It's not surprising you see coupling between Ant 1 and Ant 2 ports, at a
low level.
It's not quite "fair" to test levels on an unterminated antenna port.
Better to connect an unused port to a 50 ohm load before making this
test. It should reduce the apparent coupling. That's because some of
the power coming in on (say) antenna 1 gets coupled to the antenna 2
jack and wants to flow OUT of the Orion. A 50 ohm load will "catch"
that power. An open circuit reflects it back into the antenna 2 input.
In any case, the isolation seems to be good enough for ham work.
Another interesting Orion "feature": when you connect only the main rx
to ant 1, say, you get a certain S meter reading. If you also connect
the sub rx to ant 1, the main S meter goes down by about an S unit.
This makes some sense, since the incoming power is split two ways, but 3
dB should be 1/2 S unit.
73 Martin AA6E
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