[Skimmertalk] 192 vs. 96 Khz on QS1R

[Bob Wilson, N6TV]

Jeff,

It sounds like the settings of the two CW Skimmer Servers may not be as
identical as you might think.  It's best to compare the two SkimSrv.ini
files line by line, especially the CWSegments line which defines the
frequencies where decoding will occur.  There are many other settings which
can affect the amount of decodes.  The only differences between the two
.INI files should be the Rate line and perhaps the telnet address.

Another possibility is that the calculation of signal to noise ratio is
being affected, since the "noise" level is actually determined (in VE3NEA's
code) by averaging the *entire* band being sampled, including phone and
digital segments on some bands.  Those spurious signals may "raise" the
calculated noise floor, causing fewer stations to get spotted on the wider
receiver (stations below a certain minimum S/N are not spotted at all).
But if very oud signals are not being spotted by the wider skimmer,
something may be wrong.  Of course you have to start both Skimmer Servers
at exactly the same time since each will spot a CQing station only once per
ten minutes unless they QSY.

Using CWSL_Tee and HDSDR reveals the entire sampled segment, which may be
show you some signals outside the passband of the narrower SDR that are
affecting things, especially intermod from loud nearby FM broadcast
stations.

73,
Bob, N6TV

On Tue, Jun 25, 2019 at 1:11 PM Jeff Blaine <KeepWalking188 at ac0c.com> wrote:

> I have two identical QS1R feed with a splitter.  One running 192 Khz and
> the other 96 Khz.  It seems that I get about 1.5-2x the spots out of the
> 96 Khz width skimmer with (as far as I can determine) exact settings.
> If I bump the 2nd one from 96-->192Khz, the spot rate is very similar.
> Wondered if anyone else has seen this and what may be behind it.
>
> Another pretty weird thing is with the two skimmers setup and running
> identically, about 2/3 of the time they will decode the same set of
> calls.  And the other 1/3 of the time one **OR** the other will catch
> the guy, but not both.
>
> >
> > 73/jeff/ac0c
> > alpha-charlie-zero-charlie
> > www.ac0c.com
> >
> >
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