WAIVER AND AMENDMENT TO CONVERTIBLE SECURED PROMISSORY NOTE

Exhibit 10.52

WAIVER AND AMENDMENT TO

CONVERTIBLE SECURED PROMISSORY NOTE

This Amendment to Convertible Secured Promissory Note (this “Amendment”) is entered into as of December 27, 2007 by and between Catcher Holdings, Inc., a Delaware corporation (the “Company”), and the Purchasers (as defined below). This Amendment amends the Convertible Secured Promissory Notes (the “Notes”) issued pursuant to the each of the Note and Restricted Stock Purchase Agreements, dated as of April 4, 2007 and June 20, 2007 by and among the Company and the persons and entities listed on Exhibit A thereto (each a “Purchaser” and collectively, the “Purchasers”) (together the “Agreements”). Capitalized terms not otherwise defined herein shall have the meanings given in the Notes.

RECITALS

WHEREAS, the Company and the Purchasers are parties to the Notes;

Whereas, Section 11 of the Notes provide that all outstanding Notes may be amended with the written consent of the Company and Purchasers holding more than 50% of the aggregate Loan Amount outstanding under all Notes issued pursuant to the Agreements; and

WHEREAS, the Company and the holders of a majority of the aggregate Loan Amount outstanding under all Notes issued pursuant to the Agreements desire to amend the Notes as set forth herein.

NOW, THEREFORE, in consideration of the foregoing and of the mutual promises and covenants set forth herein, the parties agree as follows:

“Maturity. Unless sooner paid or converted in accordance with the terms hereof, the entire unpaid principal amount and all unpaid accrued interest shall become fully due and payable on the earlier of (a) unless extended pursuant to Section 7(a)(i) below, the date that is two hundred forty (240) days after the date hereof, (b) the closing of a Next Financing (as defined below), or (c) the acceleration of the maturity of this Note by the Holder upon the occurrence of an Event of Default (such earlier date, the “Maturity Date”).”

“(a) Conversion upon sale of Next Securities. In the event that the Company, at any time after the date of issuance of this Note and prior to the payment in full of this Note, shall issue and sell equity securities (the “Next Securities”) to investors for aggregate proceeds of at least $5,000,000 to the Company and at a price not less than $0.50 per share (a “Next Financing”), then the outstanding principal amount of this Note and all accrued but unpaid interest thereon shall automatically be converted at the closing of the Next

Securities, into Common Stock at a conversion price equal to the conversion price defined in Section 6(a)(i). In connection with such conversion, Holder agrees to execute and deliver to the Company any documents reasonably requested by the Company. As soon as is reasonably practicable after a conversion has been effected, the Company shall deliver to Holder a certificate or certificates representing the number of shares of Common Stock issuable by reason of such conversion pursuant to this Section 5 in such name or names and such denomination or denominations as Holder has specified.”

[Signature Page Follows]

IN WITNESS WHEREOF, the parties hereto have executed this Amendment as of the date first above written.

[SIGNATURE PAGE TO AMENDMENT TO CONVERTIBLE SECURED PROMISSORY NOTE]