2017-05-22

Monitoring of HF Beacons by the Reverse Beacon Network: One-Year Spans

I previously posted graphs showing the signal strengths of the most-frequently-reported signals from HF beacon stations, covering the period from the inception of the Reverse Beacon Network ("RBN") in 2009 to the end of 2016.

Naturally, similar plots can be created for arbitrary periods, and such plots might contain interesting features other those on the long-term plots. Here I show plots covering 2016; similar annual plots covering the entire period from 2009 to 2016 are available here (the file has the MD5 checksum d868a05ff2945c0eefe81b68f1d0c301).

As before, each point on the plots covers one one-hundredth of the total span, or, in this case, roughly three and a half days. Also as before, for the period covered by each plot we first determine what qualifies as one of the top twenty beacons reported by the RBN, and, then for each such beacon, which ten RBN posting stations have spotted the beacon the largest number of times  over the duration of the plot.

I repeat the description from my prior post, with suitable emendations consistent with the change in domain:

  1. Every spot by each of the ten RBN stations is plotted with a small open white circle (for the most part the individual circles aren't very obvious, as they overlap so much);
  2. 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.
  3. The value plotted in this manner is the value denoted SNR by the RBN.  Remember that the RBN has an odd definition of SNR.
  4. The abscissa is divided into a number of bins of equal duration. In the plots on this page there are 100 such bins; because the duration covered by each plot is one year, each bin therefore covers about three and a half days.
  5. At the bottom of each strip chart is a coloured bar. Each bin 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
  6. For the period covered by each bin, a small purple rectangle represents the median value of the SNR over the duration of the bin.
  7. Also for the period covered by each bin, the inter-quartile range of the SNR at each RBN station is indicated by a short vertical blue line.
  8. The vertical order of the various RBN stations is determined solely by the chronological order in which each station first spotted the beacon.




















As before, I note:
  1. Frequencies are rounded to the nearest kHz;
  2. The two graphs for I1MMR represent reception of a single station, which appears to transmit on 7026.5 kHz;
  3. I am unsure how the U.S. stations in the list can be legal, at least to the extent that the transmissions were unattended, as §97.203 of the FCC's regulations appear to limit unattended CW HF beacons to a portion of 10m;
  4. §97.119 of the FCC regulations appear to disallow the use of the "/B" indicator as used by the station signing W0ERE/B, as the B series is allocated to China.
  5. 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).

2017-05-19

Call Busts and Reverse Busts in CQ WW, 2015

This is the eleventh in a series of posts on busts and reverse busts in the CQ WW contests. These posts are based on the augmented versions of the CQ WW public logs.

Prior posts in the series:

2015 SSB -- Most Busts
Position Call QSOs Busts % Busts
1 PJ2T 13,766 223 1.6
2 A71CV 10,856 216 2.0
3 CN2AA 24,526 210 0.9
4 ED9K 9,315 205 2.2
5 LZ9W 11,829 199 1.7
6 CN3A 14,494 181 1.2
7 A73A 9,496 181 1.9
8 HK1NA 14,278169 1.2
9 C37N 11,139 152 1.4
10 ZW5B 10,222 150 1.5


2015 SSB -- Most Reverse Busts
Position Call QSOs Reverse Busts % Reverse Busts
1 DF0HQ 13,221 329 2.5
2 9A1A 13,967 243 1.7
3 CN2AA 24,526 224 0.9
4 A71CV 10,856 219 2.0
5 YM7KA 3,113 215 6.9
6 W3LPL 10,344 204 2.0
7 CN2R 14,467 181 1.3
8 WE3C 8,599173 2.0
9 J42T 8,957 160 1.8
10 JA3YBK 7,984 147 1.8


2015 SSB -- Highest Percentage of Busts (≥100 QSOs)
Position Call QSOs % Busts
1 PU2PSP 105 23.8
2 PV8ADI 134 17.2
3 K2JMY 479 16.1
4 4Z5FW 128 14.8
5 UD3D 132 14.4
6 BH4OUF 119 14.3
7 EA1HTF 267 14.2
8 UR5WT 12814.1
9 KB0QEF 105 13.3
10 TA2AET 114 13.2


2015 SSB -- Highest Percentage of Reverse Busts (≥100 QSOs)
Position Call QSOs % Reverse Busts
1 BH2RO 120 12.5
2 9A7JZC 110 10.0
3 PU2UAF 959 9.1
4 VE3LJQ 172 8.7
5 OM7SR 128 8.6
6 K9SOU 107 8.4
7 ZP6DYA 1,408 8.3
8 W8WDW 1128.0
9 BD4KM 128 7.8
10 K4GOP 104 7.7



2015 CW -- Most Busts
Position Call QSOs Busts % Busts
1 PV8ADI 1,346 166 12.3
2 RW0A 8,941 157 1.8
3 NP2P 4,234 156 3.7
4 EF8U 8,774 149 1.7
5 PJ2T 13,055 142 1.1
6 4Z5LY 2,371 137 5.8
7 PW2D 7,867 134 1.7
8 LZ9W 12,796133 1.0
9 G2F 5,471 133 2.4
10 TC0A 10,083 131 1.3


2015 CW -- Most Reverse Busts
Position Call QSOs Reverse Busts % Reverse Busts
1 YT65A 1,394 427 30.6
2 JS3CTQ 3,238 425 13.1
3 DF0HQ 10,922 351 3.2
4 OG55W 930 240 25.8
5 5J1E 2,326 237 10.2
6 ED8X 8,835 231 2.6
7 CR3L 12,414 211 1.7
8 ES9C 8,844211 2.4
9 RM9A 9,798 210 2.1
10 OM2VL 5,078 204 4.0


2015 CW -- Highest Percentage of Busts (≥100 QSOs)
Position Call QSOs % Busts
1 W2UDT 151 23.8
2 F8FHI 124 21.8
3 K8AB 203 21.2
4 YU1NIM 378 20.6
5 AD7XG 176 19.9
6 W1BJ 170 18.8
7 US2MT 124 17.7
8 N1IMW 13917.3
9 AE3D 250 16.8
10 SP5BB 105 15.2


2015 CW -- Highest Percentage of Reverse Busts (≥100 QSOs)
Position Call QSOs % Reverse Busts
1 YT65A 1,394 30.6
2 OG55W 930 25.8
3 PD5JFK 174 24.1
4 BY7KTO 525 22.9
5 W7UDH 129 16.3
6 HB9TXE 177 13.6
7 JS3CTQ 3,238 13.1
8 KB9FBI 10112.9
9 F8CRH 1,138 11.2
10 9A5IP 100 11.0



2017-05-15

Per-Band Plots of the Reverse Beacon Network G(15, 100) Scatter Metric

I recently defined a simple grid-based scatter metric, G(15, 100), for the Reverse Beacon Network (RBN).  Here I show plots of this metric, including frequency information.

I note that a reasonable a priori case can be made on the basis of propagation characteristics that somewhat different metrics in the G(Δ, n) series might be better representations of RBN coverage on some of the bands. However, rather than make this into a full-scale research project, I shall simply use the G(15, 100) metric on the basis that it seems "good enough" on all bands.

RBN Posting Stations as a Function of Time


We begin by looking simply at how the number of per-band posters to the RBN has varied since the RBN's inception. (NB Throughout this post, we ignore posters for which the location is not recorded by the RBN; plots for which the abscissa is time show one datum per month.)

First, a plot of the total number of posters as a function of time:
Now similar plots for the HF bands (in this post I exclude 60m, but include the low bands even though 160m is not technically HF).

10m:

12m:

15m:

17m:

20m:

30m:

40m:

80m:

160m:

These can usefully be represented on a single summary plot that preserves the interesting features of the above graphs:


G(15, 100) as a Function of Time


Turning now to the mensal values of G(15, 100), we obtain the following plots. First, the value covering posters from all bands:

And for the individual bands, starting with 10m:

12m:

 15m:

17m:

20m:

30m:

40m:

80m:

160m:

As before, a summary plot is useful (if only for making it depressingly obvious how much room remains for improvement in coverage):

G(15, 100) as a Function of the Number of Posters


Finally, we can combine the mensal values of G(15, 100) and the number of posters. Firstly, including all bands:

And for individual bands, starting with 10m:

12m:

15m:

 17m:

 20m:

 30m:

40m:

80m:

160m:

The summary plot for these data is slightly different, as the ordinate is multi-valued for some values of the abscissa. So, in this summary plot, we take the mean value of G(15, 100) in bins of width equivalent to ten posters, and plot rectangles in the equivalent colours: