Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
ZEFF DANIEL
  2. Issuer Name and Ticker or Trading Symbol
ELECTRO SENSORS INC [ELSE]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director __X__ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
(Last)
(First)
(Middle)
50 CALIFORNIA STREET, SUITE 1500
3. Date of Earliest Transaction (Month/Day/Year)
04/25/2006
(Street)

SAN FRANCISCO, CA 94111
4. If Amendment, Date Original Filed(Month/Day/Year)
6. Individual or Joint/Group Filing(Check Applicable Line)
___ Form filed by One Reporting Person
_X_ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)
2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)
4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)
5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)
6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)
7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Common Stock (1) 04/25/2006   P   374 (2) D $ 6.18 179,734 I See Footnote (2)
Common Stock (1) 04/25/2006   P   559 (2) D $ 6.19 179,175 I See Footnote (2)
Common Stock (1) 04/25/2006   P   2,777 (2) D $ 6.2 176,398 I See Footnote (2)
Common Stock (1) 04/25/2006   P   683 (2) D $ 6.21 175,715 I See Footnote (2)
Common Stock (1) 04/25/2006   P   47 (2) D $ 6.24 175,668 I See Footnote (2)
Common Stock (1) 04/25/2006   P   514 (2) D $ 6.25 175,154 I See Footnote (2)
Common Stock (1) 04/25/2006   P   980 (2) D $ 6.26 174,174 I See Footnote (2)
Common Stock (1) 04/25/2006   P   94 (2) D $ 6.27 174,080 I See Footnote (2)
Common Stock (1) 04/25/2006   P   4,733 (2) D $ 6.28 169,347 I See Footnote (2)
Common Stock (1) 04/25/2006   P   1,903 (2) D $ 6.3 167,444 I See Footnote (2)
Common Stock (1) 04/25/2006   P   94 (2) D $ 6.31 167,350 I See Footnote (2)
Common Stock (1) 04/25/2006   P   326 (2) D $ 6.34 167,024 I See Footnote (2)
Common Stock (1) 04/25/2006   P   4,941 (2) D $ 6.35 162,083 I See Footnote (2)
Common Stock (1) 04/25/2006   P   560 (2) D $ 6.36 161,523 I See Footnote (2)
Common Stock (1) 04/25/2006   P   47 (2) D $ 6.38 161,476 I See Footnote (2)
Common Stock (1) 04/25/2006   P   2,522 (2) D $ 6.4 158,954 I See Footnote (2)
Common Stock (1) 04/25/2006   P   327 (2) D $ 6.43 158,627 I See Footnote (2)
Common Stock (1) 04/25/2006   P   560 (2) D $ 6.45 158,067 I See Footnote (2)
Common Stock (1) 04/25/2006   P   419 (2) D $ 6.46 157,648 I See Footnote (2)
Common Stock (1) 04/25/2006   P   1,516 (2) D $ 6.5 156,132 I See Footnote (2)
Common Stock (1) 04/25/2006   P   1,818 (2) D $ 6.51 154,314 I See Footnote (2)
Common Stock (1) 04/25/2006   P   466 (2) D $ 6.52 153,848 I See Footnote (2)
Common Stock (1) 04/25/2006   P   745 (2) D $ 6.55 153,103 I See Footnote (2)
Common Stock (1) 04/25/2006   P   280 (2) D $ 6.56 152,823 I See Footnote (2)
Common Stock (1) 04/25/2006   P   47 (2) D $ 6.58 152,776 I See Footnote (2)
Common Stock (1) 04/25/2006   P   47 (2) D $ 6.59 152,729 I See Footnote (2)
Common Stock (1) 04/25/2006   P   1,657 (2) D $ 6.6 151,072 I See Footnote (2)
Common Stock (1) 04/25/2006   P   94 (2) D $ 6.61 150,978 I See Footnote (2)
Common Stock (1) 04/25/2006   P   94 (2) D $ 6.7 150,884 I See Footnote (2)
Common Stock (1) 04/25/2006   P   373 (2) D $ 6.74 150,511 I See Footnote (2)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)
2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)
5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)
6. Date Exercisable and Expiration Date
(Month/Day/Year)
7. Title and Amount of Underlying Securities
(Instr. 3 and 4)
8. Price of Derivative Security
(Instr. 5)
9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)
10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)
11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
ZEFF DANIEL
50 CALIFORNIA STREET
SUITE 1500
SAN FRANCISCO, CA 94111
    X    
Zeff Holding Company, LLC
50 CALIFORNIA STREET
SAN FRANCISCO, CA 94111
    X    
Zeff Capital Partners I, L.P.
C/O ZEFF HOLDING COMPANY, LLC
50 CALIFORNIA STREET
SAN FRANCISCO, CA 94111
    X    
Spectrum Galaxy Fund Ltd.
50 CALIFORNIA STREET
SUITE 1500
SAN FRANCISCO, CA 94111
    X    

Signatures

 Daniel Zeff   04/27/2006
**Signature of Reporting Person Date

 Daniel Zeff for Zeff Capital Partners I, L.P.   04/27/2006
**Signature of Reporting Person Date

 Dion R. Friedland for Spectrum Galaxy Fund Ltd.   04/27/2006
**Signature of Reporting Person Date

 Daniel Zeff for Zeff Holding Company, LLC   04/27/2006
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) This Form 4 is being filed by Daniel Zeff, Spectrum Galaxy Fund Ltd. ("Spectrum"), Zeff Capital Partners I, L.P. ("Capital") and Zeff Holding Company, LLC ("Holding").
(2) This transaction was effected through Capital. Mr. Zeff is the sole manager and member of Holding, which in turn serves as the general partner for Capital. In accordance with Instruction 4(b)(iv) of Form 4, the entire amount of the Issuer's securities held by Capital is reported herein. Each of Mr. Zeff and Holding disclaims, for purposes of Section 16 of the Securities Exchange Act of 1934, beneficial ownership of such securities, except to the extent of its/his indirect pecuniary interest therein, and this report shall not be deemed an admission that any of Mr. Zeff or Holding is the beneficial owner of such securities for purposes of Section 16 or for any other purposes. Spectrum disclaims beneficial ownership over all shares held through Capital.

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