Hello friends and greetings from Barcelona, Catalonia, Spain, That's me again looking for help from you, the Elecrafter's community.
After having solved my recent "Info 80" trouble and since I had upgraded my KPA100 and all the F/W, my K2's configuration got quite disarranged, I decided to implement all the mods to upgrade my K2 rev A to a K2 rev B, before getting into the configuring and aligning task (I had installed some of the mods but not all) so I purchased the K2ATOBKT kit and did a lot of disoldering and soldering. All has run as per the manual but (Why there's always a but? Is it Murphy's Law?) now I have got a transmit power control problem. When I key down (TUNE) the K2 and independently of the value I set in the POWER Control (be it 0.50, 2.00, 5.00 or 10.00 watts) I always get the "Hi Cur" message and the internal wattmeter drops to 0.3 watts, but the truth is that the power transmitted into a very well calibrated 50 Ohm Dummy Load and RF Power Meter (the QRP RF-Power Meter PM-1300a by SSB-Electronics) always, and I mean always with independence of the K2 POWER Control, reads between 10-14 watts depending of the frequency. Have made the resistance checkings and they are OK My PS is a switched Daiwa SS-330 X with an output voltage of 13.8 v fixed and an output current continuous of 30 A Measuring the voltage at the K2 Aux 12v connector I get the following readings: K2 switched OFF = 13.84 v K2 switched ON = 13.62 v K2 transmitting = 13.16 v With the Cal Cur set at 2.5 A, on my DMM I get the following current readings: K2 receiving = 0.29 A K2 transmitting = 2.51 A The DC voltage readings for the PA finals Q7 and Q8 are: Collector K2 receiving = 13.60 v Collector K2 transmitting = 11.98 v Base K2 transmitting = 0.62 v DC voltage for the PA driver Q6 Collector K2 receiving = 13.60 v Collector K2 transmitting = 12.60 v Base K2 transmitting = 1.02 v Emitter K2 transmitting = 0.26 v I fear the PA finals may be damaged so they do not obey the POWER control settings, but am not convinced of that and although I have the K2PAKIT ready, I do not want to replace them unless it is necessary. BTW, the heat sink is isolated from the Q7 and Q8 collectors. Any ideas and/or suggestions will be much welcome. Sure I am missing something but honestly, at this moment, I do not know what. Look forward to hearing from you. Thanks in advance. Best 73 Pauli, EA3BLQ K2/100 # 1044 ea3blq(at)menta.net ea3blq(at)qsl.net URL: www.qsl.net/ea3blq _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
