[Elecraft] KAT500 investigation results (WAS KPA-1500 issues)

[ANDY DURBIN]

"I had always wondered why the KAT utility reported frequency values that were frequently quite different from the actual transmit frequency. It  turns out that the "Observed Frequency" value displayed in the utility  Operate window is the low end of the particular tuning bin that has been  selected by the selection algorithm. "

I don't think that is correct.  From my experimental observations I believe the last observed frequency (the value returned by the F; interrogation) is the most recent value of F received over the serial interface unless that value has been changed to a more recent RF detected frequency.  RF detected frequency has a resolution of 8 kHz which may or may not match the size of a tuning segment.

(There is an exception to this though - If the last value of F received over the serial interface caused a KAT500 band change then the last observed frequency will be stuck at zero until another F transmission is made or until an RF transmission is made . This anomaly has been reported to Elecraft and it's "on the list")

The behavior of last observed frequency does not change if the KAT500 is in bypass mode where no tuning solution is being selected. 

it is my understanding that the KAT500, when connected to a K3, actually tracks the K3 receive frequency not the transmit frequency.  My TS-590 Elecraft interface gives the KAT500 the calculated transmit frequency not the receive frequency which seems to me to be a better implementation. ( I had enough problems with my SteppIR retuning at the start of a split TX to want to play the same games with my KAT500 and KPA500)

Andy, k3wyc