Tom, Does the problem you describe occur on each of the ANT1 and ANT2 ports on the KAT3 output when the ports are terminated in a good 50 ohm power load?
Have you checked the K3 ANT selection when the KAT3 is installed to be sure that the port to which your 50 ohm load is attached is the one selected on the front panel? The fact that the anomalous behavior occurs with a substitute KAT3 board, and that it doesn't occur with the KANT3 board installed, indicates that the K3's SWR bridge circuit is operating properly. The fact that putting the KAT3 in BYPASS mode provides a correct SWR reading indicates that the relays in parallel with the series-connected inductors are properly switched as are the relays in series with the various shunt capacitors of the L-network (the latter group of relays all switched off their connections to the associated capacitors). You could try the KAT3 tests using manual control mode (as described on p. 56 of the K3 Owner's Manual, rev. D10) to verify proper operation of each of the relays in the L-network individually. The manual control options allow one to read out or clear the per-band memory of the ATU L-C settings, which might also be useful in diagnosis. 73, Mike, K8CN ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
