So now we have it for certain. The reflected signal from an Aircraft will always fall in frequency due to the fact that the reflected signal path decreases in Length as it approaches the TX RX path and increases as it goes away.
The previous Captures have all proved this to be true.
This Capture of G4FCC signal at my QTH on 6m is the exception. What is the Aircraft doing in this instance at the start of the trace?
The clue could lie in the fact that Sywell Airport lies to the north of our signal path and within a few Kilometres of my QTH. The signal is short lived so could well be reflected from an Light Aircraft manoeuvring to land.
skip2468
We can always learn.