On 6/17/2020 9:13 PM, Peter Dougherty
[Edited Message Follows]
I'm having a problem with false FT8 positives firing off
I grid chase (and DXCC chase) on 6m. With my cluster
connections up and WSJT and JTAlert-x connected, I get frequent
hits for stations where the grid information is incorrect. I'm
not talking about "gibberish spots" here, but legitimate spots
that trigger incorrectly.
The source, according to Spot Collector, is my own copy of
WSJT-x. There have been numerous examples of a spot arriving via
WSJT-X with one (ostensibly) correct grid, but it shows up in
the DX Grid column in S.C. with a different grid, causing alerts
to sound. I could understand if this was a station I'd worked
previously and an old grid was being auto-populated, but this
happens even with stations I've never worked before.
One such station CQs on FT8 from grid EM31, a grid I have
previously worked, confirmed via LoTW, and verified for VUCC
credit. The station shows up correctly in WSJT and JTAlert-X,
but in Spot Collector it's showing this particular station as
EM43, one of only two EM grids I've never worked. This isn't the
only circumstance, but since the op in question (AC0RA) is an
avid 6m operator with a good signal to me, alerts on his call
are frequent. But with many others the same thing is happening.
JTAlert-x/WSJT has the grid correct according to the CQ sent by
the originator, but S.C. gets it wrong.
AC0RA is an AVID Rover and has recently been in EM43...
Now, if this isn't already the case, I would respectfully
suggest than any incoming spot for a station previously worked
that has grid information populated by the FT8 software, that
information needs to override any previous grid info from past
QSOs in DXKeeper. Obviously this would be especially needed for
Rovers. I have a suspicion that this is already the case, but I
wanted to mention it here just in case. But with that said, I'd
really like to understand why I'm getting so many false
And speaking of false positives, when the inevitable
gibberish print from WSJT causes a "need" alert is JTAlert (and
subsequently in Spot Collector), is there any way to maybe put
in a lookup or truth table, etc, within S.C. so I won't get
woken up by a badly interpreted FT8 "spot"?
Or some way to say "only alert if X number of "new grid" or
"new zone" (etc) spots are received within Y minutes? I'd
typically want to set that at 3 within 1 or 2 minutes