Don: I sent the txt below a while back but it must have gotten lost in cyberspace. In addition to the measurements below, when I turn on the K2 now I get the full Elecraft in the LCD, a few clicks from relays and the speaker as well as a steady medium frequency tone. Nothing works on the pannel.
BEGIN EMAIL I disconnected everything and put it aside for a while. Now I am back to it. The measurements are as follows: Q1 Collector: 6.77 (Fluctuates, The first time I measured it was 7.6) Q2 Collector: 7.3 (Fluctuates) Q3 Gate: .003 Q4 Gate: 7.25 Shorted Q3? How would it have shorted. I do not see anything that would have caused the short. In addition, once this issue is sorted out, I would like to go through a complete tune up procedure. I have the following upgrades in the K2 along with the KAT/KPA 100 in a separate enclosure: K60XV (No longer shows up on the LCD), KIO2, K160RX, KNB2, KAT2, KSB2, KBT2 Is there a stem to stern check-up procedure that I can follow? As always, thanks for your assistance. Chris Amyes K7CJA Don Wilhelm-4 wrote: > > Chris, > > Keep that dummy load attached, and set the power knob to zero. That K2 > is going into transmit, so you want to protect the PA from harm while > figuring out what is going on. > > Remove anything that may be plugged into either the paddle jack or the > mic jack and try again. > If it still goes into transmit, remove the top cover and on the Control > Board, check the collector of Q1 - it will be between 7.5 and 8 volts if > the K2 is in transmit. Also, check the collector of Q2, which should be > at 7.5 to 8 volts during receive, If both Q1 and Q2 have voltage on the > collector, it is trying to transmit and receive at the same time, so > keep the power on intervals short if that condition is present. > > Assuming you have the 8 volts at the collector of Q1 but near zero at > the collector of Q2 (proper for transmit state), then check pins 29 and > 30 of Control Board U6 (the microprocessor) - both should be higher than > 4 volts (close to 5 volts). If one or both are at a low voltage, there > is something holding the dot or dash lines low, and you should be able > to locate it with an ohmmeter and visual inspection for solder bridges > or stray wire clippings. > > If you have both transmit and receive 8 volt lines (collectors of CB Q1 > and Q2), then check the gates of CB Q3 and Q4. For receive, the gate of > Q4 should be high (4.5 to 5 volts), and the gate of Q3 should be near > zero. If these last conditions are true, the microprocessor outputs for > transmit and receive are correct and the most likely failure is a > shorted Q3. > > Let us know the results of those tests. > > 73, > Don W3FPR > > CJA wrote: >> I have a K2 with a KPA100 and KAT100 in a separate enclosure. It had >> been >> working on my lossey loop but I decided to try a ground mounted Hi-Q >> 4/160. >> After connecting the antenna, I began trying to tune to the various >> bands. >> It seemed to be tuning to a low SWR when the control panel just froze up. >> The VFO would not change the freq and none of the buttons functioned. I >> turned it off and on several times and came up with the full elecraft in >> the >> LCD and then the last freq I was on. The control panel was still frozen. >> I >> then tried to reset. That did not work. Now it just goes through the >> POST >> (full elecraft in the LCD) and seems to go into transmit (dummy load >> connected) with a high pitched tone and hangs there. Any suggestions >> would >> be greatly appreciated. 73, Chris Amyes, K7CJA >> >> ------------------------------------------------------------------------ >> >> >> No virus found in this incoming message. >> Checked by AVG - www.avg.com >> Version: 8.5.409 / Virus Database: 270.14.1/2407 - Release Date: 10/01/09 >> 06:34:00 >> >> > ______________________________________________________________ > 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 > > -- View this message in context: http://n2.nabble.com/K2-CONTROL-PANNEL-FREEZE-UP-K7CJA-tp3749758p3945996.html Sent from the [K2] mailing list archive at 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
