[Elecraft] K3 KXV3 RX Ant Output filter issue

[Skip Munster]

I am interested in connecting a 2nd receiver to monitor other bands using
the KXV3 RX Ant In/Out jacks. For example in the 'RX ANT mode', I have the
K3 on 40m and want to monitor 20m using an external receiver.  However,
there appears to be a 10 MHz low pass filter that is engaged in the K3 when
40m is selected.  If I select 20m on the K3, there is no 10 MHz LPF, and I
can receive 40m on the external receiver.  Why is this?  Is there a way to
disable band pass filters on the RX ANT Out?