PSK modes are great on noisy channels. But what about DX channels where you have doppler and other ionospheric modulation?
Also, I pulled out some old data from the 1980s that I ran (I saw it being run and copied the data) and am wondering about it. On a 100 mile NVIS path (using the ionospheric heigth as 175 miles), the first hop would needed to be radiated at 64 deg. The second hop at 76 deg, the thrid hop at 81 deg and the forthe hop at 83 deg. If you are using a dipole or Inverted V antenna with the feed point less than 1/4 wavelength, your antenna radiation pattern will have maximum radiation between 60 and 90 deg. Thus, if you are working another station with the same antenna, you may be receiving 1, 2 and 3 hop signals. How does this affect BPSK and QPSK signals from for example PSK31/63/125? The assumptions is that SNRs are sufficient that the signal strength is not a problme. Tnx & 73, Walt/K5YFW
