Hi Tony, My K2 is working fine as well. I measured the KSB2 U1 voltages as described by Don W3FPR and they appeared to be correct.
Apparently, the problem was caused by my K20 CW keyboard, cf. http://k1el.tripod.com/k20info.html With the key plug of the K20 CW keyboard plugged into the key jack of the K2, SSB receive signals decreased after I pushed the MH2 PTT button. After unplugging the K20 keyboard from the K2 key jack, SSB receive signals were back to normal signal strength. Next time I want to do some SSB or PSK31 I have to remember that the CW keyboard needs to be unplugged from the K2. Thanks to you, Don and everyone else for the great support. vy 73, Gunter PA3HGC "N2TK" <[EMAIL PROTECTED]> wrote: > Hi Gunter, > I do not know if this helped you or not. I did not take off the > covers of my K2 since it seems to be working fine. If I convert my > XV50 to a XV144 I will check out the problem. > > Good luck with your problem. > > 73, > N2TK, Tony > > _____ > > From: N2TK [mailto:[EMAIL PROTECTED] > Sent: Monday, February 04, 2008 5:05 PM > To: '[EMAIL PROTECTED]'; 'PA3HGC' > Cc: 'Elecraft Discussion List' > Subject: RE: [Elecraft] K2 - hang up problem > > > Well, I got my K2 working again. Don't understand why, but it is > working fine. > > My K2 sits on a XV50. I had unplugged the 12V to the XV50 to use the > 12V line for the K3. It turns out if I unplug the 12V line to the > XV50 I also need to disconnect the RS-232 line between the K2 and > XV50, even though the XV50 is not ON. Then the K2 works fine on SSB > (it always worked fine on CW). > > > If the 12V power is plugged into the XV50 the RS232 line does not > matter whether it is plugged into either the K2 or XV50 or both. But > if the 12V power is removed from the XV50 the RS232 must be removed > so the K2 works on SSB. > > Maybe over a beer I need to look at the schematics to see what this > is all about. As always, ideas are welcome. > > Tnx for all the suggestions. Amazing how much help was offered. > > How about those Giants! > > 73, > N2TK, Tony > > _____ > > From: Don Wilhelm [mailto:[EMAIL PROTECTED] > Sent: Saturday, February 02, 2008 5:50 PM > To: PA3HGC > Cc: N2TK > Subject: Re: [Elecraft] K2 - hang up problem > > > Wow, two with the same problem at the same time - that is unusual. > You guys will have to take some measurements to guide me in the right > direction - right now it seems like the problem is on the KSB2 board, > but we need to confirm or deny that. > > Open the K2 top cover - if a KPA100, lay it on a box to the right of > the K2, but leave it connected. > Receive with the OP1 filter for now. > Then try to create the problem - when it occurs, it is time to take > some measurements. > Is RXS (U1 pin 21) high (5 to 6 volts)? It should be. > Are TXS (U1 pin 15), TXC (U1 pin12), and RXC (U1 pin 22) all low > (near zero volts). They should be. > If those signals are in the correct state for SSB (or RTTY) receive > with the OP1 filter, then the firmware chip on the KSB2 board is > doing what it is supposed to. If not, then there is some firmware > fault or some signals are not getting from the K2 to the KSB2 board. > > If the signals are correct and the failure persists, then the task is > to follow those signals into the diode switches for the filter and > try to find what is bad. It could be an unsoldered or poorly > soldered connection. You may want to reflow the solder on all the > diodes near the filter and the R-paks too. > > 73, > Don W3FPR > > PA3HGC wrote: > > Don, Tony, > > > > Get an error message when posting to the Elecraft reflector ("Your IP > is > > in nl, rejected based on geographical location"), so I try to approach > > you directly. > > > > Since last week I have the same problem with my K2 # 703 on all bands, > > i.e. receive and transmit in CW is perfect, receive in SSB and data > > modes is okay, only if I push the MH2's PTT key in LSB, USB or data > > mode and let the K2 go back to receive, the receive signals are much > > weaker than before (typically from S9 before keying the PTT to S1 > > afterwards). I can only get back to normal reception by switching > bands > > or by switching the K2 off/on. > > > > My control board firmware is 2.03d, and the KSB2 firmware is 1.07. > > I have already resoldered the sockets of the firmware chips on the > > control board and the KSB2 adapter and reseated U6 and U1, but the > > problem persists with both the 10W K2 and the KPA100/KAT100-2 (in > > EC2 enclosure) attached. > > > > Thanks and 73, > > Gunter PA3HGC > > > > > > W3FPR wrote: > > > > > > Try reseating the firmware chip on the KSB2 board, and if > > that does not help we can begin looking at various voltages on the > > KSB2. The signals that switch the filter are RXS, TXS, TXC and RXC. > > > > 73, > > Don W3FPR > > > > > > > > > > > > > _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. 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