[Skimmertalk] Difference of RP10 14 16

Fri Jul 19 20:45:54 EDT 2019

Sorry, I should have said start.sh does not work with the FT8 application.

FWIW, I had put a 20 dB pre-amp on my RP-14 when it was not decoding anything.  It still did not decode anything.  After I changed to chan = "2" it started decoding signals.  I then found my K3, using the WSJT FT8 decoder, could not hear many of the signals that the RP plus pre-amp was decoding.  I then put a splitter after the pre-amp and fed both the RP and the K3 with the amplified signals.  Then the K3 came to life and started hearing as well as the RP.  The pre-amp improves the s/n of the K3 by about 6 dB on 6 meters.  They are now reporting signals with very similar s/n.  I find that I can hear even more signals on 6 that I can't work with my barefoot K3!

Lee VE7CC

----- Original Message -----
From: Bob Wilson, N6TV <n6tv at arrl.net>
To: SkimmerTalk Reflector <skimmertalk at contesting.com>
Sent: Fri, 19 Jul 2019 16:39:19 -0600 (MDT)
Subject: Re: [Skimmertalk] Difference of RP10 14 16

Modifying start.sh works fine for sdr_receiver_hpsdr but not
sdr_transceiver_ft8.  Only one of those applications runs at a time.

73,
Bob, N6TV

On Fri, Jul 19, 2019 at 3:28 PM Lee Sawkins <ve7cc at shaw.ca> wrote:

> For Pavel's FT8 decoder I can confirm that chan = "2" allows me to use my
> 6 meter antenna for my 6 meter spots and chan = "1" is used for all other
> frequencies with my multi band vertical
>
> Modifying start.sh does not work.
>
> Lee
> ----- Original Message -----
> From: Björn Ekelund <bjorn at ekelund.nu>
> To: Bob Wilson, N6TV <n6tv at arrl.net>
> Cc: SkimmerTalk Reflector <skimmertalk at contesting.com>
> Sent: Fri, 19 Jul 2019 13:03:36 -0600 (MDT)
> Subject: Re: [Skimmertalk] Difference of RP10 14 16
>
> Bob,
>
> I believe my concept for cycling control scripts for Pavel's FT8 decoder
> actually allows you to use
> different antenna inputs for different bands. Without modifying start.sh.
>
> Each line in the files write-c2-files-*.cfg specifies which antenna input
> is used for the sample collection.
> I have not mentioned this in my write up since i have not tried it myself.
>
> ...
>   { freq  =  7.075500; chan = 1; },
> ...
>
> 73,
>
> Björn
>
> Den tors 18 juli 2019 kl 09:27 skrev Bob Wilson, N6TV <n6tv at arrl.net>:
>
> > Are you using a pre-amp?  Does it cover 6m?  My CliftonLabs does not.
> >
> > The SM7IUN scripts rotate the bands for day/twilight/night, but not the
> > antenna assignments.  It sounds like you have a workaround for that.  If
> > you make the last receiver of the eight in all three .cfg files always be
> > 6m, then it should work and always use antenna port 2 if using the
> start.sh
> > described in your post.
> >
> > 73,
> > Bob, N6TV
> >
> > On Thu, Jul 18, 2019, 12:10 AM Lee Sawkins <ve7cc at shaw.ca> wrote:
> >
> >> Bob
> >>
> >> Splitting the signal before the pre-amp is a bad idea.  It costs you at
> >> least 3.5 dB of s/n on all signals.
> >>
> >> I am using an RP-14 for 8 bands of FT8 skimming.
> >>
> >> As per your instructions I set 6 meters to Antenna "2" and the other 7
> >> bands to "1" in "sdr_receiver_hpsdr/start.sh" "1 1 1 1 1 1 1 2 &"
> >>
> >> All bands except 6 meters have spotted FT8 stations.  There has been
> >> activity on 6.
> >>
> >> After not receiving any 6 meter spots I took another very careful look
> at
> >> the setup info at https://sm7iun.ekelund.nu/red-pitaya/ft8-skimmer
> >>
> >> "You may also want to modify the band selection for the three daylight
> >> periods. This is done by commenting/uncommenting the corresponding
> lines.
> >> If you do this, make sure you activate exactly eight bands and also
> keep an
> >> eye on the commas for correct syntax. The number after "chan ="  is the
> >> input used for that frequency. The receiver thus supports the use of two
> >> different antennas."
> >>
> >> My understanding from this is that you can select which antennas you
> >> want, either "1" or "2" for each band for each time period.  I am using
> an
> >> RP-14 with 8 bands selected.  I have now selected "chan = "2" for only 6
> >> meters for all 3 time periods.  The other bands all use antenna = "1".
> >> Unfortunately 6 is dead right now.  Tomorrow I will hopefully see
> whether
> >> this works for 6.
> >>
> >> There is no mention of using "sdr_receiver_hpsdr/start.sh" for antenna
> >> selection in the write up.
> >>
> >> Lee
> >>
> >> ----- Original Message -----
> >> From: Bob Wilson, N6TV <n6tv at arrl.net>
> >> To: SkimmerTalk Reflector <skimmertalk at contesting.com>
> >> Sent: Wed, 17 Jul 2019 11:08:42 -0600 (MDT)
> >> Subject: Re: [Skimmertalk] Difference of RP10 14 16
> >>
> >> On Tue, Jul 16, 2019 at 4:07 PM Lee Sawkins <ve7cc at shaw.ca> wrote:
> >>
> >> > It's a trade off for me. Sensitivity on high bands with a 20 dB
> pre-amp
> >> or
> >> > a few busted calls on lower bands.
> >> >
> >>
> >> Well, since the RP has two antenna inputs, one can assign the low band
> >> slices to antenna input 1 (no preamp), and the high band slices to
> input 2
> >> (with preamp).  If using one common antenna, use a splitter:
> >>
> >>                                                    +------------> Input1
> >> (Low Bands)
> >> Antenna -> Front End Protector -> Passive Splitter +
> >>                                                    +-> Pre-amp -> Input2
> >> (High Bands)
> >>
> >> A passive attenuator in the low band input could also achieve the same
> >> result.
> >>
> >> Antenna assignments for all 16 receiver slices are defined in
> >> *sdr_receiver_hpsdr/start.sh*, and are independent, but not dynamic, so
> >> this works best with no .ini file rotation in Aggregator.
> >>
> >> 73,
> >> Bob, N6TV
> >>
> >> _______________________________________________
> > Skimmertalk mailing list
> > Skimmertalk at contesting.com
> > http://lists.contesting.com/mailman/listinfo/skimmertalk
> >
>
>