I have a Radio Shack roof top antenna, I bought about five years ago,
it still works great.

It's a long range antenna, model vu 210, the best one they made, but
they don't make it anymore.

I had a similar antenna about thirty years ago, it seemed to have a
longer range

I lived in rural upstate New York lots of mountains, but I could get
stations as far away as 141 miles, namely Ottawa and stations 75 miles
away like Montreal.

But here in the Chicago area flat terrain and the same hight, I get
Milwaukee very clear, but nowhere near the range I got years ago.

I have a theory, that it might be that the flat 300 ohm wire used in
those days had better reception, and I know a lot more interference.

Right now I am using rg6 quadshield cable and have a high end booster
connected.

Is my theory correct about the wire?