Jim Dunstan wrote: > The KX3 specifications indicate a nominal 10 watts output. When > operating a mode such as PSK, which presents a continuous output, > what is the recommended power output?
We recommend using 5 W for data modes and keeping transmissions reasonably short. However, you can definitely use full power (up to 12 W) if the duty cycle is low, such as during hunt-and-pounce in a contest. Of course as the duty cycle goes up, so will the PA and case temperature, and eventually the KX3 may automatically roll back your power output. I just did a test using the built-in PSK-D mode, alternately transmitting and receiving for 20 seconds each (simulating short contest contacts). At 12 watts (20 meters), the temperature never got high enough to roll back power during ten minutes of this. I then tested the KX3's high-efficiency TX mode, which reduces current drain by roughly 50% for a given power level. This mode kicks in at at 5.0 W or less in CW/FSK-D modes, and at 3.0 W or less in all other modes. So I set power to 3.0 W in PSK-D mode, which is amazingly effective given the S/N ratio of PSK31, and transmitted continuously. After 5 minutes the PA temperature was still increasing slowly, but I'm guessing I could have gone on for another 5-10 minutes. The lesson, here, is to let the other station transmit once in awhile :) Wayne N6KR ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
