Jack - good evening (or maybe good morning!). Great info and thanks for the quick response. I have my setup exactly as in Fred Cady's KX3 book, towards the end of the book. He has a great diagram showing how to run a KPA500 from a K3 or KX3. Do you have his book? If not I'll respond and tell you what I've got. Also, yes - I have current f/w levels on all my equipment. And your other item, yep - I'm always careful to have the "other" radio completely powered off before doing anything with either.
73 - time for Santa to start hauling presents from the attic to the Christmas tree - the two boys are finally asleep in their rooms! Jim Bennett / W6JHB Folsom, CA > On Dec 24, 2014, at 10:17 PM, Jack Brindle <jackbrin...@me.com> wrote: > > The KPA500 is my work, so I’ll try to answer… > See discussion below. > >> On Dec 24, 2014, at 9:22 PM, James Bennett <w6...@me.com> wrote: >> >> First, let me wish all a very Merry Christmas! > > And from the W6FB family as well! > >> OK, now the problem. I have a KX3 and the full K-line: K3, P3, KPA500, and >> KAT500. I have a two position coax switch that I use to drive the amp with >> either the K3 or the KX3. When using the K3 (P3 powered off) all works >> perfectly. I can change bands by pressing the appropriate band button on the >> amp or changing bands on the K3. Doing either results in the amp display >> changing to the associated band. > > When the KPA500 is set for RADIO = K3 and the K3 is on, this is the correct > behavior. Pressing a band button sends the button info to the K3 using the > Auxbus serial communications. The K3 responds by changing bands, then the KPA > responds to the BAND lines change by changing bands itself. Note that the > button push on the KPA only causes a command to be sent to the radio, it does > not directly cause a band change in the KPA500. The behavior is different for > all other RADIO settings. In those cases pushing a band button causes the KPA > to change bands. The next thing to realize is that when RF is sensed by the > KPA, it will change to the frequency counted band, even if other methods have > told it to go to a different band. Of course if the counted band is the same > as the previous band change, there will be no further change. Hopefully this > is a lot clearer than mud… > > Also note that powering on or off the P3 has no effect on the KPA500. The K3 > must be powered on for the KPA500 integration to work, and must be powered > off completely for the KPA500 to mostly ignore it (see BAND discussion below). > >> But.... If I have the KX3 turned on and the K3 off, pressing a band button >> on the amp has no effect. > > This behaves exactly as described above. The KX3 does not have Auxbus, so it > will not receive the button command from the KPA500 and thus nothing will > result. > >> The only way to change bands on the amp is to set the KX3 to the desired >> band and then tickle the amp with a little shot of RF. > > As expected. Note that the K3 better be completely off when this happens, or > _it_ will respond to the button press, change bands, and cause the KPA to do > something. Also note that the K3 has pull-up resistors on its BAND lines, > causing the signals to be pulled to the +5V rail when they are not being > driven low. A short time after the K3 is powered off, the +5V rail will drop > to 0V. The pull-ups will continue to do their job, pulling the lines to 0, > which tells the KPA to change to 60 meters. > >> Now, the bad news. It does not do this all the time. Not 100% certain, but >> it seems to act like this if the amp has been powered off for a few hours. >> Just a couple minutes ago I was doing some sleuthing on this issue. After >> having the K3 online and sending RF, I tested this out and the amp >> subsequently behaved as it should after a K3 shutdown and KX3 startup. The >> amp changed bands with its own buttons or via RF from the KX3. Hmmm… > > Exactly how do you have the K3 and KX3 connected to the KPA500? The K3 loads > the BAND lines at all times (and some other AUX signals), even when it is > powered off. A change in the BAND lines is required to cause the KPA500 to > change bands - if they remain stable then no band change will result. This > means that after the K3 powers off and the +5V rail goes to zero, there > should be just one band change (when the lines drop). After that any band > changes will be due to RF. Do you have some other connection to the BAND > lines besides those from the K3? By far, the best way to connect two radios > to the KPA500 is to use a switch that disconnects the AUX cable from the K3 > before attaching AUX signals to the other radio. Many have noted that you can > generally get away with keeping the K3 connected to the KPA500, but results > cannot be guaranteed. > > You might want to change the RADIO settings to something else (try SERIAL) > when using the KX3 - with no band change reports coming in the KPA will rely > solely on the RF sensing. But, give me a complete description of the setup > and I’ll be able to better analyze the situation. Also, what version firmware > is in the KPA500? The latest is V1.38, which is very highly recommended. The > K3/KPA500 integration code did see several changes in the 1.30 - 1.38 time > frame. > >> Very strange. Anyone (K6KR?) able to shed light on this unusual behavior? >> Not a gigantic big deal, but it does make me wonder what's going on. > > Dick did a great job with the KXPA and KAT500, while the KPA500 is mine. So > many developers, so little time... > > 73! > > Jack B, W6FB > >> >> 73, Jim >> >> Jim Bennett / W6JHB >> Folsom, CA >> ______________________________________________________________ >> 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 jackbrin...@me.com > ______________________________________________________________ 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
