Walt/K5YFW wrote: > if 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 3 different signals will sum at the receiver, but, having each one a different phase, the sum is destructive with the result that they tend to cancel. If the paths are stable you notice a drop in the signal strength but if paths are unstable (as it is often the case) one signal may win over the others and the phase of the PSK decoder will wander back and forth. The clock recovery is also problematic because of the unstability of the reference. Among the possible solutions to multipath there is the spread spectrum modulation (as in Chip64) where the symbols at the receiver aren't expected at a precise timing, but are decoded in a "clockless" manner. In Chip64 signal scope you can actually see the signal trace wandering left and rigth due to path hopping or see the ghosted trace of the secondary path. Nino/IZ8BLY
