Exhibit
        10.39


    

    
      	
              

            	
              Master
                Revolving Note

            
	
              Variable
                Rate-Maturity Date-Optional Advances (Business and Commercial Loans
                Only)

            


    

    


    
      	
              AMOUNT

               

              $500,000

            	
              NOTE
                DATE

               

              December
                18, 2007

            	
              MATURITY
                DATE

               

              December
                1, 2008

            	
              TAX
                IDENTIFICATION NUMBER

               

              95-3545701

            


    

    


    On
      the
      Maturity Date, as stated above, for value received, the undersigned promise(s)
      to pay to the order of Comerica Bank ("Bank"), at any office of the Bank in
      the
      State of Michigan, Five Hundred Thousand Dollars (U.S.) (or that portion of
      it
      advanced by the Bank and not repaid as later provided) with interest until
      maturity, whether by acceleration or otherwise, or until Default, as later
      defined, at a per annum rate equal to the Bank's prime rate from time to time
      in
      effect per annum, and after that at a rate equal to the rate of interest
      otherwise prevailing under this Note plus three percent (3%) per annum (but
      in
      no event in excess of the maximum rate permitted by law). The Bank's "prime
      rate" is that annual rate of interest so designated by the Bank and which is
      changed by the Bank from time to time. Interest rate changes will be effective
      for interest computation purposes as and when the Bank's prime rate changes.
      Interest shall be calculated on the basis of a 360-day year for actual number
      of
      days the principal is outstanding. Accrued interest on this Note shall be
      payable on the first day of each month commencing February, 2008, until the
      Maturity Date (set forth above) when all amounts outstanding under this Note
      shall be due and payable in full. If the frequency of interest payments is
      not
      otherwise specified, accrued interest on this Note shall be payable monthly
      on
      the first day of each month. If any payment of principal or interest under
      this
      Note shall be payable on a day other than a day on which the Bank is open for
      business, this payment shall be extended to the next succeeding business day
      and
      interest shall be payable at the rate specified in this Note during this
      extension. A late payment charge equal to five percent (5%) of each late payment
      may be charged on any payment not received by the Bank within ten (10) calendar
      days after the payment due date, but acceptance of payment of this charge shall
      not waive any Default under this Note.

     

    The
      principal amount payable under this Note shall be the sum of all advances made
      by the Bank to or at the request of the undersigned, less principal payments
      actually received in cash by the Bank. The books and records of the Bank shall
      be the best evidence of the principal amount and the unpaid interest amount
      owing at any time under this Note and shall be conclusive absent manifest error.
      No interest shall accrue under this Note until the date of the first advance
      made by the Bank; after that interest on all advances shall accrue and be
      computed on the principal balance outstanding from time to time under this
      Note
      until the same is paid in full. At no time shall the Bank be under any
      obligation to make any advances to the undersigned pursuant to this Note
      (notwithstanding anything expressed or implied in this Note or elsewhere to
      the
      contrary, including without limit if the Bank supplies the undersigned with
      a
      borrowing formula) and the Bank, at any time and from time to time, without
      notice, and in its sole discretion, may refuse to make advances to the
      undersigned without incurring any liability due to this refusal and without
      affecting the undersigned's liability under this Note for any and all amounts
      advanced.

     

    This
      Note
      and any other indebtedness and liabilities of any kind of the undersigned (or
      any of them) to the Bank, and any and all modifications, renewals or extensions
      of it, whether joint or several, contingent or absolute, now existing or later
      arising, and however evidenced (collectively "Indebtedness"), are secured by
      and
      the Bank is granted a security interest in all items deposited in any account
      of
      any of the undersigned with the Bank and by all proceeds of these items (cash
      or
      otherwise), all account balances of any of the undersigned from time to time
      with the Bank, by all property of any of the undersigned from time to time
      in
      the possession of the Bank and by any other collateral, rights and properties
      described in each and every deed of trust, mortgage, security agreement, pledge,
      assignment and other security or collateral agreement which has been, or will
      at
      any time(s) later be, executed by any (or all) of the undersigned to or for
      the
      benefit of the Bank (collectively "Collateral"). Notwithstanding the above,
      (i)
      to the extent that any portion of the Indebtedness is a consumer loan, that
      portion shall not be secured by any deed of trust, mortgage on or other security
      interest in any of the undersigned's principal dwelling or in any of the
      undersigned's real property which is not a purchase money security interest
      as
      to that portion, unless expressly provided to the contrary in another place,
      or
      (ii) if the undersigned (or any of them) has(have) given or give(s) Bank a
      deed
      of trust or mortgage covering California real property, that deed of trust
      or
      mortgage shall not secure this Note or any other indebtedness of the undersigned
      (or any of them), unless expressly provided to the contrary in another
      place.

     

    If
      the
      undersigned (or any of them) or any guarantor under a guaranty of all or part
      of
      the Indebtedness ("guarantor") (a) fail(s) to pay any of the Indebtedness when
      due, by maturity, acceleration or otherwise, or fail(s) to pay any Indebtedness
      owing on a demand basis upon demand; or (b) fail(s) to comply with any of the
      terms or provisions of any agreement between the undersigned (or any of them)
      or
      any such guarantor and the Bank; or (c) become(s) insolvent or the subject
      of a
      voluntary or involuntary proceeding in bankruptcy, or a reorganization,
      arrangement or creditor composition proceeding, (if a business entity) cease(s)
      doing business as a going concern, (if a natural person) die(s) or become(s)
      incompetent, (if a partnership) dissolve(s) or any general partner of it dies,
      becomes incompetent or becomes the subject of a bankruptcy proceeding or (if
      a
      corporation or a limited liability company) is the subject of a dissolution,
      merger or consolidation; or (d) if any warranty or representation made by any
      of
      the undersigned or any guarantor in connection with this Note or any of the
      Indebtedness shall be discovered to be untrue or incomplete; or (e) if there
      is
      any termination, notice of termination, or breach of any guaranty, pledge,
      collateral assignment or subordination agreement relating to all or any part
      of
      the Indebtedness; or (f) if there is any failure by any of the undersigned
      or
      any guarantor to pay when due any of its indebtedness (other than to the Bank)
      or in the observance or performance of any term, covenant or condition in any
      document evidencing, securing or relating to such indebtedness; or (g) if the
      Bank deems itself insecure believing that the prospect of payment of this Note
      or any of the Indebtedness is impaired or shall fear deterioration, removal
      or
      waste of any of the Collateral; or (h) if there is filed or issued a levy or
      writ of attachment or garnishment or other like judicial process upon the
      undersigned (or any of them) or any guarantor or any of the Collateral,
      including without limit, any accounts of the undersigned (or any of them) or
      any
      guarantor with the Bank, then the Bank, upon the occurrence of any of these
      events (each a "Default"), may at its option and without prior notice to the
      undersigned (or any of them), declare any or all of the Indebtedness to be
      immediately due and payable (notwithstanding any provisions contained in the
      evidence of it to the contrary), sell or liquidate all or any portion of the
      Collateral, set off against the Indebtedness any amounts owing by the Bank
      to
      the undersigned (or any of them), charge interest at the default rate provided
      in the document evidencing the relevant Indebtedness and exercise any one or
      more of the rights and remedies granted to the Bank by any agreement with the
      undersigned (or any of them) or given to it under applicable law. All payments
      under this Note shall be in immediately available United States funds, without
      setoff or counterclaim.

     

    
      
        
        

      

      
        
        

        
          

        

      

      
        
        

      

    

     

    If
      this
      Note is signed by two or more parties (whether by all as makers or by one or
      more as an accommodation party or otherwise), the obligations and undertakings
      under this Note shall be that of all and any two or more jointly and also of
      each severally. This Note shall bind the undersigned, and the undersigned's
      respective heirs, personal representatives, successors and assigns. The
      undersigned waive(s) presentment, demand, protest, notice of dishonor, notice
      of
      demand or intent to demand, notice of acceleration or intent to accelerate,
      and
      all other notices and agree(s) that no extension or indulgence to the
      undersigned (or any of them) or release, substitution or nonenforcement of
      any
      security, or release or substitution of any of the undersigned, any guarantor
      or
      any other party, whether with or without notice, shall affect the obligations
      of
      any of the undersigned. The undersigned waive(s) all defenses or right to
      discharge available under Section 3-605 of the Michigan Uniform Commercial
      Code
      and waive(s) all other suretyship defenses or right to discharge. The
      undersigned agree(s) that the Bank has the right to sell, assign, or grant
      participations or any interest in, any or all of the Indebtedness, and that,
      in
      connection with this right, but without limiting its ability to make other
      disclosures to the full extent allowable, the Bank may disclose all documents
      and information which the Bank now or later has relating to the undersigned
      or
      the Indebtedness. The undersigned agree(s) that the Bank may provide information
      relating to this Note or relating to the undersigned to the Bank's parent,
      affiliates, subsidiaries and service providers.

     

    The
      undersigned agree(s) to reimburse the holder or owner of this Note upon demand
      for any and all costs and expenses (including without limit, court costs, legal
      expenses and reasonable attorney fees, whether inside or outside counsel is
      used, whether or not suit is instituted and, if suit is instituted, whether
      at
      the trial court level, appellate level, in a bankruptcy, probate or
      administrative proceeding or otherwise) incurred in collecting or attempting
      to
      collect this Note or incurred in any other matter or proceeding relating to
      this
      Note.

     

    The
      undersigned acknowledge(s) and agree(s) that there are no contrary agreements,
      oral or written, establishing a term of this Note and agree(s) that the terms
      and conditions of this Note may not be amended, waived or modified except in
      a
      writing signed by an officer of the Bank expressly stating that the writing
      constitutes an amendment, waiver or modification of the terms of this Note.
      As
      used in this Note, the word "undersigned" means, individually and collectively,
      each maker, accommodation party, indorser and other party signing this Note
      in a
      similar capacity. If any provision of this Note is unenforceable in whole or
      part for any reason, the remaining provisions shall continue to be effective.
      THIS
      NOTE IS MADE IN THE STATE OF MICHIGAN AND SHALL BE GOVERNED BY AND CONSTRUED
      IN
      ACCORDANCE WITH THE INTERNAL LAWS OF THE STATE OF MICHIGAN, WITHOUT REGARD
      TO
      CONFLICT OF LAWS PRINCIPLE.

     

    THE
      MAXIMUM INTEREST RATE SHALL NOT EXCEED 25% PER ANNUM, OR THE HIGHEST APPLICABLE
      USURY CEILING, WHICHEVER IS LESS.

     

    
      
        
        

      

      
        2

        
          

        

      

      
        
        

      

    


    THE
      UNDERSIGNED AND THE BANK ACKNOWLEDGE THAT THE RIGHT TO TRIAL BY JURY IS A
      CONSTITUTIONAL ONE, BUT THAT IT MAY BE WAIVED. EACH PARTY, AFTER CONSULTING
      (OR
      HAVING HAD THE OPPORTUNITY TO CONSULT) WITH COUNSEL OF THEIR CHOICE, KNOWINGLY
      AND VOLUNTARILY, AND FOR THEIR MUTUAL BENEFIT, WAIVES ANY RIGHT TO TRIAL BY
      JURY
      IN THE EVENT OF LITIGATION REGARDING THE PERFORMANCE OR ENFORCEMENT OF, OR
      IN
      ANY WAY RELATED TO, THIS NOTE OR THE INDEBTEDNESS.

    

      
        	
                DATAMETRICS
                  CORPORATION,

              	 	 
	
                a
                  Delaware Corporation

              	
                By:
                  /s/
                  Gary Herman 

                
                  

                
    
                  SIGNATURE OF	
                Its: 
                  Chairman
                  

                
                  

                

                
                

                TITLE
                  (if applicable)

              


      

    

     

    
      
        	
                1717
                  Diplomacy Row

              	
                Orlando

              	
                Florida

              	
                32809

              
	
                STREET
                  ADDRESS

              	
                CITY

              	
                STATE

              	
                ZIP

              


      

    

     

    
      	
              For
                Bank Use Only

            	
              CCAR#

            
	 	 
	
              LOAN
                OFFICER INITIALS

            	
              LOAN
                GROUP NAME

            	
              OBLIGOR
                NAME

              Datametrics
                Corporation

            
	 	 	 
	
              LOAN
                OFFICER ID. NO.

            	
              LOAN
                GROUP NO.

            	
              OBLIGOR
                NO.

            	
              NOTE
                NO.

            	
              AMOUNT

              $500,000

            


    

     

    
      
         

      

      
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