If you’ve read the How to work DX section then you might have caught on to some key ingredients, specifically with the antenna, that make communications possible over a long distance.
Of course if you’re not looking to work a station thousands of miles away but rather a few hundred miles away (say, within 300 miles) we’ll need to talk about Near Vertical Incidence Skywave or NVIS.
Basically, this is a technique for using an antenna that is close to the ground so the angle of radiation is high.
Because the angle is high, the angle of incidence is also high yielding a signal range that is fairly close.
NVIS generally requires lower frequencies to work properly (think 7MHz and down) due to absorption and reflection properties of the ionosphere.
If you select a frequency that is too high the RF energy can pass straight through the ionosphere without being reflected at all.
Of course selecting a frequency too low will yield absorption of the RF energy by the ionosphere and your signal will also never make it back to Earth.
Generally speaking, 40m and 60m is best for daytime use while 60m and 75/80m is best for nighttime use.
So, following what we learned in the How to work DX section, we just need to use an antenna that is bad for DX.
Something that radiates up instead of out.
If we look at the dipole antenna we see that we should have it elevated to one wavelength above the ground for good DX.
Lowering that antenna to almost ground level (an eighth to a quarter wavelength above the ground) makes the radiation pattern go from 5 to 15 degrees to basically one huge lobe that is pointing straight up!
Now you know why many hams have so much wire in their trees!
Some antennas are for talking around the corner while others are for talking around the world!