I just tried an experiment with a K3S and KPA1500, which uses the same AUXBUS frequency mechanism as the KAT500. The KPA1500 has an LCD display of the XCVR frequency, as sent by the K3S/K3 over AUXBUS. It comes in multiples of 8 kHz.
I set VFOA to 14015 and VFO B to 14074. When I turn on the transceiver (not in split), the KPA1500 reports the XCVR frequency as 14008. I then pressed (a "hold") the K3S SPLIT button, and the rig's LCD shows an arrow to the VFO B frequency as the transmit VFO. The KPA1500 reported that the XCVR frequency changed to 14072. Then I engaged XIT and dialed in 9.99 kHz. When I turn XIT on and off, the KPA1500 display alternates between 14072 and 14080. The KAT500 owner's manual on page 16 says that the KAT500 can follow changes in the K3's VFO frequency during receive. That means that you don't have to transmit to get frequency information from the K3S/K3 to the KAT500/KPA1500, the frequency information comes from the K3/K3s when it is receiving. The K3S/K3 can send the VFO frequency as it changes, by moving the transmit VFO frequency with a knob (the VFO B knob when in split). The frequency is sent shortly after VFO encoder motion ceases. You need to turn on this capability by a K3 menu, CONFIG:KAT3 and tap the 1 button to toggle between KAT500N and KAT500Y. Give it a try yourself. The KAT500 has a serial command "F;" that returns the KAT500's last-known frequency, which comes from either AUXBUS or the frequency count of the last transmission. You can use the F setter from a computer program to set the KAT500's frequency if you prefer. You should send the desired TX frequency. 73 de Dick, K6kR From: Andy Durbin <a.dur...@msn.com> Sent: Wednesday, August 21, 2019 18:58 To: Dick Dievendorff <d...@elecraft.com> Subject: Re: [Elecraft] KAT500 follows K3 RX freq "K3 and K3S provide the TX frequency on AUXBUS, dealing with split and XIT." Dick, I can find no Elecraft specification for the data sent on AUXBUX but the discussions on the reflector seem to consistently indicate the AUX BUS frequency is the RX frequency not the TX frequency. Can you please point me to any Elecraft documentation that says the AUXBUS carries the TX frequency. Thanks, Andy, k3wyc _____ From: Dick Dievendorff <d...@elecraft.com <mailto:d...@elecraft.com> > Sent: Wednesday, August 21, 2019 4:58 PM To: 'Andy Durbin' <a.dur...@msn.com <mailto:a.dur...@msn.com> > Subject: RE: [Elecraft] KAT500 follows K3 RX freq K3 and K3S provide the TX frequency on AUXBUS, dealing with split and XIT. -----Original Message----- From: elecraft-boun...@mailman.qth.net <mailto:elecraft-boun...@mailman.qth.net> <elecraft-boun...@mailman.qth.net <mailto:elecraft-boun...@mailman.qth.net> > On Behalf Of Andy Durbin Sent: Wednesday, August 21, 2019 14:17 To: elecraft@mailman.qth.net <mailto:elecraft@mailman.qth.net> Subject: [Elecraft] KAT500 follows K3 RX freq " All I do is change RX frequency on the K3S and every thing else follows. No RF required to switch things to the correct configuration for band, frequency and antenna." I think that having the KAT500 follow the K3 RX frequency is a really poor system design. The tuner, and the tuner's frequency dependent antenna selection, should follow the transceiver transmit frequency. Why does it matter? Well one day you will transmit with a large difference between TX and RX frequencies into the wrong antenna and with the wrong tuning solution. This will fault the KAT500 and/or the KPA500 and could possibly cause damage. It actually works a lot better if the KAT500 and KPA500 follow the rig TX frequency and are properly configured before the transmission starts. 73, Andy, k3wyc ______________________________________________________________ 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 d...@elecraft.com <mailto:d...@elecraft.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
