Sunday, October 22, 2017

RBN Developments October 2017

Recently a friend suggested that FT8 was probably making a dent in
activity on the RBN and taking away from CW in general.  Out of
curiosity, I compared last week on the RBN (weekdays only, to avoid
contest activity) with the corresponding week in 2016, and was pleased
to see that the volume of RBN spots in 2017 was up about 8.4 percent
compared to the corresponding week in 2016.

Maybe growth would have been stronger if FT8 and WSPR had not been
introduced, but for a mature system near the bottom of the sunspot cycle
I think the continued upward trend is encouraging. The same week in 2016
was down 12.1 percent compared to 2015, which looks more like what I
would have expected this year.


I don't want to suggest that this is the last word.  I did not take into consideration 
the fact that the number of regularly-active RBN nodes increased year over
year during those two years.A much more accurate metric would to count the 
number of unique CQs reported by the RBN; I didn't do that.  Bottom line, though - 
the RBN is pretty healthy.

Looking ahead to the big DX contest weekends, Felipe made a change in
the data flow at our server this week to sharply reduce the number of
operations that need to take place after spots are received from RBN
nodes and before each individual spot is sent out. We are hopeful this
will improve the server's reliability and handling of large volumes of
spots, as well as reducing the delay in their being posted on retail
servers around the world.


Feedback would be appreciated. ARRL CW Sweepstakes will probably be the
first major test.


5 comments:

  1. Any plans to include FT8?
    Would be helpful!
    de WK2S

    ReplyDelete
    Replies
    1. The problem is that there is no multi-band FT8 receiver/decoder analogous to the CW Skimmer/Skimmer Server family. On any given band, the FT8 op can see all the activity in the FT8 window.

      Delete
    2. Hi Pete,

      This isn't completely true anymore.

      Pavel has a dedicated WSPR application that will skimm all bands from the Red Pitaya and automatically report spots.

      http://pavel-demin.github.io/red-pitaya-notes/sdr-transceiver-wspr/


      73's 9V1RM

      Delete
    3. We're very impressed with Pavel's work. His 8-band receiver is now our standard for use of the Red Pitaya with the RBN.

      FT8 poses a un ique set of challenges for the RBN. VE7CC tried picking up FT8 spots from PSK reporter, and found the volume overwhelming. We're experimenting with an approach that uses WSJT-X in conjunction with the Aggregator, to apply the same rules used for CW and RTTY spots on the RBN - that is, only CQ spots, and respotting stations on the same frequency only once every 10 minutes.

      What we don't have is an 8-band receiver application, so I'm going to write to Pavel and see whether he can modify his 8-band WSPRnet receiver code to fit.

      Delete
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    ReplyDelete