Form of Letter to Clients

THE OFFER AND WITHDRAWAL RIGHTS WILL EXPIRE AT 12:00 MIDNIGHT, NEW YORK CITY TIME, ON FRIDAY, JUNE 20, 2008, UNLESS THE OFFER IS EXTENDED (SUCH DATE AND TIME, AS IT MAY BE EXTENDED, THE “EXPIRATION DATE”).

Enclosed for your information is an Offer to Purchase, dated May 22, 2008 (as it may be amended or supplemented from time to time, the “Offer to Purchase”), and the related Letter of Transmittal (as it may be amended or supplemented from time to time, the “Letter of Transmittal” and, together with the Offer to Purchase, the “Offer”), relating to the offer by Comtech TA Corp., a Delaware corporation (“Purchaser”) and a wholly-owned subsidiary of Comtech Telecommunications Corp., a Delaware corporation (“Comtech”), to purchase all outstanding shares of common stock, $.001 par value per share (“Shares”), of Radyne Corporation, a Delaware corporation (“Radyne”), at a price of $11.50 per Share, net to the seller in cash, without interest thereon and less any required withholding taxes, upon the terms and subject to the conditions set forth in the Offer.

Also enclosed is a letter to stockholders of Radyne from the President and Chief Executive Officer of Radyne, accompanied by Radyne’s Solicitation/Recommendation Statement on Schedule 14D-9.

We are the holder of record of Shares held by us for your account. A tender of such Shares can be made only by us as the holder of record and pursuant to your instructions. The Letter of Transmittal accompanying this letter is furnished to you for your information only and cannot be used by you to tender Shares held by us for your account.

We request instructions as to whether you wish to tender any or all of the Shares held by us for your account pursuant to the Offer.

1. The offer price is $11.50 per Share, net to the seller in cash, without interest thereon and less any required withholding taxes, upon the terms and subject to the conditions of the Offer.

3. The Offer is being made in connection with the Agreement and Plan of Merger, dated as of May 10, 2008 (together with any amendments or supplements thereto, the “Merger Agreement”), among Comtech, Purchaser and Radyne, pursuant to which, after the completion of the Offer and the satisfaction or waiver of certain conditions, Purchaser will be merged with and into Radyne, and Radyne will be the surviving corporation (the “Merger”). Capitalized terms used, but not defined, herein shall have the respective meanings given to them in the Merger Agreement.

4. The Radyne board of directors has, subject to the terms and conditions set forth in the Merger Agreement, unanimously (i) determined that the Merger Agreement and the transactions contemplated thereby, including each of the Offer and the Merger (collectively, the “Transactions”), are fair to, and in the best interests of, the holders of Shares, (ii) approved and declared advisable the Merger Agreement and the Transactions, and (iii) resolved to recommend that the holders of Shares accept the Offer and tender their Shares pursuant to the Offer, and that the holders of Shares adopt the Merger Agreement and approve the Transactions to the extent required by applicable Law.

5. The Offer is not subject to any financing condition, but is conditioned upon a number of other conditions as set forth in the Offer to Purchase. See Section 13 of the Offer to Purchase.

6. The initial offering period of the Offer and withdrawal rights will expire at the Expiration Date.

7. Any transfer taxes applicable to the sale of Shares to Purchaser pursuant to the Offer will be paid by Purchaser, except as otherwise provided in Instruction 6 of the Letter of Transmittal.

If you wish to have us tender any or all of the Shares held by us for your account, please so instruct us by completing, executing and returning to us in the enclosed envelope the attached instruction form. Please forward your instructions to us in ample time to permit us to submit a tender on your behalf prior to the Expiration Date. If you authorize the tender of your Shares, all such Shares will be tendered unless otherwise specified on the attached instruction form.

Payment for Shares will be in all cases made only after such Shares are accepted by Purchaser for payment pursuant to the Offer and the timely receipt by Computershare Trust Company, N.A., (the “Depositary”), of (a) certificates for such Shares or a Book-Entry Confirmation (as defined in the Offer to Purchase) with respect to such Shares, (b) a Letter of Transmittal (or facsimile thereof), properly completed and duly executed, with any required signature guarantees (or, in the case of a book-entry transfer, an Agent’s Message (as defined in the Offer to Purchase) in lieu of the Letter of Transmittal), and (c) any other documents required by the Letter of Transmittal. Accordingly, tendering stockholders may be paid at different times depending upon when certificates for Shares or Book-Entry Confirmations with respect to Shares are actually received by the Depositary. Under no circumstances will interest be paid on the purchase price for Shares, regardless of any extension of the Offer or any delay in payment for Shares.

The undersigned acknowledge(s) receipt of your letter and the enclosed Offer to Purchase, dated May 22, 2008 (as it may be amended or supplemented from time to time, the “Offer to Purchase”), and the related Letter of Transmittal (as it may be amended or supplemented from time to time, the “Letter of Transmittal” and, together with the Offer to Purchase, the “Offer”), in connection with the offer by Comtech TA Corp., a Delaware corporation (“Purchaser”) and a wholly-owned subsidiary of Comtech Telecommunications Corp., a Delaware corporation (“Comtech”), to purchase for cash all of the outstanding shares of common stock, $.001 par value per share (“Shares”), of Radyne Corporation, a Delaware corporation, at a price of $11.50 per Share, net to the seller in cash, without interest thereon and less any required withholding taxes, upon the terms and subject to the conditions set forth in the Offer.

This will instruct you to tender the number of Shares indicated on the reverse (or if no number is indicated on the reverse, all Shares) that are held by you for the account of the undersigned, upon the terms and subject to the conditions set forth in the Offer.

The undersigned understands and acknowledges that all questions as to validity, form and eligibility of the surrender of any certificate representing Shares submitted on my behalf to Computershare Trust Company, N.A., the Depositary for the Offer, will be determined by Purchaser (which may delegate power in whole or in part to the Depositary) and such determination shall be final and binding.

Number of Shares to Be Tendered: Shares*

Sign Below

Account Number: Signature(s):

Dated: , 2008

Please Type or Print Name(s) above

Please Type or Print Address(es) above

Area Code and Telephone Number

Taxpayer Identification or Social Security Number(s)

* Unless otherwise indicated, you are deemed to have instructed us to tender all Shares held by us for your account.

Please return this form to the brokerage firm or other nominee maintaining your account.