Good morning Elecrafters! My K2 power output problem solved, first QSO done. Everything seems to be OK now.
Yesterday my friend Sami, OH4KLU, came over and we looked together into K2 problem. There was no indication of TX nowhere. 8R voltage went down to 0.6 V, not below 0.3 V. We started to look reason for that and didn't find any. Then checked D7 and voltage was missing from there when in TUNE. Then we looked for 8T and found out that U6 P27 on control board did not go to 5 V when in TUNE. P28 RX was OK and changed from 5 to 0 V when in TUNE. Then we look into Q1-Q4 (ctrl-board) and found that there was something wrong around Q3. There was only 100 ohms between gate and ground. We took another 2N7000 from amp keying kit and replaced Q3. Then tested again and got 1+ watts from 40 m. TX worked! I installed heat sink back in place and started to align BPF. All bands went easily to 2 watts and got 10 watts in 40 m with 2.2 A using 12 V SLA-battery as power supply. It was late after midnight, so we didn't test other bands power output. But we had to make short test and put a wire on the balcony and went looking for stations in 40 m. With 5 watts I worked HF650D (SP) and asked about my tone. The answer was that tone is FB and clear. Then I shut down K2 and went to sleep with big smile on my face. Today I will check output on other bands too and go to test the rig with better antennas. Thank you Gary at Elecraft, Don W3FPR and others for help. I still have many options to go ahead, so I believe I will need some assistance later on too. 73 de Jukka, OH4MFA K2 #4293 p.s. I found PTTL in T6 :( I will make toroids in the future more carefully. _______________________________________________________________________ Parhaat hakupalvelut yhdessä osoitteessa: http://www.eniro.fi/ Suomalaisten yritysten tuotteet ja palvelut: http://yritykset.eniro.fi/ _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net http://mailman.qth.net/mailman/listinfo/elecraft You must subscribe to post. Subscriber Info (Addr. Change, Unsub etc): http://mailman.qth.net/subscribers.htm Elecraft page: http://www.elecraft.com
