Exhibit 4.1
                                                       -----------      

                                 PROMISSORY NOTE
                                UNSECURED DEMAND



$  20,000.00                                                October 30, 1996
- ------------                                                ----------------


For value received,  Sono-Tek  Corporation (the "Borrower"),  hereby promises to
pay to the order of James L. Kehoe (the  "Lender")  Twenty  thousand  dollars ON
DEMAND.

The Borrower  agrees to pay interest from the date hereof on the unpaid  balance
of this note, at a rate per annum equal to 10.25%.  Interest shall be calculated
on the basis of a 360 day year.

The Borrower  agrees to pay all costs and expenses,  such as wire transfer fees,
bank fees or broker charges, incurred by Lender to effect this loan.





Borrower:   Sono-Tek Corporation
            2012 Rt. 9W Bldg. 3
            Milton, NY 12547




Signature   /s/ Harvey L. Berger      President
            --------------------           
            Harvey L. Berger





Signature   /s/ J. Duncan Urquhart    Controller & Treasurer
            ----------------------
            J. Duncan Urquhart