This is an old thread, but is something that I have struggled with on my own K2. I also had some RF feedback that was mixed with this, but I have cured that.
So now I am left with the very similar symptoms where there are too many ALC lights lit for 40m and it overdrives my KPA500. I had to play with SSBA, which I would set to 1 on 40m and 2 on 20m. But even with SSBA set to 1 I get much to much power on 40m for the amplifier. I am using the MH2 mic. I went through the checks. I have the new PA. There are only 1-2 ALC bars lit on 20m and 15m. There are typically 7 lit on 40m. With SSBA set to 1 the voltage at KSB2 U1 pin 10 was not near zero. It was 2.5V. I checked the values and soldering of R14 and R15 and all looked ok. As were the other components listed. Thinking that the incorrect voltage means that I should change the component values I updated R9 to 15k and added a 1k between the base of Q1 and P1 pin 6. The voltage is now near zero, but it has not improved things. I still need to use SSBA 2 for 20m otherwise the drive is low. But SSBA 1 on 40m has too much drive. As soon as the KPA100 clicks in (as I turn from 10-11Watts) the amp is over driven. Any suggestions? 73 Chris ac2cz / g0kla -- Sent from: http://elecraft.365791.n2.nabble.com/ ______________________________________________________________ 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
