Hi Steve,

Thanks for the reply. Can you be any more specific about what
setting decode to "Normal" does, please? I couldn't find it
documented anywhere but probably I am just being inept.

I am aware of two recent changes to the WSPR decoder. One came in
1.9, where I believe inherent phase stability at LF and MF was used
to good advantage. I did extensive side by side testing of that with
the previous version and found this an excellent change. I would not
want to lose that one.

The other change I am aware of came in 2.0 where hashtable.txt is
used to assist very weak signal decoding for known call signs. This
change I would very much like to "lose" permanently. I find the
apparent cost of this increased sensitivity too high for my liking.
I am intelligent enough to recognize false decodes and ignore them.
Unfortunately they get into WSPRnet data and clutter things up, for
which I know of no solution.

73,
Paul N1BUG


On 1/24/19 8:23 AM, Steven Franke via wsjt-devel wrote:
> Hi Paul,
> 
> Recently, we’ve introduced a couple of techniques that have
> significantly improved the sensitivity of WSPR-2. Increased
> sensitivity comes with higher probability of false decodes. The
> next release of WSJT-X will fix a bug that should eliminate some
> of those false decodes - but it will not address either of the
> issues that you have observed. You might consider running with
> decode depth set to “Normal” rather than “Deep”. This will give
> you the same performance that was available under the “Deep”
> setting in earlier versions of WSJT-X. You will lose a couple of
> dB in decoding sensitivity, but you will also see fewer false
> decodes.
> 
> 73 Steve, k9an
> 
>> On Jan 24, 2019, at 4:03 AM, N1BUG <[email protected]> wrote:
>> 
>> I want to report two new behaviors with WSPR in 2.0.0 that were
>> not occurring with prior versions.
>> 
>> 1. Occasionally a known / real call sign will decode with an 
>> incorrect grid. Usually the grid is thousands of miles from
>> where it should be, sometimes in the arctic or the middle of an
>> ocean. A look around WSPRnet confirms this is not limited to
>> me.
>> 
>> 2. I have always had the occasional spurious decode while 
>> transmitting, due to all the noise of receiver overload I
>> presume. I use separate receiver and transmitter (LF and MF).
>> Usually it is 14MDA LR90. Prior to 2.0.0 it would happen a
>> couple times a day or so. What is new in 2.0.0 is that once
>> this decode comes up once, it keeps coming up every few minutes
>> if not every transmission. If I delete hashtable.txt or remove
>> the 14MDA entry from that file, it will then be several hours
>> before I get another of those decodes.
>> 
>> Note: I am not yet certain whether not having hashtable.txt
>> prevents the first odd behavior. I am now running a script
>> which deletes that file after every decode period in an attempt
>> to find out, but it will take some time to be sure. Fortunately
>> WSJT-X does not seem to mind finding itself deprived of
>> hashtable.txt and just silently re-creates it.
>> 
>> 73, Paul N1BUG


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