1 EXHIBIT 10.51 		SIXTH AMENDMENT TO CREDIT AGREEMENT AND NOTE 	THIS SIXTH AMENDMENT TO CREDIT AGREEMENT AND NOTE ("Sixth Amendment"), made and entered into as of the 3rd day of January, 1996 by and between DATRON SYSTEMS INCORPORATED, a Delaware corporation ("Company"), and UNION BANK, a California banking corporation ("Bank"), 				W I T N E S S E T H: 	WHEREAS, on May 11, 1994, the Company and the Bank entered into a certain Credit Agreement and Note (as amended by those certain First, Second, Third, Fourth and Fifth Amendments to Credit Agreement and Note, dated as of October 26, 1994, December 29, 1994, February 28, 1995, March 31, 1995 and August 17, 1995, respectively, the "Credit Agreement") pursuant to which the Bank agreed to extend to the Company and the Company agreed to accept from the Bank certain credit facilities more particularly described therein; and 	WHEREAS, the Company and the Bank desire to amend the Credit Agreement to provide for a temporary Two Million Dollar ($2,000,000.00) increase in availability under the Revolving Loan Facility, and a temporary aggregate Two Million Dollar ($2,000,000.00) decrease in availability under the Standby Facility and the L/C Facility, during the period commencing on the Sixth Amendment Effective Date (as hereinafter defined) and ending on January 31, 1996; 	NOW, THEREFORE, for and in consideration of the premises hereof, and other good and valuable consideration the receipt and adequacy of which are hereby acknowledged, the parties hereto hereby agree as follows: 	1. All capitalized terms used in this Sixth Amendment, shall unless otherwise defined herein or unless the context otherwise requires have the meanings given thereto in the Credit Agreement. 	2. Subsection 1.01(a) of the Credit Agreement is amended to read as follows: 		(a) The outstanding principal amount of all Revolving 	Loans shall not exceed in the aggregate (i) at any given 	time during the period commencing on the Sixth Amendment 	Effective Date and ending on January 31, 1996, Ten Million 	Five Hundred Thirty-five Thousand Dollars ($10,535,000.00), 	or (ii) at any other given time, Eight Million Five Hundred 	Thirty-five Thousand Dollars ($8,535,000.00) (the "Revolving 	Loan Commitment"); 2 	3. Subsection 1.01(b) of the Credit Agreement is amended to read as follows: 		(b) Except as otherwise provided in Subsections 	1.01(c),(d) and (e) hereof, the sum of: 			(i) the aggregate amount available to be 		drawn under all Standby L/C's; 			(ii) the aggregate amount of unpaid 		reimbursement obligations in respect of all drafts 		drawn under Standby L/C's (the sum of the aggregate 		amounts described in Subsection 1.01(b)(i) hereof 		and in this Subsection 1.01(b)(ii) being hereinafter 		referred to as "Standby L/C Utilization"); 			(iii) the aggregate amount available to be drawn under all Commercial L/C's; and 			(iv) the aggregate amount of unpaid 		reimbursement obligations in respect of all drafts 		drawn under Commercial L/C's (the sum of the aggregate 		amounts described in Subsection 1.0(b)(iii) hereof and 		in this Subsection 1.01(b)(iv) being hereinafter 		referred to as "Commercial L/C Utilization"); 	shall not exceed (x) at any given time during the period 	commencing on the Sixth Amendment Effective Date and ending 	on January 31, 1996, Sixteen Million Dollars 	($16,000,000.00), or (y) at any other given time, Eighteen 	Million Dollars ($18,000,000.00); 	4. Subsection 1.01(c) of the Credit Agreement is amended to read as follows: 		(c) Commercial L/C Utilization shall not exceed 	in the aggregate at any one time the lesser of: 		(i) Two Million Dollars ($2,000,000.00); or 		(ii) the difference between: 			(A) at any given time during the period 			commencing on the Sixth Amendment Effective 			Date and ending on January 31, 1996, Sixteen 			Million Dollars ($16,000,000.00) or, at any 			given time, Eighteen Million Dollars 			($18,000,000.00); and 			(B) Standby L/C Utilization; 3 	5. Subsection l.01(e) of the Credit Agreement is amended to read as follows: 		(e) Standby L/C Utilization relating to Standby L/C's 	issued in favor of beneficiaries located in countries listed 	in Column D of Exhibit A hereto (individually a "Column D 	Country" and collectively the "Column D Countries") shall 	not exceed in the aggregate at any one time: 		(i) in the case of all beneficiaries located in any 		given Column D Country, Five Hundred Thousand Dollars 		($500,000.00); and 		(ii) in the case of all beneficiaries located in all 		Column D Countries, the lesser of: 			(A) Two Million Five Hundred Thousand Dollars 			($2,500,000.00); or 			(B) the difference between: 				(1) at any given time during the period 				commencing on the Sixth Amendment Effective 				Date and ending on January 31, 1996, 				Sixteen Million Dollars ($16,000,000.00) 				or, at any other given time, Eighteen 				Million Dollars ($18,000,000.00); and 				(2) the sum of (I) Standby L/C 				Utilization relating to Standby L/C's 				issued in favor of all beneficiaries 				located in all countries other than 				Column D Countries, and (II) Commercial 				L/C Utilization. 	6. Section 7.01 of the Credit Agreement is amended by the addition thereto of the following definitions in proper alphabetic order: 	"Sixth Amendment" shall mean that certain Sixth Amendment to 	Credit Agreement and Note, dated as of January 3, 1996, by 	and between the Company and the Bank. 	"Sixth Amendment Effective Date" shall mean the date on which 	the Sixth Amendment becomes effective as provided in 	Paragraph 7 thereof. 	7. This Sixth Amendment shall become effective on the date on which the Bank receives this Sixth Amendment, duly executed by the Company. 4 	8. Except as expressly provided herein, the Credit Agreement is unchanged and remains in full force and effect. 	9. This Sixth Amendment shall be governed by and construed in accordance with the laws of the State of California. 	10. This Sixth Amendment may be executed in any number of identical counterparts, any set of which signed by both parties hereto shall be deemed to constitute a complete, executed original for all purposes. 	IN WITNESS WHEREOF, the Bank and the Company have caused this Sixth Amendment to be executed as of the day and year first above written. UNION BANK DATRON SYSTEMS INCORPORATED By: /s/ RICHARD A. PETRIE By: /s/ WILLIAM L. STEPHAN Title: Vice President Title: Vice President By: /s/ M. E. CONBOY By: /s/ DAVID A. DERBY Title: Vice President Title: President and CEO