[Skimmertalk] Notching out FT8 frequencies to reduce CPU load of RTTYSkimServ

[Bob Wilson, N6TV]

Depends on your hardware and sampling rate.  Use 192 kHz sampling if
possible to cover the most frequencies.

See https://groups.io/g/RBN-OPS/message/1793 for more info.

For QS1R, see

http://reversebeacon.blogspot.com/2014/01/want-to-spot-beacons-heres-how.html

73,
Bob, N6TV

On Fri, Jun 15, 2018, 9:55 PM Ron Castro <ronc at sonic.net> wrote:

> Bob:  What should the center frequencies be set for?
>
>           Ron Castro
>            N6IE
>     www.N6IE.com
>
> Member:
>                   ARRL
>      Redwood Empire DX Assn.
> Northern California Contest Club
> Northern California DX Foundation
>   Society of Broadcast Engineers
>
> -----Original Message-----
> From: Skimmertalk <skimmertalk-bounces at contesting.com> On Behalf Of Bob
> Wilson, N6TV
> Sent: Friday, June 15, 2018 3:30 PM
> To: SkimmerTalk Reflector <skimmertalk at contesting.com>
> Subject: [Skimmertalk] Notching out FT8 frequencies to reduce CPU load of
> RTTYSkimServ
>
> Clicking on the "Band scope" button in RTTY Skimmer Server reveals that
> RTTY
> Skimmer creates a *lot* of "decoders" (yellow dots) as it attempts to
> identify and process signals that it cannot possibly deal with.  This
> wastes
> a lot of the CPU time.
>
> To reduce the CPU load, I changed the RTTYSegment section of my
> RTTYSkimServ.ini file to ignore most of the known FT8 frequencies between
> 80m and 15m where most of the activity seems to be (at present):
>
>
> RttySegments=1800000-1820000,3520000-3571000,3577000-3600000,5330000-5407000
>
> ,7020000-7071000,7077000-7100000,10130000-10132000,10139000-10150000,1406000
>
> 0-14071000,14077000-14150000,18109000-18115000,21060000-21071000,21077000-21
> 150000,24910000-24930000,28060000-28150000,50250000-54000000
>
> (Of course this statement must be on a  *single long line*; email programs
> may show this statement as multiple lines due to line wrap).
>
> The reduction in CPU utilization was immediate and noticeable.  My i7-7700
> PC has a variable speed cooling fan, the higher the CPU utilization, the
> louder the fan.  It's much quieter now, and I'm still decoding RTTY spots
> just fine.
>
> I'm not sure if I should remove these FT8 frequencies during RTTY contest
> weekends.  Last time I checked, the FT8 guys were still going strong with
> little if any RTTY contest activity in the FT8 frequencies, but I haven't
> tried to analyze the raw data files to see how many RTTY spots were posted
> to these FT8 frequencies that I'm now ignoring.
>
> 73,
> Bob, N6TV
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