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EXHIBIT 4.7

REVOLVING NOTE

|Executed as of the 31st day of July, 2000 |  | Amount $5,000,000.00
|----------------------------------------- |  | --------------------

FOR VALUE RECEIVED, the Undersigned promises to pay to the order ofLASALLE BUSINESS CREDIT,
INC. (hereinafter, together with any holder hereof, called "LaSalle"), at the main office of LaSalle, 135 South LaSalle Street, Chicago, Illinois 60603, the principal sum of FIVE MILLION and 00/100
DOLLARS ($5,000,000.00)plus the aggregate unpaid principal amount of all advances made by LaSalle to the Undersigned pursuant
to and in accordance with Paragraph 2 of the Loan Agreement (as hereinafter defined) in excess of such amount, or, if less, the aggregate unpaid principal amount of all advances made by LaSalle
to the Undersigned pursuant to and in accordance with Paragraph 2 of the Loan Agreement. The outstanding principal balance shall be payable in accordance with the terms and conditions in the
Loan Agreement. The Undersigned further promises to pay interest on the outstanding principal amount hereof on the dates and at the rates provided in the Loan Agreement from the date hereof until
payment in full hereof.

This
Revolving Note is referred to in and was delivered pursuant to that certain Loan and Security Agreement, as it may be amended from time to time, together with all exhibits
thereto, dated July 31, 2000, between LaSalle and the Undersigned (the "Loan Agreement"). All terms which are capitalized and used herein (which are not otherwise defined herein) shall have the
meanings ascribed to such terms in the Loan Agreement.

The
Undersigned hereby authorizes LaSalle to charge any account of the Undersigned for all sums due hereunder. If payment hereunder becomes due and payable on a Saturday, Sunday or
legal holiday under the laws of the United States or the State of Minnesota, the due date thereof shall be extended to the next succeeding business day, and interest shall be payable thereon at the
rate specified during such extension. Credit shall be given for payments made in the manner and at the times provided in the Loan Agreement. It is the intent of the parties that the rate of interest
and other charges to the Undersigned under this Revolving Note shall be lawful and shall be limited to the maximum nonusurious rate of interest permitted by law; therefore, if for any reason the
interest or other charges payable hereunder are found by a court of competent jurisdiction, in a final determination, to exceed the limit which LaSalle may lawfully charge the Undersigned, then the
obligation to pay interest or
other charges shall automatically be reduced to such limit and, if any amount in excess of such limit shall have been paid, then such amount shall be refunded to the Undersigned.

The
principal and all accrued interest hereunder may be prepaid by the Undersigned, in part or in full, at any time; provided, however, that if the Undersigned prepays all of the
Liabilities prior to the end of the Original Term or any Renewal Term, the Undersigned shall pay a prepayment fee as provided in the Loan Agreement.

The
Undersigned waives the benefit of any law that would otherwise restrict or limit LaSalle in the exercise of its right, which is hereby acknowledged, to set-off against
the Liabilities, without notice and at any time hereafter, any indebtedness matured or unmatured owing from LaSalle to the Undersigned. The Undersigned waives every defense, counterclaim or setoff
which the Undersigned may now have or hereafter may have to any action by LaSalle in enforcing this Note and/or any of the other Liabilities, or in enforcing LaSalle's rights in the Collateral and
ratifies and confirms whatever LaSalle may do pursuant to the terms hereof and of the Loan Agreement and with respect to the Collateral and agrees that LaSalle shall not be liable for any error in
judgment or mistakes of fact or law.

The
Undersigned, any other party liable with respect to the Liabilities and any and all endorsers and accommodation parties, and each one of them, if more than one, waive any and all
presentment, demand, notice of dishonor, protest, and all other notices and demands in connection with the enforcement of LaSalle's rights hereunder.

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The loan evidenced hereby has been made and this Note has been delivered at Chicago, Illinois.THIS NOTE SHALL BE GOVERNED AND CONTROLLED BY THE INTERNAL LAWS
OF THE STATE OF MINNESOTA AS TO INTERPRETATION, ENFORCEMENT, VALIDITY, CONSTRUCTION, EFFECT, AND IN ALL OTHER RESPECTS, INCLUDING WITHOUT LIMITATION, THE LEGALITY OF THE INTEREST RATE AND OTHER
CHARGES, and shall be binding upon the Undersigned and the Undersigned's heirs, legal representatives, successors and assigns. If this Note contains any blanks when executed by
the Undersigned, LaSalle is hereby authorized, without notice to the Undersigned to complete any such blanks according to the terms upon which the loan or loans were granted. Wherever possible, each
provision of this Note shall be interpreted in such manner as to be effective and valid under applicable law, but if any provision of this Note shall be prohibited by or be invalid under such law,
such provision shall be severable, and be ineffective to the extent of such prohibition or invalidity, without invalidating the remaining provisions of this Note, the term "Undersigned" as used herein
shall mean all parties signing this Note, and each one of them, and all
such parties, their respective heirs, executors, administrators, successors and assigns, shall be jointly and severally obligated hereunder.

To
induce LaSalle to make the loan evidenced by this Note, the Undersigned (i) irrevocably agrees that, subject to LaSalle's sole and absolute election, all actions arising
directly or indirectly as a result or in consequence of this Note or any other agreement with LaSalle, or the Collateral, shall be instituted and litigated only in courts having situs in the County of
Hennepin, Minnesota, (ii) hereby consents to the exclusive jurisdiction and venue of any State or Federal Court located and having its situs in said city, and (iii) waives any objection
based on forum non-conveniens.IN ADDITION, THE UNDERSIGNED HEREBY WAIVES TRIAL BY JURY IN ANY ACTION OR PROCEEDING WHICH PERTAINS DIRECTLY OR INDIRECTLY TO THIS
NOTE, THE LIABILITIES, THE COLLATERAL, ANY ALLEGED TORTIOUS CONDUCT BY THE UNDERSIGNED OR LASALLE OR WHICH IN ANY WAY, DIRECTLY OR INDIRECTLY, ARISES OUT OF OR RELATES TO THE RELATIONSHIP BETWEEN THE
UNDERSIGNED AND LASALLE, and consents that service of process may be made in accordance with the Loan Agreement; and service so made shall be completed five (5) days
after the same has been deposited in the U.S. mails as aforesaid.

As
used herein, all provisions shall include the masculine, feminine, neuter, singular and plural thereof, wherever the context and facts require such construction and in particular
the word "Undersigned" shall be so construed.

IN WITNESS WHEREOF, the Undersigned has executed this Note on the date above set forth.

| |  | HEI, INC.                                                    
| |  | -------------------------------------------------------------
| |  | /s/ANTHONY J. FANTBy: Anthony J. Fant
Title: Chairman and CEO

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ACKNOWLEDGMENT OF SIGNATURE

|STATE OF MINNESOTA |  | )    
|------------------ |  | -----
|                   |  | ) SS.
|COUNTY OF RAMSEY   |  | )    

I,
James W. Dierking, a Notary Public in and for the state and county aforesaid, do hereby certify that before me this day personally appeared Anthony J. Fant, Chairman and CEO of the
HEI, Inc., a Minnesota corporation, known to me to be the same person whose name is subscribed to the foregoing Revolving Note, and acknowledged to me that he executed and delivered the
foregoing Revolving Note as his free and voluntary act, for the uses set forth therein.

IN WITNESS WHEREOF, I have hereunto set my hand and official seal this 27th day of July, 2000.

|[SEAL] |  | /s/JAMES W. DIERKINGNotary Public
|------ |  | ---------------------------------
|       |  | My Commission Expires
1/31/05    

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