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                                                                   EXHIBIT 10.11


              FOURTH AMENDMENT TO REVOLVING CREDIT LOAN AGREEMENT



This AMENDMENT, dated the 26th day of June, 1998 between SymmetriCom, INC., a
California corporation, (herein referred to as the "Borrower") and COMERICA
BANK-California (herein referred to as the "Bank").

                                  WITNESSETH:

WHEREAS, the Bank and the Borrower on December 1, 1993 entered into a certain
Revolving Credit Loan Agreement (the "Agreement"), a certain Revolving Credit
Master Note (the "Revolving Credit Note"), a certain Guaranty, a certain
Corporate Resolution Authorizing Execution of Guaranty, a certain Loan
Disbursement Order, and a certain Advance & Repayment Agreement (collectively
the "Loan Documents"); and

WHEREAS, the Borrower desires to borrow up to Seven Million and 00/100 Dollars
($7,000,000.00) from the Bank from time to time for the working capital needs of
the Borrower; and

WHEREAS, the modifications to the Agreement and to the Revolving Credit Note
contemplated hereby are in the best interest of, and will mutually benefit, the
parties hereto; and

NOW, THEREFORE, in consideration of the premises and the mutual promises herein
contained, the Borrower and the Bank agree to amend the Agreement in the manner
and to the extent hereinafter set forth:

1.   Replace Section 6.5 with the following: "Maintain Tangible Net Worth. On a
consolidated basis, maintain a Tangible Net Worth of not less than the amount
specified during the period specified below:

          (a) $75,000,000 from the date of this Amendment and to increase on
June 30, 1999 by 70% of Borrower's fiscal 1998 net profit after tax.

2.   Replace Section 6.8 with the following: "Maintain Profitability. On a
consolidated basis, for the fiscal quarter ending March 31, 1999, maintain Net
Income greater than ZERO DOLLARS ($0). After the fiscal quarter ending March 31,
1999, Borrower shall maintain Net Income greater than zero dollars ($0) at least
every second quarter.

IN WITNESS WHEREOF, the parties hereto have caused this Fourth Amendment to the
Agreement and the Revolving Credit Note to be executed and delivered by their
duly authorized officers on the day and year first written above.
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By:  /s/ ROGER A. STRAUCH                       By:   /s/ THOMAS W. STEIPP    
--------------------------                      --------------------------    
     Roger A. Strauch                                 Thomas W. Steipp
                                                Its:  President and COO,      
Its: Chief Executive Officer                          Telecom Solutions       
                                                                              
                                                                              
                                                COMERICA BANK-CALIFORNIA      
                                                                              
                                                                              
                                                By:  /s/ MARK HILLHOUSE       
                                                --------------------------    
                                                     Mark Hillhouse           
                                                Its: Corporate Banking Officer