EXHIBIT 4.16


                   AMENDED AND RESTATED REVOLVING CREDIT NOTE
                   ------------------------------------------

                                                                  March 18, 2004
$4,500,000                                                      Philadelphia, PA

         FOR VALUE RECEIVED, the undersigned, Selas Corporation of America, a
Pennsylvania business corporation with its chief executive office and principal
place of business at c/o RTI, 1260 Red Fox Road, Arden Hills, MN 55112 (the
"Borrower"), promises to pay to the order of Wachovia Bank, National Association
(formerly known as First Union National Bank) with offices located at Broad and
Walnut Streets, Philadelphia, PA 19109 (the "Lender") the principal sum of Four
Million Five Hundred Thousand Dollars ($4,500,000) or, if less, the aggregate
outstanding principal balance of all advances made by the Lender to the Borrower
under the Amended, Restated and Consolidated Loan Agreement dated of even date
by and among the Borrower, Resistance Technology, Inc., a Minnesota business
corporation with offices located at 1260 Red Fox Road, Arden Hills, MN 55112,
RTI Electronics, Inc., a Delaware corporation with offices located at 1800 Via
Burton Street, Anaheim, CA 92806 and Lender (as amended, restated, modified or
supplemented from time to time, the "Agreement"), pursuant to the "Revolving
Loan" as defined in the Agreement, together with interest, from the date of the
Agreement, in like money, at said office of the Lender, at the time and at rates
per annum as provided in the Agreement.

         This note (the "Note") amends and completely restates and evidences the
indebtedness outstanding under and is substituted for, but not in payment,
satisfaction, cancellation or novation of, the Amended and Restated Revolving
Credit Note dated January 19, 2001 which was issued by the Borrower to the
Lender. As of the date hereof, this Note shall be deemed to be the Revolving
Credit Facility Note referred to in the Agreement and shall evidence the
indebtedness incurred under, and be entitled to the benefits of, the Agreement.
All terms used and not otherwise defined in this Note shall have the meanings
given to them in the Agreement. Upon the occurrence of any Event of Default set
forth in the Agreement, the entire unpaid balance of principal and accrued
interest of this Note and all other amounts due under the Agreement shall, at
the option of the Lender, be immediately due and payable without presentment,
demand, protest or notice of any kind, all of which are expressly waived.

         Until maturity (whether by acceleration or otherwise), the outstanding
principal balance hereunder shall bear interest at the rates and shall be
payable at the times and in the manner set forth in the Agreement. Subsequent to
maturity, including after judgment, or upon the occurrence of any Event of
Default set forth in the Agreement, interest on the outstanding principal
balance hereunder shall accrue at an annual rate equal to the Base Rate plus
five percent (5%) and shall be payable on demand.

         Time is of the essence of this Note. All payments of principal and
interest shall be made in full in lawful money of the United States of America,
without set-off, counterclaim, deduction or withholding for any reason
whatsoever, at the offices of the Lender, or at such other place as may be
directed by the Lender.




         In the event any interest rate applicable hereto is in excess of the
highest rate allowable under applicable law, then the rate of such interest will
be reduced to the highest rate not in excess of such maximum allowable interest
and any excess previously paid by Borrower shall be deemed to have been applied
against principal.

         If Borrower subscribes to the Lender's cash management services and
such services are applicable to the Revolving Loan, the terms of such services
shall control the manner in which funds are transferred between the applicable
demand deposit account and the Revolving Loan for credit or debit to the line of
credit.

         UPON THE OCCURRENCE OF AN EVENT OF DEFAULT, THE BORROWER IRREVOCABLY
AUTHORIZES THE PROTHONOTARY OR ANY ATTORNEY OF ANY COURT OF RECORD IN
PENNSYLVANIA OR ELSEWHERE TO APPEAR FOR AND CONFESS JUDGMENT AGAINST THE
BORROWER FOR ANY AND ALL AMOUNTS UNPAID ON THIS NOTE AND UNDER THE AGREEMENT,
INCLUDING INTEREST THEREON TO DATE OF PAYMENT (SUCH AMOUNT AND THE OCCURRENCE OF
SUCH EVENT OF DEFAULT TO BE AS EVIDENCED BY A COMPLAINT OR AN AFFIDAVIT SIGNED
BY AN OFFICER OF THE LENDER) TOGETHER WITH FEES OF COUNSEL, DISBURSEMENTS AND
COSTS OF SUIT, AS SET FORTH BELOW, RELEASING ALL ERRORS AND WAIVING RIGHTS OF
APPEAL. IF A COPY OF THIS NOTE, VERIFIED BY AFFIDAVIT, SHALL HAVE BEEN FILED IN
SUCH PROCEEDING, IT SHALL NOT BE NECESSARY TO FILE THE ORIGINAL AS A WARRANT OF
ATTORNEY. THE BORROWER WAIVES THE RIGHT TO ANY STAY OF EXECUTION AND THE BENEFIT
OF ALL EXEMPTION LAWS NOW OR HEREAFTER IN EFFECT. NO SINGLE EXERCISE OF THIS
WARRANT AND POWER TO CONFESS JUDGMENT SHALL BE DEEMED TO EXHAUST THIS POWER,
WHETHER OR NOT ANY SUCH EXERCISE SHALL BE HELD BY ANY COURT TO BE INVALID,
VOIDABLE OR VOID, BUT THIS POWER SHALL CONTINUE UNDIMINISHED AND MAY BE
EXERCISED FROM TIME TO TIME AS OFTEN AS THE LENDER SHALL ELECT UNTIL THIS NOTE
AND ALL SUMS DUE UNDER THIS NOTE AND THE AGREEMENT SHALL HAVE BEEN PAID IN FULL.

         If the Lender should engage legal counsel in the course of collection
of this Note upon the occurrence of an Event of Default, the Borrower shall pay
to the Lender all fees and disbursements reasonably incurred by such counsel and
all costs of suit.

         THE BORROWER AND THE LENDER CONSENT TO THE JURISDICTION OF ANY STATE OR
FEDERAL COURT LOCATED WITHIN THE EASTERN DISTRICT OF PENNSYLVANIA IN ANY AND ALL
ACTIONS AND PROCEEDINGS ARISING UNDER OR PURSUANT TO THIS NOTE OR ARISING UNDER
OR PURSUANT TO ANY AGREEMENT, DOCUMENT OR INSTRUMENT EXECUTED IN CONNECTION WITH
OR RELATING TO THIS NOTE. THE BORROWER IRREVOCABLY AGREES TO SERVICE OF PROCESS
BY CERTIFIED MAIL, RETURN RECEIPT REQUESTED, TO SUCH ADDRESS AS THE BORROWER MAY
DIRECT BY WRITTEN NOTICE TO THE LENDER.




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         THE BORROWER IRREVOCABLY WAIVES A JURY TRIAL AND ANY RIGHT TO A JURY
TRIAL IN ANY ACTIONS OR PROCEEDINGS ARISING UNDER OR PURSUANT TO THIS NOTE OR
ARISING UNDER OR PURSUANT TO ANY AGREEMENT, DOCUMENT OR INSTRUMENT EXECUTED IN
CONNECTION WITH OR RELATING TO THIS NOTE, AND THE BORROWER AGREES THAT ANY SUCH
ACTION OR PROCEEDING MAY BE TRIED BEFORE A COURT AND NOT BEFORE A JURY.

         THE BORROWER ACKNOWLEDGES THAT IT HAS HAD THE ASSISTANCE OF COUNSEL IN
THE REVIEW AND EXECUTION OF THIS NOTE AND FURTHER ACKNOWLEDGES THAT THE MEANING
AND EFFECT OF THE CONFESSION OF JUDGMENT AND WAIVER OF JURY TRIAL HAVE BEEN
FULLY EXPLAINED TO SUCH BORROWER BY SUCH COUNSEL.

         This Note is being executed and delivered in the Commonwealth of
Pennsylvania and shall be governed by and construed in accordance with the laws
of the Commonwealth of Pennsylvania. Except where the context otherwise
requires, the term "Lender" shall be deemed to include any subsequent holder of
this Note.



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         IN WITNESS WHEREOF, the undersigned, by its duly authorized officer and
intending to be legally bound, has duly executed this Note this __ day of March,
2004.

ATTEST:                                 SELAS CORPORATION OF AMERICA


                                        By:                              (SEAL)
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Name:                                   Name:
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Title:
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