This is sorta like reading how to build a watch to find out the time. Bottom line. Keyer sets the mode. Paddle can be single or double depending on personal preferences. I use both. That's what time it is. 73, Jim Jim Larsen, AL7FS Anchorage, Alaska http://www.qsl.net/al7fs Anchorage Amateur Radio Club: http://www.KL7AA.org