What is the approximate maximum distance along the Earth's surface normally covered in one hop using the F2 region?
Why The F2 region is the highest ionospheric layer, typically 200 to 300 miles up, so a signal refracted from it can return to Earth roughly 2,500 miles from the transmitter. The maximum hop distance is set by geometry: the higher the reflecting layer and the lower the takeoff angle, the farther the skip. That is why worldwide contacts on HF usually require several F2 hops.
Watch out The choice around 1,200 miles is the classic single-hop distance for the lower E region, which is only about 70 miles up. The 12,000 mile figure is roughly halfway around the world, which takes multiple hops, not one.
E region low, about 1,200 miles; F2 region high, about 2,500 miles. Higher layer, longer hop.