A K3/P3 can be used to measure the KX3 SSB TX bandpass. The process is to speak random words for several seconds while monitoring with a P3 in "Peak" mode. After about 30 seconds the display will stabilize. The K3 filter width is 2.1 KHz 350 - 2450 Here are some measurements: http://kn5l.net/KX3-TxEq/ John KN5L