CQWW CW Stats fron N6TV

2012 CQ World-Wide DX Contest

Active Skimmers

Skimmer       Spots    Mean S/N
---------   -------    --------
K3MM-#       157121        41.4
GW8IZR-#     106272        38.9
DR1A-#       100262        51.7
S52AW-#       94954        36.2
DL8LAS-#      87896        38.8
OL5Q-#        85664        44.7
HA6PX-#       75757        40.5
S50ARX-#      72642        46.0
RU9CZD-#      72096        41.2
ES5PC-#       68906        43.5
W3LPL-#       65997        57.2
EI6BT-#       64470        42.0
EA4TX-#       61789        36.9
DJ3AK-#       59490        33.5
LA5EKA-#      59314        54.8
G0KTN-#       58593        36.4
DL1EMY-#      55146        39.3
F4EGZ-#       54657        38.0
DF7GB-#       53099        38.0
KB9AMG-#      51587        39.3
W3OA-#        51326        55.4
ZL2HAM-#      49943        30.6
PJ2T-#        48625        33.4
SV8RV-#       47829        32.4
KQ8M-#        47715        65.0
AA4VV-#       45181        36.0
TF4M-#        44392        54.1
DK9IP-2-#     43828        34.3
OH6RE-#       43409        43.8
WA7LNW-#      43023        62.6
N7TR-#        41594        49.8
NY3A-#        40352        42.2
RN3A-#        40199        33.9
TF3Y-#        40163        37.5
Z38N-#        39871        31.9
KM3T-#        37749        36.3
RN4WA-#       35838        32.6
K3LR-#        35153        66.0
DK9IP-#       32831        32.7
RZ3DVP-#      32754        32.3
V51YJ-#       32448        51.2
WE4S-#        32265        39.2
N6TV-#        31572        29.4
N6WIN-#       30431        67.8
G4HSO-#       30337        33.9
KH6LC-#       30330        29.2
W4AX-#        29587        51.9
PA1T-#        27569        53.6
NC7J-#        26929        29.1
N0TA-#        26546        26.4
EA1FAQ-#      24923        69.3
JK4USW-#      24193        39.3
W8WTS-#       23239        53.6
VE2WU-#       20798        46.7
F5MUX-#       20229        42.7
W4KAZ-#       19976        37.0
G4HYG-#       19675        33.6
UT2UU-#       19574        38.4
9V1RM-#       18733        50.9
5B4AGN-#      18584        33.5
ZL2RV-#       17571        24.5
ON5KQ-#       17212        43.7
JA4ZRK-#      15291        33.9
K1TTT-#       15010        63.8
K9QC-#        14358        62.6
OE3DIA-#      13824        45.1
N4ZR-#        13505        30.2
JG1VGX-#      12094        22.8
N6NC-#        11513        47.1
MM1PTT/P-#    10381        28.5
JJ0PJY-#       9586        38.4
NU6O-#         7665        64.2
PA0MBO-#       7146        27.0
VE6WZ-#        6984        44.9
KA9SWE-#       6887        61.5
W2RDX-#        6869        37.1
N2QT-#         6810        47.0
EI6IZ-#        6563        40.8
NQ6N-#         6219        28.8
DJ4DI-#        6055        39.8
G0VXE-#        5264        42.7
K1FC-#         5027        34.8
K0FTC-#        4984        35.1
WZ7I-#         4847        41.5
IK3STG-#       4530        44.7
OZ5W-#         4448        42.7
PY3OL-#        4333        52.3
W0QL-#         4232        54.9
G6T-#          4173        71.0
WB2LSI-#       3778        32.9
NE5S-#         3731        40.1
DJ9IE-#        3701        45.1
N4BAF-#        3462        46.3
KQ8M-98-#      2965        24.7
AI4HH-#        2952        50.9
W2MKM-#        2717        42.3
M0BPQ-#        2501        22.2
DF6PW-#        2395        38.6
AB7TB-#        2381        30.1
VA6DBA-#       1814        34.8
R4WT-#         1367        33.7
SV9/IV3NOB-#   1336        36.8
G6LSB-#        1220        29.5
DO6NIK-#        901        74.5
PY1KN-#         845        20.2
DJ2RD-#         813        63.1
SK3W-#          744        44.5
VU2LBW-#        649        15.3
NP2L-#          600        32.3
LY2XW-#         394        27.8
MM0SAJ-#        358        63.6
DK1MAX-#        349        38.2
DL5KW-#         341        42.3
K2NNY-#         276        23.8
DL1AMQ-#        269        41.6
WB8BIL-#        240        29.0
IK0XBX-#        162        78.8
DO4DXA-#        160        44.2
DL4RCK-#        149        30.8
KS4XQ-#         130        70.7
PP5MCB-#        112        29.3
VK1LW-#          72        15.0
LU1CGB-#         26        18.2
G4MKP-#          25        69.0
N4IS-#           24        37.5
KQ8M-K3-#        17        36.4
KB9VLR-#          7        22.7

2012 CQ World-Wide DX Contest

Most Spotted

Callsign      Spots    Mean S/N
---------   -------    --------
DR1A          24376        57.2
9A1A          23096        48.5
K3LR          22638        54.2
NQ4I          20537        47.0
W3LPL         19851        54.0
DF0HQ         18743        55.0
LZ9W          17251        54.8
Z38N          16111        46.8
HK1NA         15299        55.7
HG1S          14613        50.9
C5A           14274        59.0
N3RS          13535        55.7
LY7A          13377        39.2
F6KOP         12899        52.8
OZ5E          12156        50.2
II1A          11767        48.4
VE3EJ         11732        57.9
EA2EA         10426        56.4
DR5N          10083        57.8
W0AIH          9906        38.2
YT2W           9676        49.6
D4C            9255        61.3
NY4A           9225        50.5
KB1H           9173        49.2
K2LE           9121        37.2
JA5FDJ         9070        48.6
WT1T           8738        58.5
K8AZ           8703        57.7
K0RF           8664        38.6
LZ5R           8656        45.1
9A7A           8599        49.1
N4WW           8536        42.2
PI4CC          8478        53.4
JA3YBK         8471        55.8
DR4A           8389        56.9
OH0V           8289        45.6
LY2W           8037        51.5
TC2M           7747        43.0
IR4M           7736        48.7
AD4Z           7731        42.8
W3EA           7716        46.6
PJ2T           7708        61.7
PJ4A           7661        49.4
HB9CA          7554        55.4
KH6LC          7366        57.7
RT6A           7363        50.6
CR3L           7082        52.5
S50G           6964        60.8
W3UA           6842        46.4
NR4M           6823        37.1


Most Spotted Callsigns

     World-Wide    
Call          Spots
---------   -------
DR1A          24376
9A1A          23096
K3LR          22638
NQ4I          20537
W3LPL         19851
DF0HQ         18743
LZ9W          17251
Z38N          16111
HK1NA         15299
HG1S          14613
C5A           14274
N3RS          13535
LY7A          13377
F6KOP         12899
OZ5E          12156
II1A          11767
VE3EJ         11732
EA2EA         10426
DR5N          10083
W0AIH          9906

               160m
Callsign      Spots  Pk. S/N  Med. S/N  Mean S/N
--------      -----  -------  --------  --------
DR1A           3565       80      25.0      46.5
9A1A           3223       83      26.0      50.6
S51V           3060       62      26.0      42.1
LN9Z           3004       54      24.0      35.7
LY7M           2982       74      23.0      42.8
S52X           2949       92      21.0      60.4
LZ9W           2892       58      20.0      35.4
HA8BE          2536       58      20.0      34.0
M5O            2364       59      23.0      39.4
LY7A           2292       58      18.0      34.3
HG5A           2252       58      18.0      33.2
Z38N           2132       56      18.0      30.7
DF0HQ          1919       58      25.0      37.3
OZ5E           1914       69      20.0      38.1
HG1S           1737       55      21.0      36.2
EF8S           1678       82      16.0      55.1
F6KOP          1588       87      20.0      57.7
GM4AFF         1507       42      17.0      24.3
UY0ZG          1490       73      15.0      41.9
F5IN           1482       60      24.0      35.7

                80m
Callsign      Spots  Pk. S/N  Med. S/N  Mean S/N
--------      -----  -------  --------  --------
DR1A           5010       89      31.0      53.5
OL8M           4663       98      34.0      62.0
9A1A           4482       83      35.0      50.7
DJ0MDR         4155       71      35.0      46.3
K3LR           4132       85      25.0      49.2
DF0HQ          3931       89      33.0      55.9
DM7C           3906       85      27.0      51.5
DL7ON          3893       78      27.0      44.4
9A2U           3863       82      33.0      47.6
W3LPL          3665       94      26.0      60.5
NQ4I           3442       87      25.0      52.1
LZ9W           3359       94      32.0      59.8
LY7A           3358       60      26.0      39.0
W1MK           3285       77      23.0      42.2
Z38N           3208       58      30.0      38.9
OZ5E           3090       89      27.0      55.1
S52ZW          3051       95      32.0      60.3
HG1S           2918       89      28.0      54.6
II1A           2884       88      33.0      54.0
OK2BYW         2773       87      31.0      53.2

                40m
Callsign      Spots  Pk. S/N  Med. S/N  Mean S/N
--------      -----  -------  --------  --------
DR1A           8115       78      26.0      48.3
LZ9W           7398       92      28.0      54.1
K3LR           7354       86      24.0      47.7
9A1A           7283       81      27.0      46.5
DF0HQ          6813       96      23.0      57.8
NQ4I           6705       66      25.0      45.0
YU1LA          6447       95      31.0      58.9
IH9R           6309       76      26.0      40.7
W3LPL          6297       74      23.0      39.3
S57Z           6193       87      24.0      52.0
Z38N           6010       86      24.0      50.6
S56X           5875       95      24.0      58.3
N3RS           5688       93      21.0      55.6
HG1S           5015       86      25.0      52.3
DL3VZL         4975       97      25.0      61.2
IR2R           4927       94      23.0      59.7
S52AW          4894       89      27.0      54.8
C6AKQ          4886       94      25.0      57.2
YT7A           4672       95      24.0      59.2
II1A           4627       60      21.0      36.6

                20m
Callsign      Spots  Pk. S/N  Med. S/N  Mean S/N
--------      -----  -------  --------  --------
K3LR           5145       69      21.0      38.6
NQ4I           5063       70      22.0      46.2
C5A            4719       67      19.0      33.4
W3LPL          4660       83      22.0      50.5
9A1A           4582       80      26.0      47.7
HK1NA          4513       81      24.0      45.6
TM5Y           4407       70      26.0      43.9
DR1A           4354       99      25.0      64.0
HA8IH          4292       71      25.0      45.7
N5NU           3688       69      23.0      47.7
OK7M           3651       87      22.0      57.9
N2MF           3492       76      23.0      42.8
OH8L           3428       85      26.0      50.3
SN5W           3416       81      25.0      47.1
OL9Z           3353       66      23.0      43.4
OK7K           3117       75      25.0      49.5
LY7A           3110       76      25.0      43.1
KU5B           3085       78      25.0      47.7
HG1S           3040       77      23.0      44.7
WT1T           3002       70      23.0      39.4

                15m
Callsign      Spots  Pk. S/N  Med. S/N  Mean S/N
--------      -----  -------  --------  --------
C5A            2954      100      22.0      65.3
D4C            2921       78      21.0      43.7
K3LR           2920       59      21.0      36.3
NQ4I           2868       58      19.0      35.3
FY5KE          2673       90      24.0      56.5
TM6M           2640       96      21.0      63.3
ZW5B           2633       84      21.0      51.0
HK1NA          2465       74      23.0      41.6
W3LPL          2442       65      24.0      42.2
9A1A           2365       79      20.0      47.1
CS2C           2359       77      28.0      46.8
9A5D           2245       82      19.0      49.1
EA2EA          2199       64      21.0      38.5
OK8WW          2101       89      21.0      56.1
DF0HQ          2086       84      21.0      52.0
VE3EJ          2080       59      22.0      34.8
W0AIH          2043       64      21.0      38.0
PJ4A           2040       55      22.0      34.5
S57C           2031       74      21.0      46.2
9A1CCY         2012       88      20.0      55.8

                10m
Callsign      Spots  Pk. S/N  Med. S/N  Mean S/N
--------      -----  -------  --------  --------
K3LR           1711       69      18.0      46.4
PY3DX          1597       64      18.0      35.2
PT2CM          1525       71      17.0      39.5
HK1NA          1521       62      23.0      37.1
NQ4I           1378       57      14.0      35.7
W3LPL          1375       65      22.0      43.1
DR1A           1375       78      15.0      47.0
C5A            1238       71      22.0      43.8
W4ZV           1222       74      18.0      44.2
K2SSS          1212       50      16.0      32.3
EA8CN          1199       69      20.0      39.0
LP1H           1188       68      20.0      38.1
9A1A           1161       71      15.0      42.9
LT1F           1119       48      20.0      29.2
4Z5LA          1088       54      18.0      32.4
PJ2T           1077       75      22.0      45.3
CE2AWW         1075       81      15.0      51.0
CX7CO          1066       85      15.0      55.4
N5XJ           1059       81      17.0      50.9
9A4M           1034       88      16.0      57.9



   North America   
Call          Spots
---------   -------
K3LR          22638
NQ4I          20537
W3LPL         19851
N3RS          13535
VE3EJ         11732
W0AIH          9906
NY4A           9225
KB1H           9173
K2LE           9121
WT1T           8738
K8AZ           8703
K0RF           8664
N4WW           8536
AD4Z           7731
W3EA           7716
W3UA           6842
NR4M           6823
VE7FO          6458
K9CT           6065
W8AV           6001

   South America   
Call          Spots
---------   -------
HK1NA         15299
PJ2T           7708
PJ4A           7661
PT2CM          6407
PW7T           5445
YW4D           3877
LT1F           3433
P49Y           3150
LU8YE          3051
PS2T           2983
HD2A           2922
LP1H           2908
PJ4D           2854
PZ5T           2792
FY5KE          2673
P40W           2650
ZW5B           2633
PR5B           2177
HK3O           2107
CW5W           1945

       Europe      
Call          Spots
---------   -------
DR1A          24376
9A1A          23096
DF0HQ         18743
LZ9W          17251
Z38N          16111
HG1S          14613
LY7A          13377
F6KOP         12899
OZ5E          12156
II1A          11767
EA2EA         10426
DR5N          10083
YT2W           9676
LZ5R           8656
9A7A           8599
PI4CC          8478
DR4A           8389
OH0V           8289
LY2W           8037
IR4M           7736

       Africa      
Call          Spots
---------   -------
C5A           14274
D4C            9255
CR3L           7082
IH9R           6310
EF8M           4534
6V7V           3201
EF8X           3126
ZD8W           2115
ZS4TX          1941
EL2A           1940
CR3E           1936
EF8S           1680
EA8CUU         1616
5X1NH          1455
5C5W           1332
ZS2I           1235
EA8CN          1205
EF8U           1153
ED9Z           1143
5H3EE          1128

        Asia       
Call          Spots
---------   -------
JA5FDJ         9070
JA3YBK         8471
TC2M           7747
UP0L           4668
RG9A           4418
R9DX           4399
JA1YPA         3560
RW0A           3265
B1Z            3062
4X/UA9CTT      2904
UP2L           2645
RT9A           2638
JH4UYB         2617
JH1GBZ         2546
JA0QNJ         2452
P33W           2445
UN9L           2417
7J1YAJ         2377
RT0C           2303
JS3CTQ         2257

      Oceania      
Call          Spots
---------   -------
KH6LC          7366
KH7X           5946
ZM1A           4187
ZM4T           3768
VK4CT          2607
AH2R           1889
KH7M           1592
KH6MB          1510
VK6LW          1490
NH2T           1466
AH0DX          1429
9M6NA          1293
YE1C           1252
VK2IM          1011
YE2W            943
VK3TDX          849
KH2/JK2VOC      745
VK8GM           659
YB4IR           565
9M6YBG          565

Where to Find RBN Spots

For a while now, we have been encouraging users to get their RBN spots from AR Cluster V6 and VE7CC clusters, rather than directly from the RBN's own Telnet servers.  The idea is to protect them from excessive loading.

For anyone who's wondering how to find which clusters are running which software, This web site has excellent listings.

73, Pete N4ZR

Setting Up for CQWW CW

Looking ahead just a few days to the CQWW CW contest, don't forget to open up your CW Skimmer/Skimmer Server CW Segments to cover whatever bandwidth your computer can handle. 

The solution is in the CW Segments line of your SkimSrv.ini file.  As it comes from VE3NEA it reads:

CwSegments=1800000-1840000,3500000-3570000,7000000-7035000,7045000-7070000,
10100000-10130000,14000000-14070000,18068000-18095000,21000000-21070000,
24890000-24920000,28000000-28070000,50000000-50100000

Note, for example, that with these settings it won't decode anything above 14070 or between 7035 and 7045. The "factory" settings are intended to eliminate "false decodes" from RTTY and PSK signals, but there won't be much of that on the bands this weekend. If you leave it as is, you'll miss a lot of the CW activity in the contest.

The solution is pretty simple - set each segment to be continuous and cover the entire CW band (or as much as you can).  For example, make 10M 28000000-28200000 and 20M 14000000-14100000, so even if you use 192-KHz coverage, there will be no "dead zones."

See you on the RBN this weekend!

73, Pete N4ZR

New Features in Aggregator 2.3, now on the web site

W3OA has released Aggregator 2.3, after a series of beta tests.  It has a number of new features that will be of interest, particularly as we begin also providing digital spots from stations using DL4RCK's RCKskimmer.  The new release is now on the web site, under Downloads.

The big change in the new Aggregator is the addition of a new Combine Skimmers tab, illustrated below:





As usual with Dick's programming, the new tab is self-explanatory.  It will take a stream of combined Skimmer spots from multiple Skimmers, coming from wintelnetX or AR Cluster Serve,r and feed them to the "mother ship" under a single callsign, substituting what you fill in here for the information normally provided separately by each instance of CW Skimmer or Skimmer Server.

The other big change is that Aggregator 2.3 now supports RCKskimmer by DL4RCK for digital modes by accepting mode and speed information from it and forwarding the information to the server.  From there spots, in a new format are distributed via our two Telnet servers.  They look like this:

DX de KM3T-#:    21016.5  SM7YIN         CW    09 dB  25 WPM  CQ      1233Z
DX de EA4TX-#:   21016.6  SM7YIN         CW    22 dB  25 WPM  CQ      1233Z
DX de KQ8M-2-#:  21071.4  RA3PS          BPSK  08 dB  31 BPS  CQ      1233Z
DX de LA5EKA-#:  14028.1  OZ3NP          CW    11 dB  22 WPM  CQ      1233Z

The format is compatible with all standard DX clusters, since all of the data - from mode through CQing status - is contained in the Comment field size set by the basic spot format.

It is our intention to support any further digital Skimmers that emerge, so long as they deliver their spots by Telnet and their output conforms with that provided by CW Skimmer, Skimmer Server and RCKSkimmer.

We urge all Skimmer operators to update to Aggregator 2.3 as soon as possible.

73, The RBN Development Team

Aggregator 2.2 Released

Dick, W3OA has released the latest Aggregator after a substantial period of beta testing.  Let's have a look at the key new features, and then I'll show you some screenshots.

• The Status tab now includes information for the individual Aggregator op about how accurate the frequency of his spots is currently, as measured against both fixed and dynamic standards on each band.  Note, this is not foolproof.  For example if a CQing station QSYs a short distance and calls CQ again, the Aggregator may temporarily report  a big skew (our term for a frequency discrepancy).  Skew figures are recalculated and sent to each user every 5 minutes, so if you see one that is surprising, just wait 5 minutes and see if it disappears.  With the QS1R receiver, a calibration problem will typically involve excessive skews only on the higher bands, and they will be progressively larger as the frequency increases.  If you think you have a calibration problem, check out this blog post from last year for a quick and easy way to calculate the correction factor to put in your .ini file.
• Operators can now select the port number they want for local Telnet connections.
• The Aggregator now shows the validation level set in CW Skimmer or Skimmer Server, and recommends using Normal if not set to Normal.  This is not mandatory, but does help to maximize the number of spots forwarded with seemingly negligible effect on accuracy.
• Popup windows warn the user if the Aggregator can't connect either to the Skimmer or to the RBN Server for 5 minutes.  Another popup will suggest updating if you are not using the latest Aggregator available on the RBN web site.
• VHF+ spots than look like grid squares can now optionally be filtered out rather than being forwarded to the server.
• VHF+ spots with SNRs <+ 1 dB can now be filtered out, to prevent bogus spots of various sorts of spurious signals.

The big changes are summarized on the Status tab:

The red box is just for emphasis, and doesn't actually appear in the Aggregator.  It points out where the frequency calibration summary will be found.

Next up is the Spot Filters tab:

This one is all pretty self-explanatory.  Dick's done a terrific job of making each option pretty self-documenting.  This is where you set up Bad Call lists, useful if RFI in your station causes a lot of false  spots that are corrupted versions of your callsign.  You can also set up a list of Notched Frequencies, and of course the check boxes at the bottom of the page let you set up those lists and then decide whether or not to use them at any particular moment.

And finally, the last tab with changes is the Connections tab:

Again, the red is just for emphasis in this blog.  The rectangle shows much more detail on your frequency calibration, updated every 5 minutes.  The ellipse shows where you can now select the local user port.

So that's the story.  What do you think?

73, Pete N4ZR

About This Project - redux

Recently, I started thinking that I'd better capture some of the history of the RBN before passage of time and an aging memory obscured it forever.  The About This Project section on the RBN website needed updating anyway, so I collected a few key dates from e-mails and Skype logs, and here it is.  I hope you enjoy it.

About This Project

The Reverse Beacon Network was borne out of an e-mail exchange in March of 2008 between PY1NB and N4ZR.  Felipe had been running a unique DXing web site, DXWatch.com, for several years, while Pete had been working with VE3NEA, the author of the CW Skimmer software, since late 2007 to test, develop and refine it.  Felipe saw a way in which the basic framework of DXWatch could be adapted to display Skimmer spots at a central location as “reverse beacons”, spotting everything they heard.  Early in April, Felipe wrote the first Aggregator software, intended to receive spots from Skimmer’s Telnet server and transmit them to the web site for display.

The web site was initially the only way to view Skimmer spots. But as the controversy raged in the contesting community over whether unassisted single operators should be allowed to use this new technology, it occurred to the RBN operators that there might be an opportunity here to contribute Skimmer spots to the worldwide contest and DX community through a Telnet server using DX cluster software.  We had no clue how quickly this would change contesting.

It took a while, but in April 2010 the Telnet server debuted.  Almost immediately, it proved very popular, to the point where the server began to buckle under the load of being the only outlet for RBN spots  

At first, there was general consternation at the thought of Skimmer spots being integrated into the traditional DX cluster structure, for fear that their sheer volume would submerge the traditional spots people were used to.  Happily for the RBN, though, writers of cluster software soon recognized that they could accommodate the RBN spots by providing filters to segregate the Skimmer spots if desired.

Meanwhile, Nick, F5VIH/SV3SJ joined the RBN team.  His computer science background was a great asset, and in July 2010, he rolled out the Signal Analysis Tool, a graphical way to compare signals of multiple stations on multiple bands, as heard by a single Skimmer anywhere in the world. 

 

In September 2010, VE7CC and VE1DX began distributing RBN spots through their cluster servers.  Shortly thereafter, AR Cluster Version 6 was released in beta with similar provisions and an advanced filtering scheme. 

 In November, just in time for CQWWCW, Dave, KM3T joined the team.  He, Nick and Felipe worked hard to ensure that the RBN servers would not fail during the contest.  They succeeded, and the Telnet server delivered over 1.7 million spots without incident.  In March of 2011, a second Telnet server running ARC6 was added to the RBN’s facilities, spreading the load and allowing for distribution of Skimmer spots to ARC6 clusters worldwide.

In September 2011, Dick, W3OA joined the team and wrote the first Windows Aggregator.  The beta was a success, and in succeeding months he delivered increasingly sophisticated versions of the software, which is now in release 2.1.  In November 2011, the RBN handled 3.25 million spots during CQWW, an average of 18.9 spots per second, with no problems.

So far in 2012, the RBN’s servers have been handling the load nicely. The  ARRL DX contest, the Russian DX Contest, and WPXCW passed without incident.  In WPX, the RBN actually handled slightly more spots than in last year’s CQWW, which gives us a sense of what to expect next year in CQWW.

Perhaps more importantly for the loading of the system, we topped 100 simultaneous Skimmers during the weekend, and actually had 114 unique Skimmers contribute  during that period.  As far as hardware is concerned, we’re in a period of watchful waiting.  At some point the database server will max out, probably necessitating separating it from the web server, but we seem to have a little way to go yet.  Meanwhile, Nick and Felipe are working on a new set of statistical tools that should enable everyone to get the numbers he needs from the system in near real time.  We’re optimistic that usership will continue to grow.

Stay tuned … who knows when the next good idea will come along?  And if you’d like to join us, drop us an e-mail and tell us what you have in mind.

73, Pete Smith, N4ZR

Some Thoughts on Accuracy

In order to correctly evaluate the accuracy of the RBN versus traditional spotting, I think you need to start with the idea that the RBN is not a traditional spotting network.  Here's what I mean.

Accuracy of a properly set up CW Skimmer in copying callsigns runs right around 99 percent.  There is an as-yet-unresolved problem with copying callers as if they were runners - more on that below.  But let's assume the 99 percent is right for an individual Skimmer, one not assailed by local RFI.

If you consider the RBN, on an open band, with no spot filtering by spotter location, then the picture changes.  Suppose you have 30 Skimmers in zones 4 and 5, all copying an open band.  Each running station will be spotted every 10 minutes by each RBN station, so long as the station remains on its run frequency.  You could, theoretically, have as many as 180 spots of each running station every hour.  In that case, simple probability says there will be roughly 1.8 busted spots per hour of each one.

If you are sitting at a big multi-op, receiving spots from all over the world, or just all over the US, then it is almost inevitable that you will see busted spots a lot more often than from the Cluster network.  Not only are there 10-15 times as many spots, but there will be busts of many running stations, just by the math.  On Sunday, you will see tons of busts, because by that time you will have worked most of the good callsigns, leaving only the busts on your bandmaps.

There are several partial solutions, not all of which will be implementable at a big multi, but let me mention a few:

*  Filter by spotter location, so that you only get spots from stations who are probably hearing the same things as you can.  For example, I filter by spotterstate = MD or PA or VA or NC or WV (have to get my own spots too).  That cuts down the number of Skimmers feeding my bandmap to 7-8, sharply reducing the probability of busts.

*  Use the "Unique > x" filter in AR Cluster version 6.  That filter only passes a spot if at least x+1 Skimmers worldwide have copied the same spot the same way in a relatively short period of time.  This helps a lot to winnow out busts, as you can imagine.  The RBN has a very robust ARC6 node at arcluster.reversebeacon.net, port 7000.

*  Use a logging program that permits displaying unworkable spots (already worked, or not workable in a given contest) on the bandmap.  For example, N1MM Logger displays such spots in gray.  The advantage of doing this is that if LZ9W is running, but you worked him 30 hours ago, and LZ9WL suddenly shows up on the same run frequency, you can see that it's pretty likely to be a bust.  This also helps with callers mistakenly identified as runners; if you see calls appearing one after another on the same frequency as one of the big runners, you're probably safe in skipping past them.

We hope this is helpful.

73, The RBN Team

Aggregator 2.1 - new insight for Skimmer ops

The newest Aggregator, Version 2.1, is now available, after extensive beta testing.  This post explains the new features of this release, tab by tab.

First of all, there is an entirely new tab titled "Skimmer Traffic."  Here's what it looks like:

  Overwhelming, right?  What this does is to keep track of what happens to every spot made by your Skimmer.



The left-hand side of each row is exactly the same as you are used to seeing in the Aggregator, except for the color coding.  Only the green spots are actually sent along to the RBN.

The right-hand side is where the fun stuff is.

For example, take a look at the first green timestamp. The rest of that line (the brown part) tells you how Aggregator decided to send the spot on to the RBN, and what it sent. The first brown entry is the frequency sent to the RBN.  This will be different from the spot frequency on the left if you are using a transverter in front of your SDR and have entered a base frequency to be added to each spot.

Then Skimmer decided that first green spot was a "CQ" spot.  If it had been a VHF spot, Aggregator would have sent it on anyway, but NVHF means it was not. NExcl means that the spot's frequency was not within the excluded frequencies controlled by the server (more on that below), and NBcn means it was not a regular, listed beacon.  Either VHF or Bcn would have over-ridden an NCQ determination, while Excl would have blocked a spot that otherwise seemd to qualify (see below). NInMaster didn't matter, because I had not selected the option to spot only those stations in the master.,scp file, and finally, NInBadCall meant that I had not identified this call as a "badcall", one of those produced by local RFI.

Why bother?  Some RBN Skimmer Ops wanted to be able to see why a given spot was or was not sent to the RBN, or whether their BadCall list was working properly.  This should give them all the information they need.

Reminders about the color-coding and symbols are at the top of the Skimmer Traffic tab.

Some users had expressed a need for a way to notch out specific frequencies, typically on 60 meters, because digital signals on those frequencies were being mis-decoded.  This capability has now been added to the  Spot Filters tab.

On the .ini files tab, Edit buttons have been added for each of the files listed in the two .ini rotations.

There is a new feature in the middle panel of the Connections tab. 



The last check-box allows you to accept or reject a list of excluded frequencies downloaded from the RBN.  Typically, the purpose is to block "spots" of RTTY stations, where Skimmer will attempt to decode Baudot as if it were Morse.  However, during contests you would want to un-check this option, because CW contest activity typically runs into the normal RTTY frequencies and beyond.


In addition, in the Local User area at the bottom, Dick has added two new features on the right side. Port 7550 is now capable of accepting more than one logon at a time, in case several of your friends want to connect locally. 



 The SETT response is what Aggregator uses to tell the RBN server periodically what bands you are listening on.  We thought any local users might want the same information periodically.


That's all for this release.  What would you like to see in the next one?

73, Pete N4ZR