatement in its entirety of the
promissory note of the Borrower to the Bank dated as of July 8, 1993 as
previously amended and restated June 30, 1999.
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                                                                   Exhibit 4.6.3



     This Note evidences borrowings under, is subject to the terms and
conditions of, has been issued by the Borrower in accordance with the terms of
the Credit Agreement and is the Note referred to therein.  The Bank and any
holder hereof is entitled to the benefits and subject to the conditions of the
Credit Agreement and may enforce the agreements of the agreements of the
Borrower contained therein, and any holder hereof may exercise the respective
remedies provided for thereby or otherwise available in respect thereof, all in
accordance with the respective terms thereof.  This Note is secured by the
Security Documents described in the Credit Agreement.  Capitalized terms used in
this Note and not otherwise defined herein shall have the same meanings as in
the Credit Agreement.

     The Bank is hereby irrevocably authorized by the Borrower to endorse on the
schedule attached to this Note or a confirmation of such schedule attached
hereto and mad a part hereof, an appropriate notation evidencing advances and
repayments of principal of this Note, provided that failure by the Bank to make
                                      --------
any such notations shall not affect any of the Borrower's obligations or the
validity of any repayments made by the Borrower in respect to this Note.

     The Borrower has the right in certain circumstance and the obligation under
certain other circumstances to repay or prepay the whole or part of the
principal this Note on the terms and conditions specified in the Credit
Agreement.

     If any one or more of the Events of Default shall occur, the entire unpaid
principal amount of this Note an all of the unpaid interest accrued thereon may
become or be declared due and payable in the manner and with the effect provided
in the Credit Agreement.

     The Borrower and every endorser and guarantor of this Note or the
obligations represented hereby waive presentment, demand, notice, protest and
all other demands and notices in connection with the delivery, acceptance,
performance, default or enforcement of this Note, assent to any extension or
postponement of the time of payment or any other indulgence, to any
substitution, exchange or release of collateral and to the addition or release
of any other party or person primarily or secondarily liable.

     This Note shall be deemed to take effect as a sealed instrument under the
laws of the Commonwealth of Massachusetts and for all purposes shall be
construed in accordance with such laws.

     IN WITNESS WHEREOF, the Borrower has caused this Note to be signed by its
duly authorized officer as of September 30, 2000.

     (Corporate Seal)                               AEROVOX INCORPORATED

                                                    F. Randal Hunt