SECURITIES AND EXCHANGE COMMISSION

                             Washington, D.C. 20549


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                         AMENDMENT NO. 1 ON FORM 8-K/A

                                 CURRENT REPORT



                       Pursuant to Section 13 or 15(d) of
                      the Securities Exchange Act of 1934

                                 Date of Report
                       (Date of earliest event reported):

                                 July 30, 1997


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                            THERMO OPTEK CORPORATION
             (Exact name of Registrant as specified in its charter)

       Delaware                 1-11757                  04-3283973
       (State or other        (Commission           (I.R.S. Employer
       jurisdiction of        File Number)        Identification Number)
       incorporation or
       organization)


       8E Forge Parkway
       Franklin, Massachusetts                                02038
       (Address of principal executive offices)               (Zip Code)



                                 (617) 622-1000
                         (Registrant's telephone number
                              including area code)
PAGE






       Item 7.   Financial Statements, Pro Forma Combined Condensed
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                 Financial Information and Exhibits
                 ----------------------------------

                 (a)  Financial Statements of Business Acquired: Not 
                      applicable.

                 (b)  Pro Forma Combined Condensed Financial 
                      Information: Not applicable.

                 (c)  Exhibits

                      2.   Share Purchase Agreement dated as of July 30,
                           1997, between Thermo Optek Corporation and
                           Thermo Instrument Systems Inc. (incorporated
                           by reference herein from Exhibit 2 to the
                           Company's Quarterly Report on Form 10-Q for
                           the Quarter ended June 28, 1997).


                                   SIGNATURES

            Pursuant to the requirements of the Securities Exchange Act
       of 1934, the Registrant has duly caused this report to be signed
       on its behalf by the undersigned thereunto duly authorized, on
       this 10th day of October, 1997.

                                          THERMO OPTEK CORPORATION


                                          By: /s/ Melissa F. Riordan
                                              ----------------------
                                               Melissa F. Riordan
                                               Treasurer