This video shows the unique key-up characteristics of two different hand-held radios. The radios are a pair of multi-band HTs that are designed for the amateur/ham radio market. One is a Yaesu FT-470 Dual-Band (2m/440MHz), and the other is a Kenwood TH-F6A Tri-Bander (2m/220/440). The key-up, or transmitter turn-on characteristics are captured and analyzed on a real-time spectrum analyzer (Tektronix RSA5106A). It's quite surprising to see how differently these two transmitters behave, and how the transient characteristics of the transmitter turning on create very unique signatures that would make identification of these devices very easy simply by capturing their output over the air.