I completed my K1 assembly/alignment/testing after about 27 hours. A couple of those hours were spent dealing with the periodic noise burst on RX.
I'm happy to report, that with the addition of a couple of 0.47uF caps on the 6A and 6B power supply rails, the periodic noise burst signal level was substantially reduced. I can still hear it faintly on a dummy load, but on air tests show the signal is below the atmospheric noise level on 20/30 meters. Also, it no longer "colors" the RX signals, not even weak ones. My final conclusion is that there was a stability issue with the 78L06 regulators due to the placement of bulk and bypass caps. That nose was the most significant issue I had with the radio. The other had to do with the wrong size toroids being supplied for the Filter Board. After adjusting the turn count for the size difference, I went ahead and used the cores, but found that the 30 meter TX power wouldn't go above 3 watts. Winding correct size cores fixed that problem. Another minor nit came up once the metal covers were all installed. That caused a shift of about 150 Hz in the TX offset frequency. In addition, the built in power meter, which was surprisingly accurate with the bottom and top cover off, is now a couple of watts off. It reads 7 watts, when it is actually putting out 5 watts. Both of these issues are a result of de-tuning when the covers are on. Pull the covers off and things are back to where they were originally. All in all, I'm very happy. The RX performance is quite good, and even the audio derived AGC is doing an acceptable job. It was fun to put together. Thanks for a great kit, Elecraft. 73, Bob, WB4SON ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
