add a lower case l to the end of that http://www.midnightscience.com/ultrasonics.html GB & 73 K5OAI Sam Morgan On 12/21/2011 7:27 PM, Lee Ward wrote: > Phil, W0XI, has put a kit ultrasonic detector on the market. Well worth > looking into. > > http://www.midnightscience.com/ultrasonics.htm > > 73, Lee, K0LW