Something just ain't right. The resonance point seems a little low. I would have expected it to be closer to 3500 kHz, but that could be due to the height above ground, the feedline, or ... The impedance of 32 ohms also seems a little low at that resonant point, but that may be due to using an unbalanced antenna analyzer on the balanced feedline, plus the feedline length. Feeding your analyzer directly with the ribbon line is probably unbalancing the line. That is where a 1:1 balun would be very helpful. It would decouple you and the analyzer from one side of the feedline. Using W5DXP's calculator would be helpful also. I've put up a lot of doublets over the last 60 years. Most have been about the same length as yours, but typically with 35-50 feet of home made ladder line, typically spaced about 3 inches/7.5 cm. They have been pretty tame and easy to tune through homebrew 1:1 current baluns and simple homebrew unbalanced L-network tuners. Ken I doubled with WA7ARK when posting. But I fully agree with his post.