Coax cables: black is antenna feed, white to second set, yellow to cable feed. White and green is +12vdc and ground.. Or should be. Nor sure where the grey goes or why it's not terminated... Possibly it is satellite feed and should be terminated on the vacant coax through the plate connection??
I would remove the black (temp for a test) and with a barrel connector connect to a TV antenna input, run the antenna up, put at a station and see if the antenna is good... then go from there.
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