SECURED BUSINESS PROMISSORY NOTE

Exhibit 4.2

SECURED BUSINESS PROMISSORY NOTE

On or before August 30, 2009, BALLANTYNE OF OMAHA, INC. (“Maker”) promises to pay to the order of FIRST NATIONAL BANK OF OMAHA (“Lender”) the principal sum hereof, which shall be the lesser of Nine Million Four Hundred Thousand Dollars ($9,400,000.00), or so much thereof as may have been advanced by Lender pursuant to the Revolving Credit Agreement dated as of March 10, 2003, as amended, modified, supplemented and restated from time to time (the “Agreement”) between Maker and Lender. All capitalized terms not defined herein shall have their respective meanings as set forth in the Agreement.

Interest shall accrue on the principal sum hereof outstanding from time to time at a floating per annum interest rate equal to the Interim Revolving Credit Rate. The Interim Revolving Credit Rate will be adjusted on each Adjustment Date.

Interest shall accrue from and after the date of advance to the date of repayment and shall be calculated based on a year of 360 days, and actual days elapsed. Notwithstanding anything to the contrary elsewhere herein, after an Event of Default has occurred interest shall accrue on the entire outstanding balance of principal and interest on all indebtedness hereunder at a fluctuating rate equal to the Default Rate. Interest shall be due no later than the tenth day of each month.

The aggregate principal balance outstanding under this Note together with all accrued but unpaid interest thereon shall be due on the Interim Facility Termination Date. All obligations of Maker under this Note shall be payable in immediately available funds in lawful money of the United States of America at the principal office of Lender in Omaha, Nebraska or at such other address as may be designated by Lender in writing. In the event that a payment day is not a Business Day, the payment shall be due on the next succeeding Business Day.

Maker may at any time prepay the principal amount outstanding under this Note if Maker has given Lender at least two (2) Business Day’s prior written notice of its intention to make such prepayment. Any such prepayment may be made without penalty.

All obligations of Maker hereunder shall be secured by a first security interest in the Collateral, as more specifically described in the Security Agreement, the Pledge Agreement and Control Agreement, subject to liens permitted thereunder.

GENERAL TERMS

Maker’s liability for any amounts owed under this Note and the other Operative Documents (the “Obligations”) shall not be affected by any of the following:

Acceptance or retention by Lender of other property or interests as security for the Obligations, or for the liability of any person other than a Maker with respect to the Obligations;

The release of all or any of the Collateral or other security for any of the Obligations to any Maker; or