The Ameritron AL-80B has a dynamic bias circuit to cut off the idle current and reduce heat. It also introduces SSB distortion. The heat reduction is minimal. This circuit can be disabled and distortion removed by connecting a 10 K ohm resistor from the base of Q1 to the collector of Q1 as shown in the attached picture. The 10 K resistor causes Q1 to turn on all the time, fooling the amplifier into thinking there is continuous RF input to the amplifier. With this modification, the AL-80B works great on SSB with low distortion. SEE PICTURE HERE 73 de K5GP, Gene, k5gp@arrl.net see shack and sailboat: http://qrz.com/callsign.html?callsign=k5gp digital: SCS PTC-IIe, Win98, Airmail 2.8, Knwd TS-570, Yaesu FT-100 other: Ameritron AL-80B, Cushcraft R7000 vertical, Dell 450 MHz PC