EXHIBIT 10.17

                       FOURTH AMENDMENT TO LOAN AGREEMENT

     THIS FOURTH AMENDMENT TO LOAN AGREEMENT (the "Fourth  Amendment"),  is made
and entered into this 30 day of July, 2009, by and among HERLEY INDUSTRIES, INC.
(the "Borrower"), MANUFACTURERS AND TRADERS TRUST COMPANY and PNC BANK, NATIONAL
ASSOCIATION, successor to Bank of Lancaster County, a division of BLC Bank N.A.,
successor to Bank of Lancaster  County,  N.A. (each a "Lender" and collectively,
the "Lenders") and  MANUFACTURERS  AND TRADERS TRUST COMPANY,  as agent (in such
capacity, the "Agent").

                               B A C K G R O U N D

     A.  Borrower  has  borrowed  from Lenders and desires to continue to borrow
from Lenders in connection with the operation of its business(es).  On April 30,
2007,  the parties  entered into a Loan  Agreement,  upon which monies have been
advanced, which was amended by an Amendment to Loan Agreement dated May 2, 2008,
a Second  Amendment  to Loan  Agreement  dated  September  11,  2008 and a Third
Amendment  to  Loan  Agreement  dated  May  4,  2009  (as  amended,   the  "Loan
Agreement").  The Loan Agreement is incorporated  herein by reference and made a
part hereof.  All  capitalized  terms used herein without  definition  which are
defined in the Loan Agreement shall have the meanings set forth therein.

     B. Borrower has requested  Lenders to amend certain  provisions of the Loan
Agreement.

     C. The parties  desire to enter into this Fourth  Amendment  to  effectuate
such amendments.

     D. Borrower has no defense,  charge,  defalcation,  claim,  plea, demand or
set-off against the Loan Agreement or any of the Loan Documents.

     NOW,  THEREFORE,  for  valuable  consideration,  receipt of which is hereby
acknowledged,  and  intending to be legally  bound  hereby,  the parties  hereto
covenant and agree as follows:

     1. That the above Background is incorporated herein by reference.

     2. That the  definition  of "Debt  Service  Coverage  Ratio"  contained  in
Section 1.1 of the Loan  Agreement be and hereby is modified,  effective for the
fiscal  quarter  ending  August 2, 2009,  to exclude  from the rolling  four (4)
quarter calculation a $10,000,000.00  provision for employment settlement costs.
This modification  will reduce and eventually  terminate as the charge rolls out
of the calculation.

     3. That the Borrower shall pay to the Agent for the ratable  benefit of the
Lenders a  modification  fee in the amount of $20,000.00  upon execution of this
Fourth Amendment.

     4.  That the  Borrower  reaffirms  and  restates  the  representations  and
warranties  set forth in  Section 7 of the Loan  Agreement,  as  amended by this
Fourth Amendment,  and all such representations and warranties shall be true and
correct  on the date  hereof  with the same  force and effect as if made on such
date, except as they may specifically refer to an earlier date(s).  The Borrower
represents and warrants (which  representations and warranties shall survive the
execution and delivery hereof) to the Agent and the Lenders that (i) this Fourth
Amendment has been duly  authorized,  executed and  delivered  and  constitute a
legal,  valid and binding  obligation of the  Borrower,  and is  enforceable  in
accordance  with its terms;  (ii) the Borrower is not in default  under the Loan

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Agreement  or any of the  other  Loan  Documents,  and the  Borrower  is in full
compliance with all of the terms and conditions thereof;  (iii) no event exists,
or is likely to exist in the future,  which with the passage of time, notice, or
both,  will  constitute a default  under the Loan  Agreement or any of the other
Loan  Documents;  and (iv) there have been no  material  adverse  changes in the
Borrower's  financial  condition or operations which would cause the Borrower to
be in  default  under  any of the  financial  covenants  contained  in the  Loan
Documents.

     5.  That the terms  and  conditions,  paragraph  sections,  collateral  and
guaranty requirements,  representations and warranties of the Loan Agreement and
Loan Documents,  together with all  understandings by and between the parties to
this Fourth  Amendment  evidenced by writings of the same or subsequent date not
in  conflict  with the above  modifications  under this Fourth  Amendment  shall
remain in full force and effect as the agreement of the parties  relative to the
Loans, and are hereby ratified,  reaffirmed and confirmed.  Any past, present or
future delay or failure of the Agent and the Lenders to demand or enforce strict
performance of each term and condition of the Loan Agreement and Loan Documents,
and any past,  present or future delay or failure of the Agent or the Lenders to
exercise  any right,  power or  privilege  shall not be deemed or construed as a
waiver with  respect to the same or any other  matter,  or  preclude  the future
exercise of such right,  power or  privilege,  or be construed or deemed to be a
waiver of or acquiescence in any such default.

     6. That all  references to the Loan  Agreement,  the Loan Documents and the
other  documents  and  instruments   delivered  pursuant  to  or  in  connection
therewith, as well as in writings of the same or subsequent date, shall mean the
Loan  Agreement  as amended  hereby  and as each may in the  future be  amended,
restated, supplemented or modified from time to time. Further, all references to
Bank of Lancaster County, N.A. in the Loan Agreement, the Loan Documents and the
other documents and instruments delivered pursuant to or in connection therewith
shall  now be  deemed  to have  been  made and to refer  to PNC  Bank,  National
Association,  successor  to Bank of  Lancaster  County,  a division of BLC Bank,
N.A., successor to Bank of Lancaster County, N.A.

     7.  That the  parties  hereto  shall,  at any  time,  and from time to time
following the execution of this Fourth  Amendment,  execute and deliver all such
further  instruments  and take  all such  further  action  as may be  reasonably
necessary or  appropriate  in order to carry out the  provisions  of this Fourth
Amendment.

     IN WITNESS WHEREOF, and intending to be legally bound hereby, the Borrower,
the Lenders and the Agent have  caused this Fourth  Amendment  to be executed by
their proper corporate officers thereunto duly authorized as of the day and year
first above written.


ATTEST/WITNESS:                        HERLEY INDUSTRIES, INC.

/a/ Margaret Guzzetti                  By: Anello Garefino
                                       -----------------------------------------

Title:                                 Title: Chief Financial Officer
---------------------------------      -----------------------------------------
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                                       MANUFACTURERS AND TRADERS
                                       TRUST COMPANY, in its capacities as
                                       Agent and Lender


                                       By:  /s/ Jane E. McMinn
                                       -----------------------------------------
                                       Jane E. McMinn, Vice President


                                       PNC BANK, NATIONAL ASSOCIATION


                                       By:  Craig Kauffman
                                       -----------------------------------------


                                       Title:  SVP
                                       -----------------------------------------