OMB APPROVAL OMB NUMBER: 3235-0145 EXPIRES: DECEMBER 31, 1997 ESTIMATED AVERAGE BURDEN HOURS PER RESPONSE . . . . 14.90 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* Mercury Computer Systems, Inc. - ------------------------------------------------------------------------------- (Name of Issuer) Common Stock - ------------------------------------------------------------------------------- (Title of Class of Securities) 589378108 ------------------------------- (CUSIP Number) Check the following box if a fee is being paid with this statement [ ]. (A fee is not required only if the filing person: (1) has a previous statement on file reporting beneficial ownership of more than five percent of the class of securities described in Item 1; and (2) has filed no amendment subsequent thereto reporting beneficial ownership of five percent or less of such class.) (See Rule 13d-7). *The remainder of this cover page shall be filled out for a reporting person's initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page. The information required in the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes). CONFORMED COPY TO FILING MADE ON FEBRUARY 5, 1999
CUSIP NO. 589378108 PAGE _____ OF____ PAGES 13G - ------------------------------------------------------------------------------- 1 NAME OF REPORTING PERSON S.S. or I.R.S. IDENTIFICATION NO. OF ABOVE PERSON PETER B. CANNELL & CO., INC. 13-3346990 - ------------------------------------------------------------------------------- 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) [ ] (b) [ ] - ------------------------------------------------------------------------------- 3 SEC USE ONLY - ------------------------------------------------------------------------------- 4 CITIZENSHIP OR PLACE OF ORGANIZATION DELAWARE - ------------------------------------------------------------------------------- 5 SOLE VOTING POWER NUMBER OF 694,475 SHARES ------------------------------------------------------ BENEFICIALLY 6 SHARED VOTING POWER OWNED BY EACH REPORTING ------------------------------------------------------ PERSON WITH 7 SOLE DISPOSITIVE POWER 694,475 ------------------------------------------------------ 8 SHARED DISPOSITIVE POWER - ------------------------------------------------------------------------------- 9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 694,475 WHICH CONSISTS SOLELY OF COMMON STOCK - ------------------------------------------------------------------------------- 10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* - ------------------------------------------------------------------------------- 11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9 6.93% - ------------------------------------------------------------------------------- 12 TYPE OF REPORTING PERSON* IA - ------------------------------------------------------------------------------- *SEE INSTRUCTION BEFORE FILLING OUT!
Item 1(a). Name of Issuer: Mercury Computer Systems, Inc. Item 1(b). Address of Issuer's Principal Executive Offices: 199 Riverneck Road Chelmsford, MA 01824 Item 2(a). Name of Person Filing: Peter B. Cannell & Co., Inc. Item 2(b). Address of Principal Business Office: 645 Madison Avenue, New York, NY 10022 Item 2(c). Citizenship: Delaware Corporation Item 2(d). Title of Class of Securities: Common Stock Item 2(e). CUSIP No. 589378108 Item 3. Person filing statement is: (e)[X] Investment Adviser registered under Section 203 of the Investment Advisers Act of 1940. Item 4. Ownership: (a) Amount Beneficially Owned: 694,475 (b) Percent of Class: 6.93% (c) Number of shares as to which such person has sole power to dispose or to direct the disposition of: 694,475 Item 5. Ownership of Five Percent or less: N/A Item 6. Ownership of More than Five Percent: N/A
Item 7. Identification and Classification of the Subsidiary: N/A. Item 8. Identification and Classification of Members of Group: N/A. Item 9. Notice of Dissolution: N/A. Item 10. Certification.
By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired in the ordinary course of business and were not acquired for the purpose of and do not have the effect of changing or influencing the control of the issuer of such securities and were not acquired in connection with or as a participant in any transaction having such purposes or effect. SIGNATURE After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct. February 5, 1999 ------------------------------ (Date) Patricia Kogan ------------------------------ (Signature) Patricia Kogan, Vice President ------------------------------ (Name/Title)