[Elecraft] Aircraft Doppler shift

[Jim Brown]

Andy,

My observations here are consistent with yours -- I regularly see 
Doppler on either side of a signal, sometimes even both sides, which 
would be consistent with multiple aircraft. And without Doppler, I 
always see low level sidebands on locals that are approximately 
symmetrical with the P3/SVGA cranked to minimum span. Last season, Trey 
and I were seeing a neighbor being much wider than normal. Trey went to 
his shack to help him figure it out while I watched on the P3. It was 
coming from his Expert amp, and we managed a modest improvement. If I'm 
remembering correctly, he was running the amp on the low voltage setting.

73, Jim K9YC

  On 7/23/2023 6:30 PM, Andy Durbin wrote:
> The aircraft that can be expected to cause Doppler shifted reflection in the Phoenix Class B airspace are transport aircraft following Standard Instrument Departures (SID) and Standard Terminal Arrival Route (STAR) routings.   My QTH is about a mile from a KPHX STAR (BRUSR ONE).  On a busy day with winds out of the East they go by at about one per minute.  As they approach from the North I would expect reflections with a higher frequency.  After they pass and move to the South I would expect  reflections with a lower frequency. With multiple aircraft following  the same route I would expect a mix of reflected signal frequencies spread on each side of the transmitted signal frequency.