Interesting chat. The Oahu radar was aSCR-270 radar. They were quite effective, once they were believed in. One was mounted on the south facing peak of Cadillac in Acadia National Park, Bar Harbor, Maine in 1942 It was tower mounted at an elevation of around 1500 feet. The entire area was of course closed off to civilians, but the locals came to the conclusion that it was for spotting German subs and planes. Not quite. It was operated by the Army and the MIT Draper Radiation Labs. It simulated an airborne radar, as on might be carried by an aircraft. The return signal was beamed, as a TV signal to Hanscom Airfield, in Cambridge Massachusetts, ruffly 225 miles down the coast, where it( the image of the scope return, was displayed on a remote scope. Roy, you may see where this is going. Once the signal transmission issues were overcome, the next step was to put a radar in a plane, witch was done with the TBM Avenger being modified. Hence, the birth of airborne early warning radar. Everything was torn down post was. Not even a plaque to mark the achievement.
https://warhistory.org/@msw/article/project-cadillac