First pic is ammeter with the radar running: 1.5 amps at 12.5 volts DC.
Second pic is scan from the boat today of La Conner north basin looking west out to the channel. Not to shabby. I have a lot to learn now, do some tests and tuning next time up to the boat.
I got power to the new dome through a couple wires in the old radar cable. The old cable is 14 pin for an analog radar. That cable routes through the overhead in the cabin and down a corner for over 25 feet. Did not make sense to tear out all the overhead to route a cable for 1.5 amps of 12 volts DC.
The schematic shows tying the shield for the power cable to ground at both ends. Its tied to the the antennae chassis in the dome. I have not carried the shield ground back to the boat yet, see how it behaves with the shielded cable run down the radar mast for 7 feet open-ended.
All this was less than a boat buck: radome and 15 meter cable. Plus a day or two of retired labor.
If you want to check it out sometime, let me know, my winter schedule is TBD to mid Jan.