Jason, AG4DG wrote:
"3. Connector for the noise antenna"

Eliminate the noise antenna for simplicity. Signal at the radio can be
delayed to allow silent disconnect before noise arrives to upset it.
Like noise squelch, representative interference can be sensed outside
the receiver passband from a common antenna. But sensing large
interfering signal impulses requires more reception independence than
does noise squelch reception of background noise. But it doesn`t require
separate antennas as does space diversity reception.

Best regards, Richard Harrison, KB5WZI