EXHIBIT
      10.5

    


    14%
      PROMISSORY NOTE

    


    
      	$500,000	
              August
                16, 2007

            


    

     

    FOR
      VALUE
      RECEIVED, GigaBeam Corporation, a Delaware corporation (the “Maker”),
      with
      its primary offices located at 4021 Stirrup Creek Drive, Suite 400, Durham,
      NC
      27703, promises to pay to the order of Midsummer Investment, Ltd., or its
      registered assigns (the “Payee”),
      upon
      the terms set forth below, the principal sum of Five Hundred Thousand Dollars
      ($500,000) plus interest on the unpaid principal sum outstanding at the rate
      of
      14% per annum (this “Note”).

    


    Notwithstanding
      anything herein to the contrary, in the event of any liquidation, insolvency,
      bankruptcy, reorganization, or similar proceedings relating to the Maker, all
      sums payable on the Senior Convertible Notes issued on January 28, 2005 and
      February 1, 2005 (“Senior
      Notes”),
      shall
      first be paid in full, with interest, if any, before any cash payment is made
      upon this Note, and, in any such event, any cash payment which shall be made
      in
      respect of this Note shall be paid over to the holders of the Senior Notes
      for
      application to the payment thereof, unless and until the obligations under
      the
      Senior Notes shall have been paid and satisfied in full. 

    


    1. Payments.

    


    (a)
       The
      full
      amount of principal and accrued interest under this Note shall be due August
      16,
      2008 (the “Maturity
      Date”),
      unless due earlier in accordance with the terms of this Note.

    


    (b)
       The
      Maker
      shall pay interest to the Payee on the aggregate then outstanding principal
      amount of this Note at the rate of 14% per annum, payable on the Maturity
      Date.

    


    (c)
       All
      overdue accrued and unpaid principal and interest to be paid hereunder shall
      entail a late fee at the rate of 22% per annum (or such lower maximum amount
      of
      interest permitted to be charged under applicable law) which will accrue daily,
      from the date such principal and/or interest is due hereunder through and
      including the date of payment.

    


    (d) Absent
      the occurrence of an Event of Default (unless waived in writing by the Payee),
      the Maker may prepay this Note for 100% of the full principal amount of this
      Note, together with all accrued interest thereon, at any time prior to the
      Maturity Date.


    
      
         

        
        

      

      
        
        

        
          

        

      

      
        
        

      

    

    


    2.
      Events
      of Default.

    


    (a)
       “Event
      of Default”,
      wherever used herein, means any one of the following events (whatever the reason
      and whether it shall be voluntary or involuntary or effected by operation of
      law
      or pursuant to any judgment, decree or order of any court, or any order, rule
      or
      regulation of any administrative or governmental body):

    


    (i)
       any
      default in the payment of the principal of, or the interest on, this Note,
      as
      and when the same shall become due and payable;

    


    (ii)
       Maker
      or
      any of its subsidiaries shall fail to observe or perform any of their respective
      obligations owed to Payee under this Note or any other covenant, agreement,
      representation or warranty contained in, or otherwise commit any breach
      hereunder or in any other agreement executed in connection herewith and such
      failure or breach shall not have been remedied within ten days after the date
      on
      which notice of such failure or breach shall have been delivered;

    


    (iii)
       Maker
      or
      any of its subsidiaries shall commence, or there shall be commenced against
      Maker or any subsidiary a case under any applicable bankruptcy or insolvency
      laws as now or hereafter in effect or any successor thereto, or Maker or any
      subsidiary commences any other proceeding under any reorganization, arrangement,
      adjustment of debt, relief of debtors, dissolution, insolvency or liquidation
      or
      similar law of any jurisdiction whether now or hereafter in effect relating
      to
      Maker or any subsidiary, or there is commenced against Maker or any subsidiary
      any such bankruptcy, insolvency or other proceeding which remains undismissed
      for a period of 60 days; or Maker or any subsidiary is adjudicated insolvent
      or
      bankrupt; or any order of relief or other order approving any such case or
      proceeding is entered; or Maker or any subsidiary suffers any appointment of
      any
      custodian or the like for it or any substantial part of its property which
      continues undischarged or unstayed for a period of 60 days; or Maker or any
      subsidiary makes a general assignment for the benefit of creditors; or Maker
      or
      any subsidiary shall call a meeting of its creditors with a view to arranging
      a
      composition, adjustment or restructuring of its debts; or Maker or any
      subsidiary shall by any act or failure to act expressly indicate its consent
      to,
      approval of or acquiescence in any of the foregoing; or any corporate or other
      action is taken by Maker or any subsidiary for the purpose of effecting any
      of
      the foregoing;

    


    (iv) After
      January 29, 2008, Maker or any subsidiary shall default for the first time
      in
      any of its respective obligations under any other note or any mortgage, credit
      agreement or other facility, indenture agreement, factoring agreement or other
      instrument under which there may be issued, or by which there may be secured
      or
      evidenced any indebtedness for borrowed money or money due under any long term
      leasing or factoring arrangement of Maker or any subsidiary, whether such
      indebtedness now exists or shall hereafter be created and such default shall
      result in such indebtedness becoming or being declared due and payable prior
      to
      the date on which it would otherwise become due and payable;


    
      
         

        
        

      

      
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    (v)
      any
      monetary judgment, writ or similar final process shall be entered or filed
      against the Maker, any subsidiary or any of their respective property or other
      assets for more than $300,000, and such judgment, writ or similar final process
      shall remain unvacated, unbonded or unstayed for a period of 15 calendar
      days.

    


    (vi)
       Maker
      shall (a) be a party to any Change of Control Transaction (as defined below),
      (b) agree to sell or dispose all or in excess of 33% of its assets in one or
      more transactions (whether or not such sale would constitute a Change of Control
      Transaction), (c) redeem or repurchase more than a de minimis number of shares
      of Common Stock or other equity securities of Maker, or (d) other than regularly
      scheduled payments of dividends to the holders of the Maker’s Series A, Series
      B, Series C and Series D Preferred Stock, make any distribution or declare
      or
      pay any dividends (in cash or other property, other than common stock) on,
      or
      purchase, acquire, redeem, or retire any of Maker's capital stock, of any class,
      whether now or hereafter outstanding. “Change of Control Transaction” means the
      occurrence of any of: (i) an acquisition after the date hereof by an individual
      or legal entity or “group” (as described in Rule 13d-5(b)(1) promulgated under
      the Securities Exchange Act of 1934, as amended) of effective control (whether
      through legal or beneficial ownership of capital stock of Maker, by contract
      or
      otherwise) of in excess of 33% of the voting securities of Maker, (ii) a
      replacement at one time or over time of more than one-half of the members of
      Maker's board of directors which is not approved by a majority of those
      individuals who are members of the board of directors on the date hereof (or
      by
      those individuals who are serving as members of the board of directors on any
      date whose nomination to the board of directors was approved by a majority
      of
      the members of the board of directors who are members on the date hereof),
      (iii)
      the merger of Maker with or into another entity that is not wholly-owned by
      Maker, consolidation or sale of 33% or more of the assets of Maker in one or
      a
      series of related transactions, or (iv) the execution by Maker of an agreement
      to which Maker is a party or by which it is bound, providing for any of the
      events set forth above in (i), (ii) or (iii). This clause shall not include
      the
      recapitalization proposed to investors in December 2007.


    
      
         

        
        

      

      
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    (b)
      If
      any Event of Default occurs (unless waived in writing by the Payee), 115% of
      the
      full principal amount of this Note, together with all accrued interest thereon,
      shall become, at the Payee's election, immediately due and payable in cash.
      Commencing 5 days after the occurrence of any Event of Default that results
      in
      the acceleration of this Note, the interest rate on this Note shall accrue
      at
      the rate of 22% per annum, or such lower maximum amount of interest permitted
      to
      be charged under applicable law. The Payee need not provide and Maker hereby
      waives any presentment, demand, protest or other notice of any kind, and the
      Payee may immediately and without expiration of any grace period enforce any
      and
      all of its rights and remedies hereunder and all other remedies available to
      it
      under applicable law. Such declaration may be rescinded and annulled by Payee
      at
      any time prior to payment hereunder. No such rescission or annulment shall
      affect any subsequent Event of Default or impair any right consequent
      thereon.

    


    3.
       Most
      Favored Nations.
      The
      Payee shall have the right, in its sole discretion, to convert the principal
      balance of this Note then outstanding plus accrued but unpaid interest, in
      whole
      or in part, into securities of the Maker (or its successor or parent) being
      issued in any private or public offering of equity securities or indebtedness
      of
      the Maker (or its successor or parent) consummated while this Note is
      outstanding, upon the terms and conditions of such offering, at a rate equal
      to,
      for each $1 of principal amount of this Note surrendered, $1 of new
      consideration offered for such securities. By way of example, if the Payee
      wishes to surrender $100,000 principal amount of this Note to the Maker as
      consideration for the purchase of new securities or indebtedness, the Payee
      shall receive, and the Maker shall issue, $100,000 of new securities (including
      any securities or other consideration issued or paid to the investors in such
      offer in connection with the purchase of securities) or indebtedness to the
      Payee, otherwise on the same terms and conditions as the other
      participants.

    


    4.
       Negative
      Covenants.
       So
      long
      as any portion of this Note is outstanding, the Maker will not and will not
      permit any of its Subsidiaries to directly or indirectly, unless consented
      to in
      writing by the Payee:

    


    a) other
      than Permitted Indebtedness, enter into, create, incur, assume, guarantee or
      suffer to exist any indebtedness for borrowed money of any kind, including
      but
      not limited to, a guarantee, on or with respect to any of its property or assets
      now owned or hereafter acquired or any interest therein or any income or profits
      therefrom;

     

    b) other
      than Permitted Liens, enter into, create, incur, assume or suffer to exist
      any
      liens of any kind, on or with respect to any of its property or assets now
      owned
      or hereafter acquired or any interest therein or any income or profits
      therefrom;

    


    c) amend
      its
      certificate of incorporation, bylaws or other charter documents so as to
      adversely affect any rights of the Payee other than to increase the number
      of
      authorized common shares;


    
      
         

        
        

      

      
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    d) except
      as
      contractually required by the Maker as of the date of issuance of this Note,
      repay, repurchase or offer to repay, repurchase or otherwise acquire more than
      a
      de minimis number of securities;

    


    e) enter
      into any agreement with respect to any of the foregoing;
      or

    


    f) other
      than in respect of the Maker’s Series A, Series B, Series C and Series D
      Preferred Stock, pay cash dividends or distributions on any equity securities
      of
      the Maker.

    


    “Permitted
      Indebtedness”
      shall
      mean (a)
      the
      indebtedness of the Maker existing on the date of issuance of this Note, (b)
      lease obligations and purchase money indebtedness incurred in connection with
      the acquisition of capital assets and lease obligations with respect to newly
      acquired or leased assets (c) indebtedness
      incurred by the Maker that does not mature or require payments of principal
      prior to the Maturity Date of this Note and is made expressly subordinate in
      right of payment to the indebtedness evidenced by this Note, as reflected in
      a
      written agreement acceptable to the Payee and approved by the Payee in writing,
      (d) trade receivables in the ordinary course of business, and (e) up to
      $5,000,000 (five million dollars) in new financing.

    


    “Permitted
      Lien”
shall
      mean the individual and collective reference to the following: (a) liens for
      taxes, assessments and other governmental charges or levies not yet due or
      liens
      for taxes, assessments and other governmental charges or levies being contested
      in good faith and by appropriate proceedings for which adequate reserves (in
      the
      good faith judgment of the management of the Maker) have been established in
      accordance with generally accepted accounting procedures, (b) liens imposed
      by
      law which were incurred in the ordinary course of business, such as carriers’,
      warehousemen’s and mechanics’ liens, statutory landlords’ liens, and other
      similar liens arising in the ordinary course of business, and (x) which do
      not
      individually or in the aggregate materially detract from the value of such
      property or assets or materially impair the use thereof in the operation of
      the
      business of the Maker and its consolidated subsidiaries or (y) which are being
      contested in good faith by appropriate proceedings, which proceedings have
      the
      effect of preventing the forfeiture or sale of the property or asset subject
      to
      such lien and (c) liens of the Maker existing on the date of issuance of this
      Note, including liens incurred in connection with the Permitted
      Indebtedness.

    


    The
      recapitalization proposed to investors in December 2007 is excluded from this
      Section 4.

    


    5. No
      Waiver of Payee’s Rights.
      All
      payments of principal and interest shall be made without setoff, deduction
      or
      counterclaim. No delay or failure on the part of the Payee in exercising any
      of
      its options, powers or rights, nor any partial or single exercise of its
      options, powers or rights shall constitute a waiver thereof or of any other
      option, power or right, and no waiver on the part of the Payee of any of its
      options, powers or rights shall constitute a waiver of any other option, power
      or right. Maker hereby waives presentment of payment, protest, and all notices
      or demands in connection with the delivery, acceptance, performance, default
      or
      endorsement of this Note. Acceptance by the Payee of less than the full amount
      due and payable hereunder shall in no way limit the right of the Payee to
      require full payment of all sums due and payable hereunder in accordance with
      the terms hereof.


    
      
         

        
        

      

      
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    6.
       Modifications.
      No term
      or provision contained herein may be modified, amended or waived except by
      written agreement or consent signed by the party to be bound
      thereby.

    


    7.
       Cumulative
      Rights and Remedies; Usury.
      The
      rights and remedies of Payee expressed herein are cumulative and not exclusive
      of any rights and remedies otherwise available under this Note or applicable
      law
      (including at equity). The election of Payee to avail itself of any one or
      more
      remedies shall not be a bar to any other available remedies, which Maker agrees
      Payee may take from time to time. If it shall be found that any interest due
      hereunder shall violate applicable laws governing usury, the applicable rate
      of
      interest due hereunder shall be reduced to the maximum permitted rate of
      interest under such law.

    


    8.
       Use
      of
      Proceeds.
      Maker
      shall use the proceeds from this Note hereunder for working capital purposes
      and
      not for the satisfaction of any portion of Maker’s or subsidiary’s debt (other
      than payment of trade payables in the ordinary course of Maker's business and
      prior practices), to redeem any of Maker’s or subsidiary’s equity or
      equity-equivalent securities or to settle any outstanding
      litigation.

    


    9.
       Collection
      Expenses.
      If
      Payee shall commence an action or proceeding to enforce this Note, then Maker
      shall reimburse Payee for its costs of collection and reasonable attorneys
      fees
      incurred with the investigation, preparation and prosecution of such action
      or
      proceeding.

    


    10.
       Severability.
      If any
      provision of this Note is declared by a court of competent jurisdiction to
      be in
      any way invalid, illegal or unenforceable, the balance of this Note shall remain
      in effect, and if any provision is inapplicable to any person or circumstance,
      it shall nevertheless remain applicable to all other persons and circumstances.
      If it shall be found that any interest or other amount deemed interest due
      hereunder shall violate applicable laws governing usury, the applicable rate
      of
      interest due hereunder shall automatically be lowered to equal the maximum
      permitted rate of interest.

    


    11.
       Successors
      and Assigns.
      This
      Note shall be binding upon Maker and its successors and shall inure to the
      benefit of the Payee and its successors and assigns. The term "Payee" as used
      herein, shall also include any endorsee, assignee or other holder of this
      Note.


    
      
         

        
        

      

      
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    12.
       Lost
      or Stolen Promissory Note.
      If this
      Note is lost, stolen, mutilated or otherwise destroyed, Maker shall execute
      and
      deliver to the Payee a new promissory note containing the same terms, and in
      the
      same form, as this Note. In such event, Maker may require the Payee to deliver
      to Maker an affidavit of lost instrument and customary indemnity in respect
      thereof as a condition to the delivery of any such new promissory
      note.

    


    13.
       Due
      Authorization.
      This
      Note has been duly authorized, executed and delivered by Maker and is the legal
      obligation of Maker, enforceable against Maker in accordance with its terms
      except as limited by general equitable principles and applicable bankruptcy,
      insolvency, reorganization, moratorium and other laws of general application
      affecting enforcement of creditors’ rights generally. No consent of any other
      party and no consent, license, approval or authorization of, or registration
      or
      declaration with, any governmental authority, bureau or agency is required
      in
      connection with the execution, delivery or performance by the Maker, or the
      validity or enforceability of this Note other than such as have been met or
      obtained. The execution, delivery and performance of this Note and all other
      agreements and instruments executed and delivered or to be executed and
      delivered pursuant hereto or thereto or the securities issuable upon conversion
      of this Note will not violate any provision of any existing law or regulation
      or
      any order or decree of any court, regulatory body or administrative agency
      or
      the certificate of incorporation or by-laws of the Maker or any mortgage,
      indenture, contract or other agreement to which the Maker is a party or by
      which
      the Maker or any property or assets of the Maker may be bound.

    


    14.
       Governing
      Law.
      All
      questions concerning the construction, validity, enforcement and interpretation
      of this Note shall be governed by and construed and enforced in accordance
      with
      the internal laws of the State of New York, without regard to the principles
      of
      conflicts of law thereof. Each of Maker and Payee agree that all legal
      proceedings concerning the interpretations, enforcement and defense of this
      Note
      shall be commenced in the state and federal courts sitting in the City of New
      York, Borough of Manhattan (the "New York Courts"). Each of Maker and Payee
      hereby irrevocably submit to the exclusive jurisdiction of the New York Courts
      for the adjudication of any dispute hereunder (including with respect to the
      enforcement of this Note), and hereby irrevocably waives, and agrees not to
      assert in any suit, action or proceeding, any claim that it is not personally
      subject to the jurisdiction of any such court, that such suit, action or
      proceeding is improper. Each of Maker and Payee hereby irrevocably waive
      personal service of process and consents to process being served in any such
      suit, action or proceeding by mailing a copy thereof via registered or certified
      mail or overnight delivery (with evidence of delivery) to the other at the
      address in effect for notices to it under this Note and agrees that such service
      shall constitute good and sufficient service of process and notice thereof.
      Nothing contained herein shall be deemed to limit in any way any right to serve
      process in any manner permitted by law. Each of Maker and Payee hereby
      irrevocably waive, to the fullest extent permitted by applicable law, any and
      all right to trial by jury in any legal proceeding arising out of or relating
      to
      this Note or the transactions contemplated hereby.


    
      
         

        
        

      

      
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    15. Notice. 
      Any and
      all notices or other communications or deliveries to be provided by the Payee
      hereunder, including, without limitation, any conversion notice, shall be in
      writing and delivered personally, by facsimile, sent by a nationally recognized
      overnight courier service or sent by certified or registered mail, postage
      prepaid, addressed to the Maker, or such other address or facsimile number
      as
      the Maker may specify for such purposes by notice to the Payee delivered in
      accordance with this paragraph. Any and all notices or other communications
      or
      deliveries to be provided by the Maker hereunder shall be in writing and
      delivered personally, by facsimile, sent by a nationally recognized overnight
      courier service or sent by certified or registered mail, postage prepaid,
      addressed to the Payee at the address of the Payee appearing on the books of
      the
      Maker, or if no such address appears, at the principal place of business of
      the
      Payee. Any notice or other communication or deliveries hereunder shall be deemed
      given and effective on the earliest of (i) the date of transmission if delivered
      by
      hand
      or by telecopy that has been confirmed as received by 5:00 P.M. on a business
      day,
      (ii)
one
      business day after being sent by nationally recognized overnight courier or
      received by telecopy after 5:00 P.M. on any day,
      or
      (iii) five
      business
      days
      after being sent by certified or registered mail, postage and charges prepaid,
      return receipt requested.

    


    16.
      Public Disclosure.
      The
      Maker shall, within four business days following the date hereof, issue a
      Current Report on Form 8-K, reasonably acceptable to the Payee, disclosing
      the
      material terms of the transactions contemplated hereby, and shall attach this
      Note thereto and other agreements entered into in connection herewith. The
      Maker
      shall consult with the Payee in issuing any other press releases with respect
      to
      the transactions contemplated hereby.

    


    The
      undersigned signs this Note as a maker and not as a surety or guarantor or
      in
      any other capacity.

    


    
      	 	
              GIGABEAM
                CORPORATION

            	 
	 	 	 	 
	 	
              By:
                

            	
              /s/
                S. Jay Lawrence

            	 
	 	
              Name:

            	
              S.
                Jay Lawrence

            	 
	 	
              Title:

            	
              Chief
                Executive Officer

            	 


    

     

    
      
         

        
        

      

      
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