UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 1)* ESCO Electronics Corporation ----------------------------------------------------------------- (Name of Issuer) Common Stock Trust Receipts ----------------------------------------------------------------- (Title of Class of Securities) 269030201 ---------------------------------- (CUSIP Number) *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). SEC 1745 (2/92) Page 1 of 5 pagesCUSIP No. 269030201 13G Page 2 of 5 Pages 1 NAME OF REPORTING PERSON S.S. or I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Avenir Corporation IRS ID No.: 54-1146619 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) /__/ (b) /X/ 3 SEC USE ONLY 4 CITIZENSHIP OR PLACE OF ORGANIZATION State of Virginia, United States 5 SOLE VOTING POWER NUMBER OF 674,700 SHARES 6 SHARED VOTING POWER 0 BENEFICIALLY OWNED BY 7 SOLE DISPOSITIVE POWER 674,700 EACH REPORTING PERSON 8 SHARED DISPOSITIVE POWER 0 WITH 9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 674,700 10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* N/A 11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9 5.76% 12 TYPE OF REPORTING PERSON* IA SEC 1745 (2/92) CUSIP No. 269030201 13G Page 3 of 5 Pages Item 1. (a) Name of Issuer ESCO Electronics Corporation (b) Address of Issuer's Principal Executive Offices 888 Ladue Road, Ste 200, St. Louis, MO 63124 Item 2. (a) Name of Person Filing Avenir Corporation (b) Address of Principal Business Office or, if none, Residence 1725 K Street, NW Ste 410 Washington, D.C. 20006 (c) Citizenship State of Virginia (d) Title of Class of Securities Common Stock Trust Receipts (e) CUSIP Number 269030201 Item 3. If this statement is filed pursuant to Rule 13d-1(b), or 13d-2(b), check whether the person filing is a: (a) /__/ Broker or Dealer registered under Section 15 of the Act (b) /__/ Bank as defined in section 3(a)(6) of the Act (c) /__/ Insurance Company as defined in section 3(a)(19) of the act (d) /__/ Investment Company registered under section 8 of the Investment Company Act (e) /X_/ Investment Adviser registered under section 203 of the Investment Advisers Act of 1940 (f) /__/ Employee Benefit Plan, Pension Fund which is subject to the provisions of the Employee Retirement Income Security Act of 1974 or Endowment Fund; see 240.13d-l(b)(l)(ii)(F) (g) /__/ Parent Holding Company, in accordance with 240.13d-l(b)(ii)(G) (Note: See Item 7) SEC 1745 (2/92) CUSIP No. 269030201 13G Page 4 of 5 Pages (h) /__/ Group, in accordance with 240.13d-l(b)(l)(ii)(H) Item 4. Ownership If the percent of the class owned, as of December 31 of the year covered by the statement, or as of the last day of any month described in Rule 13d-l(b)(2), if applicable, exceeds five percent, provide the following information as of that date and identify those shares which there is a right to acquire. (a) Amount Beneficially Owned 674,700 (b) Percent of Class 5.76% (c) Number of shares as to which such person has: (i) sole power to vote or to direct the vote 674,700 (ii) shared power to vote or to direct the vote 0 (iii) sole power to dispose or to direct the dispostion of 674,700 (iv) shared power to dispose or to direct the disposition of 0 Item 5. Ownership of Five Percent or Less of a Class Not Applicable Item 6. Ownership of More than Five Percent on Behalf of Another Person. Not Applicable Item 7. Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on By the Parent Holding Company Not Applicable Item 8. Identification and Classification of Members of the Group Not Applicable Item 9. Notice of Dissolution of Group Not Applicable SEC 1745 (2/92) CUSIP No. 269030201 13G Page 5 of 5 Pages 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. 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. April 28, 1997 Avenir Corporation By: /s/ Charles G. Mackall, Jr. ---------------------------- Charles G. Mackall, Jr. President SEC 1745 (2/92)