Powering up without antennas connected

Is it safe to power up an A5C to configure it without anything attached to the antenna ports?
Is it safe to run an A5C with only two antenna ports in use?

It most definitely ok to power up with nothing attached! No attenuators required.

It is safe to run with only two ports, but you will need to do the terminated attenuator plugs for the other two ports.

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