[Skimmertalk] CW frequencies for 6m?

[Bob Wilson, N6TV]

On Wed, Dec 5, 2018 at 6:37 AM Björn Ekelund <bjorn at ekelund.nu> wrote:

> Now the question is which frequency range I should chose?
>

With my "secondary" Red Pitaya, I scan the 7 least-used bands, including
6m, CW only.  Center frequencies were modified to get the most sensitivity
at the lower band edges (with the default skimmer settings, sensitivity
rolls off before you get to the band edge, as seen on HDSDR):

CenterFreqs192=136750,475000,1885000,3585000,5417000,7085000,10185000,14085000,18153000,21085000,24975000,28085000,28255
000,50085000,50255000
SegmentSel192=111010000010110
CwSegments=135700-137800,472000-479000,1800000-2000000,3500000-3600000,5330000-5407000,7000000-7125000,10100000-10130000
,14000000-14150000,18068000-18115000,21000000-21200000,24890000-24935000,28000000-28300000,50000000-50200000

For my "primary" Red PItaya, I scan the 7 "most-used" bands, *both* CW and
RTTY:

CenterFreqs192=475000,1885000,3585000,5417000,7085000,10185000,14085000,18153000,21085000,24975000,28085000,28255000,500
85000,50255000
SegmentSel192=00101111101000
CwSegments=472000-479000,1800000-2000000,3500000-3600000,5330000-5407000,7000000-7125000,10100000-10130000,14000000-1415
0000,18068000-18115000,21000000-21200000,24890000-24935000,28000000-28300000,50000000-50200000

The RTTY Segments are carefully selected to exclude FT8 frequencies,
otherwise RTTY Skimmer wastes much CPU time on your PC trying to decode FT8.

RttySegments=1800000-1820000,3520000-3571000,3577000-3600000,5330000-5407000,7020000-7071000,7077000-7100000,10130000-10
132000,10139000-10150000,14060000-14071000,14077000-14150000,18109000-18115000,21060000-21071000,21077000-21150000,24910
000-24930000,28060000-28150000,50250000-54000000


> I am currently running my skimmer at the 96kHz setting and it would of
> course be easy to step that up to 192kHz but that means noticably increased
> heat
> in both my Red Pitaya and skimmer PC.
>

Red Pitaya should have a 5V fan powered via the two header pins next to the
Ethernet connector (positive pin is the one closest to the center of the
board).  i7 PC should be able to handle RTTY skimming better if you exclude
the FT8 segments as shown above.  CW skimming alone should not stress a
modern CPU at all even with 8 bands x 192 kHz.

My current setting is running the skimmer to cover the 50,060-50,151 range
> with the 96kHz setting.
>

Try 192 kHz.


> What you have others set it to?


FYI, you can see the ranges scanned (and FT8 frequencies ignored in my
case) at http://reversebeacon.net/nodes/detail.php (Detailed node list).  I
don't have a decent 6m antenna yet so I never get any spots there though.


> Are there other considerations, like beacons?
>

All CW beacons should definitely be spotted by Skimmers if possible.  See:

http://reversebeacon.blogspot.com/2017/09/beacons-revisited-checklist.html

73,
Bob, N6TV