[VHFcontesting] Propagation gurus wanted

[jon jones]

Is the band WA0KBZ referring to 2 Meters?
 
I was active on 2 Meters during the tropo opening from EM18 KS and heard
St. Louis area stations and stations further east at the same time on tropo. I even
recorded both sides of a 2M QSO Aug 26 W0HBH EM48 had with KA2LIM FN12. Both were strong.
 
Stations in Oklahoma were working the tropo as well. Tropo is usually continuous 
 - ie. a station within the duct can often hear all other stations located in the duct.
 
Ducts are sometimes not continuous. Particularly on the western side of the August 20099 duct - 

portions of it moved in and out. Pehaps the Oklamoma stations coupled into a bulge of the duct

running south of St. Louis. The great circle path from, for example, K5SW EM25 to EN91, runs south

of St. Louis. 

 

If K5SW was working a station in EN91, his signal may have traveled to Ohio, then back to St. Louis.
But the direct path from EM25 to EM48 may not have been enhanced at the same time.


This is just speculation - I have personally not heard this form of "tropo-backscatter." But
iono-backscatter is frequently heard on 6 Meters, and at times even on 2 Meters, as others
have noted. Thunderstorm backscatter is noted on the microwaves. 
 
 - Jon N0JK
 
> During the last week's big tropo opening Bill WA0KBZ in EM48 reported
> hearing strong clear signals from Oklahoma off the back of his beam while
> pointed northeast into the duct. Surprisingly when he turned his antenna to
> work them, the OK signals disappeared. This is a characteristic of
> backscatter but there was no ionospheric layer in play to produce any
> backscatter. Has anyone encountered this type of strong clear signal off the
> back of his antenna during a tropo opening? Does anyone have any idea what
> type of propagation might be in play here?"
> 
> I mention this in case there is a decent tropo opening in the September
> contest [don't we hope!] If so you might not want to turn your antenna if
> you hear someone off the back - the signal just might disappear.
> 
> 73 Gene W3ZZ
> World Above 50 MHz
> FM19jd MD
> 50 => 10 GHz
> Grid Pirates Contest Group K8GP
> Member, CQWW Contest Advisory Group