"> How does your KAT500 know what frequency to use? Does it have a serial data interface or does it depend only on the internal RF counter? >
W7BRS> AUX cable between K3 to KAT-500 and KAT-500 to KPA-500. They are in serial communication per Elecraft protcol(s), whatever those are. > What KAT500 mode (AUTO, MAN, BYP) is selected when you observe this anomaly? W7BRS> Per manual for KAT-500/KPA-500 the stated "nominal" mode is MAN. So I leave the KAT-500 in MAN *after* tuning the antenna to 1.1." Your problem sounded a bit like the conflict between serial data frequency and RF count when operating near a "bin" boundary. However, my only experience with that problem is with Kenwood rigs using serial data to provide frequency to KAT500. I have no experience with AUXBus. For Kenwood owners one solution was to use the FDT command to desensitize the RF counter so serial data frequency always had priority. The command description implies it is equally applicable to AUXBus so may be worth experimenting. "FDT Frequency Counter Distance for Retune GET format: FDT; SET/RESPONSE format: FDT nn; where nn is the distance, in kHz, between the current ATU frequency and the most recent TX frequency count for the ATU to change ATU settings to the new frequency. The value is between 0 (interpreted as the default of 10 kHz) thru 65535, which disables ATU tuning based on frequency count. This is intended for customers that prefer the KAT500 only follow the frequency provided by a serial port command or the K3/K3S/K4 AUXBUS, or select a minimum distance between current ATU frequency and a newly counted frequency. FDT was introduced in firmware version 01.99." 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 arch...@mail-archive.com