[WriteLog] Writelog skimmer window

Wayne support at writelog.com
Fri Sep 21 11:17:00 EDT 2018


> I saw a resent publication that showed a RTTY skimmer window in Writelog. I
> re-read the writelog manual and didn't see any reference on how to set up
> the skimmer.

I suspect you are confusing WriteLog's SDR support with a skimmer.

To define terms:
A "skimmer" is a software package that reads a digitized radio IF stream
and decodessignals across that entire IF. A "CW skimmer" decodes CW, and
a "RTTY skimmer" decodesRTTY. Running one skimmer produces many CW streams
(or RTTY streams.) There is notechnical reason a single skimmer cannot
decode many different modes (CW, FT8, frequency-shiftRTTY, and even, in
principle, SSB using voice recognition.) The last I looked, the skimmer
packages available only did one mode at a time, but multiple skimmers can
be connectedto a single IF stream to get multiple modes out.

An "SDR" (software defined radio) is a device that produces an appropriate
digitized radioIF stream that can be fed into a skimmer (or skimmers.)

WriteLog version 12 (since January 2016) supports SDR input. But WriteLog
does not "skim".It converts the SDR stream(s) into spectra that it then
displays on its Band maps. The easiestway to access a skimmer is to connect
to a packet cluster that distributes skimmer spots.Of course, you will
getting calls skimmed from whatever receiver(s) feed the packet cluster
as opposed to your own receiver/antenna.

If you want to skim only your own SDR, then you're going to have to install
and run theappropriate simmer software at your own shack, figure out what
data you want from it,and figure out how to get that data into wherever you
want it in WriteLog. I vaguely say "figure out what data" because a
skimmer,
at its lowest level, provides every single CW (or RTTY) character it finds
in its input stream from the SDR. Skimmer software, in additionto that
decoding, also has some scheme for parsing those characters into a
callsign along with a guess about whether that callsign belongs to a
station
calling or answeringa CQ on that frequency. (If you really want to get
technical, notice that guess really ought to take into account what contest
is in progress: the Sprints are quite different.)

Wayne



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