KAT500 has an input attenuator that may, under certain conditions, be activated during a full search tune. Page 1 rev C of the KAT500 schematic shows the attenuator is a divider consisting of R6 and R7 which are both 39 ohm. My KAT500 serial number 2609 does not have R7 fitted and R7 is shown as not populated in Figure 17 of KAT500 User's Manual Rev C6.
The removal of R7 changes the potential divider into a simple series resistor and my measurements show my KAT500 presents a very poor match to my TS-590 exciter when the attenuator is active. In this example the KAT500 was in bypass and connected to a nominal 50 ohm dummy load. The impedance presented to my TS-590 by KAT500 was measured with an LP-100A: Att Out: R 48.1, X 2.4, Pwr 4.48, SWR 1.06 Att In: R 22.3, X 162.6, Pwr 0.55, SWR 9.98 Do other KAT500 owners see similar results? (Attenuator can be switched in/out with KAT500 utility) Can someone please explain why the attenuator was changed. Thanks and 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 arch...@mail-archive.com
