Effect of KPA1500 Antenna Selection

[Edward A. Dauer]

Does anyone know whether the antenna output not selected is shorted somewhere near the output itself, or just left open while the selected output socket is active?  I haven't ever seen a schematic; the "Theory of Operation" in the Manual is too oversimplified to answer the question; and although I could measure the resistance across the unselected output, it wouldn't tell me if the connection to ground is near the socket or way upstream past some low-resistance inductor.  And a related question, what happens to the two antenna outputs when the power to the amp is off?  Are they latching relays or does everything get de-energized and fall to a default open?

TIA,

Ted, KN1CBR
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[ANDY DURBIN]

KAT500 leaves unselected antenna ports open circuit and defaults to port 1 when power is removed.  The relays are not latching.

I don't have details for the KPA1500 but the ATU board photos available here -  https://fccid.io/UTR-KPA1500  - have high enough resolution to trace the  output signal paths.

I have been told these photos are of a prototype and may not represent the production configuration.

73,
Andy, k3wyc
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