HF Beacons and the Reverse Beacon Network, 2017

Below is  a table of the twenty fixed-frequency stations most often posted by the RBN in 2017.

Position Station Frequency (kHz) Number of Posts
1 W0ERE/B 10129 57,379
2 AA1K 1821 55,549
3 HB4FV/B 10134 53,240
4 4U1UN 14100 52,603
5 W6WX 14100 50,622
6 I1MMR 7026 50,212
7 N4BP 14022 43,144
8 EW7LO 7008 42,805
9 4X6TU 14100 41,937
10 4X6TU 18110 38,256
11 IT9SSI 14030 32,998
12 YV5DRN 7011 31,958
13 EA9HU 14016 30,811
14 4X6TU 21150 29,781
15 OK0EV 1854 29,459
16 RR9O 14100 29,328
17 DJ6UX 7039 29,114
18 YV5B 14100 27,900
19 CS3B 14100 26,682
20 KH6RS 14100 26,590

  1. Frequencies are rounded to the nearest kHz;
  2. I am unsure how the U.S. stations in the list can be legal, since the FCC's regulations appear to limit [unattended] HF beacons to a portion of 10m;
  3. FCC regulations also appear to disallow the use of the "/B" indicator as used by station number 1, as the B series is allocated to China.
  4. It is my memory that the original HF beacons were all located on 28 MHz, so that listeners could be made aware of an opening. It is noticeable that not a single one of the stations on the list above is on 10m: the vast majority are on bands that can reasonably be expected to support some kind of non-local propagation at almost all times (which is probably the very reason that they are posted by the RBN so often -- but one does wonder what the putative purpose of such a beacon is);
Below are figures showing, for each of the stations in the table above, the signal strength as reported by the ten RBN stations that most frequently posted each individual beacon station.

In the following figures:
  1. The ordinate for each of the strip charts ranges between 0 dB and the value shown as FSD (i.e., full scale deflection) near the bottom right-hand corner; in this case, the maximum value of each strip is therefore 80 dB.
  2. The value plotted in this manner is the value denoted SNR by the RBN.  Remember that the RBN has an odd definition of SNR.
  3. The abscissa is divided into a number of bins of equal duration. On each plot there are 100 such bins; because the duration covered by each plot is one year, each bin therefore covers about 3½ days.
  4. At the bottom of each strip chart is a coloured bar. Each bin in these bars is coloured so as to represent the total number of times that the RBN station spotted the beacon in the period covered by the bin.The colour legend for each figure is to the right of the figure.
  5. For the period covered by each 3½-day bin, the lower quartile of SNR readings is coloured grey, the upper quartile is coloured white, and the middle two quartiles are coloured blue.
  6. The vertical order of the various RBN stations is determined solely by the chronological order in which each station first spotted the beacon.

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