This appendix gives data for most of the components that are used in the NorCal 40A. We appreciate the manufacturers giving us permission to copy data sheets. Often data sheets have a great deal of information, but it is important to make your own measurements to check them. Manufacturers vary greatly in how conservatively they rate their devices. In addition, they may be testing the devices under conditions that are different from yours. Often several manufacturers sell a device with same part number, and the performance between different manufacturers varies. These data sheets are no substitute for the data books and Web sites that give the complete list of products that a manufacturer sells. Many of these devices are part of a wide line of products that will cover a range of frequencies, functions, and power levels. For much more component information, see Data Book for Homebrewers and QRPers, by Paul Harden, published by Quicksilver Printing. The book is available from Five Watt Press, 740 Galena Street, Aurora, CO 80010-3922, email:qrpbook@aol.com.