Easy to use computer program for Windows allows you to design and test crystal radio circuits on your PC! It calculates Ohm's Law, resistor values, antenna designs, impedance for various R, L, C combinations, power, voltage, coil inductance, capacitance and more. It also shows 200 crystal radio circuits that you can build and experiment with, or you can design your own. Build a crystal set that drives a loudspeaker! From Mathstar. STOCK NO. D-402CD CD-ROM for IBM compatible computers. $29.95 SONORAN PUBLISHING - Email: snrnpub@aol.com PHONE (480) 961-5176 FAX (480) 961-5256