Problem identified!
The cable run was the problem. Got some connectors from Home Depot, ran the cable to tuner. After scanning I got 35 channels including WNAC and WPRI! All crisp clear and no breakups.
Very very happy now
Thank you all very much for the prompt and comprehensive responses. This community is great.
In short, for anyone tuning in this thread: Get a decent rooftop antenna and never look back