Wednesday, March 7, 2012
What Does a Flare Look Like?
Amazing screenshot from the RBN taken during today's flare. Questions, anyone?
Tuesday, March 6, 2012
All the Details Fit to Print!
There is a new feature on the RBN web site, one intended specifically to help Reverse Beacon operators. If you click on the Skimmers menu on the main page, you'll be given the choice of Simple or Detailed List. If you choose the Simple option, you'll be taken to the same page as before, but with a new link titled "Check here for detailed Skimmers list". Click either "Detailed" link and you'll be taken to a new page that has a lot more information about each Skimmer.
Let's look at an entry:
Now let's break it down. Incidentally, you may have noticed that callsigns move around on the Skimmer list. This is because it is dynamic, based on the most recent spots, to the nearest minute. In effect it looks at the RBN web-site's main page and lists the stations it sees online at that moment.
Next over, the "Skimmer" column displays the release of Skimmer or Skimmer Server being used by the station. Below that is the validation level in use, and below that it reports whether the Skimmer is sending all spots to the Aggregator, or just CQ spots. I'm sending all spots from the Skimmer to the Aggregator, and relying on the Aggregator to forward only CQ spots and regular beacon spots below 50 MHz, and all spots on 50 MHz and above.
The next column reports the Aggregator version in use at the Reverse Beacon station. We're encouraging everyone to be on at least version 2.01, but there are always stragglers. I'm running 2.1 beta 7, which is a new one coming out soon.
Next is the Bands Column. Here are listed the exact bands covered by the RBN station's Skimmer. For technical reasons, a 96-KHz Skimmer bandwidth only produces a maximum of 91 KHz coverage, which is why the odd numbers.
The next column is where it really gets interesting. "Skews" is a term that Felipe PY1NB invented to describe the difference between frequencies being reported by a given Skimmer for a given station, and the frequency reported by a reference station. What's a reference station? Well, we start with two all-band Skimmers, one in Europe and one in the United States, which have well-established frequency calibration. Each time another station and one of these reference stations both make the same spot, the server compares their frequency reports. They don't necessarily have to make the spot at the same time; in fact, if a non-reference station makes a spot, the server will try to validate it for some minutes against another spot of a station, before giving up. And here's the clever part. In addition to the two reference stations, any station that is found to agree with them exactly is named a temporary reference station, and for a substantial period it, too, can serve as a reference. This helps to deal with propagation "holes" that might otherwise prevent validation of spots against one of the two principal reference stations. When a band is open, we typically have 20-30 stations that are temporarily given this status.
So what does the column show? If there is a "0" in the column it means that the RBN station is currently a reference station on that band. If there is a "-", that means that the server has not yet been able to compare that station's spots on that band with one of the reference stations. And finally, if there is a number, like "-0.2", it means that the last spot on that band by that station was off by that amount (in this case, 0.2 KHz low.
Because the DX cluster network only handles frequencies to an accuracy of 0.1 KHz, any station that has either a "0" or a +/- 0.1 entry should consider that its calibration is "right on." Skews of 0.2 or more should probably be dealt with. If you are using a QS1R, you will find that your skews, if any, will increase as you go up in frequency - so a 0.2 skew on 20 meters might be 0.4 on 10.
If you want to correct your calibration, an easy method was explained in a post on this blog in March, 2011. You can read it at http://reversebeacon.blogspot.com/2011_03_01_archive.html
One interesting question that this raises. If a station's calibration is off by a few tenths of a KHz, should the server apply a correction? Opinions welcome!
Let's look at an entry:
Callsign Skimmer Aggregator Bands Skew Began Last Seen
| N4ZR | v.1.30.0.127 normal ALL spots | 2.1b7 | 7000~7070 10100~10130 14000~14091 18068~18095 21000~21091 24890~24920 28000~28091 | 0 0 0 0 0 0.1 - | 3 years ago | online |
Now let's break it down. Incidentally, you may have noticed that callsigns move around on the Skimmer list. This is because it is dynamic, based on the most recent spots, to the nearest minute. In effect it looks at the RBN web-site's main page and lists the stations it sees online at that moment.
Next over, the "Skimmer" column displays the release of Skimmer or Skimmer Server being used by the station. Below that is the validation level in use, and below that it reports whether the Skimmer is sending all spots to the Aggregator, or just CQ spots. I'm sending all spots from the Skimmer to the Aggregator, and relying on the Aggregator to forward only CQ spots and regular beacon spots below 50 MHz, and all spots on 50 MHz and above.
The next column reports the Aggregator version in use at the Reverse Beacon station. We're encouraging everyone to be on at least version 2.01, but there are always stragglers. I'm running 2.1 beta 7, which is a new one coming out soon.
Next is the Bands Column. Here are listed the exact bands covered by the RBN station's Skimmer. For technical reasons, a 96-KHz Skimmer bandwidth only produces a maximum of 91 KHz coverage, which is why the odd numbers.
The next column is where it really gets interesting. "Skews" is a term that Felipe PY1NB invented to describe the difference between frequencies being reported by a given Skimmer for a given station, and the frequency reported by a reference station. What's a reference station? Well, we start with two all-band Skimmers, one in Europe and one in the United States, which have well-established frequency calibration. Each time another station and one of these reference stations both make the same spot, the server compares their frequency reports. They don't necessarily have to make the spot at the same time; in fact, if a non-reference station makes a spot, the server will try to validate it for some minutes against another spot of a station, before giving up. And here's the clever part. In addition to the two reference stations, any station that is found to agree with them exactly is named a temporary reference station, and for a substantial period it, too, can serve as a reference. This helps to deal with propagation "holes" that might otherwise prevent validation of spots against one of the two principal reference stations. When a band is open, we typically have 20-30 stations that are temporarily given this status.
So what does the column show? If there is a "0" in the column it means that the RBN station is currently a reference station on that band. If there is a "-", that means that the server has not yet been able to compare that station's spots on that band with one of the reference stations. And finally, if there is a number, like "-0.2", it means that the last spot on that band by that station was off by that amount (in this case, 0.2 KHz low.
Because the DX cluster network only handles frequencies to an accuracy of 0.1 KHz, any station that has either a "0" or a +/- 0.1 entry should consider that its calibration is "right on." Skews of 0.2 or more should probably be dealt with. If you are using a QS1R, you will find that your skews, if any, will increase as you go up in frequency - so a 0.2 skew on 20 meters might be 0.4 on 10.
If you want to correct your calibration, an easy method was explained in a post on this blog in March, 2011. You can read it at http://reversebeacon.blogspot.com/2011_03_01_archive.html
One interesting question that this raises. If a station's calibration is off by a few tenths of a KHz, should the server apply a correction? Opinions welcome!
Wednesday, February 22, 2012
ARRL DX CW Stats - Thanks, N6TV
2012 ARRL DX CW Active Skimmers Skimmer Spots Avg S/N --------- ------- ------- W3OA-# 83583 27.3 K3MM-# 80937 27.8 KM3T-# 75130 24.1 W3LPL-# 73068 28.0 N4ZR-# 69119 22.5 WA7LNW-# 65423 23.9 S50ARX-# 61431 23.7 K3LR-# 61133 27.7 N7TR-# 58962 24.4 N6TV-# 56188 17.8 DL2CC-# 56170 23.2 GW8IZR-# 54831 25.0 ES5PC-# 53542 23.9 DL8LAS-# 52504 21.6 NC7J-# 52129 19.5 HA6PX-# 51547 22.5 K8ND-# 51508 20.8 DR1A-# 51295 25.1 ON5KQ-# 50112 24.0 G0KTN-# 50090 22.8 DJ3AK-# 48395 19.1 WZ7I-# 47023 30.7 AB1HL-# 46947 23.9 LA5EKA-# 46848 21.8 N0TA-# 45662 18.2 US0KW-# 44895 21.7 DK9IP-# 44084 18.0 OH6BG-# 43181 23.3 OH8WW-# 41376 24.3 W4AX-# 41209 25.1 KB9AMG-# 38492 21.5 OL5Q-# 37218 21.6 KH6LC-# 37212 20.6 PJ2T-# 36623 18.6 G4HSO-# 33996 25.1 KQ8M-# 30960 20.8 W0MU-# 29448 18.4 RU9CZD-# 28996 16.9 TF3Y-# 28615 25.2 RZ3DVP-# 28273 18.2 K1TTT-# 28224 26.6 PA1T-# 28125 19.6 W8WTS-# 26524 21.8 F4EGZ-# 23383 24.2 AJ4MJ-# 21729 21.1 V51YJ-# 20431 15.7 ZL2RV-# 19387 14.6 JA4ZRK-# 18873 21.3 K9QC-# 18371 22.3 VE2WU-# 18308 30.5 N6NC-# 16993 12.5 RN4WA-# 15235 12.0 JH3PRR-# 14704 20.1 N2QT-# 12984 28.1 VK6IA-# 12866 13.0 W1UJ-# 11540 23.7 UA4NE-# 10647 15.8 IK3STG-# 9343 15.7 HB9SOF-# 9138 18.9 SM6FMB-# 8243 19.3 DL0LBS-# 8080 17.2 KS4XQ-# 7919 25.0 JG1VGX-# 7788 15.1 AB7TB-# 7127 18.4 HA1VHF-# 6991 18.6 SE0X-# 6467 25.4 F5VLY-# 6131 29.8 VK1LW-# 5852 11.1 S55OO-# 5483 24.8 PY3OL-# 4063 11.6 W2MKM-# 2825 18.1 DL0TUD-# 2500 25.6 R4WT-# 2263 9.8 SK3W-# 2227 27.1 SA7AKE-# 2028 14.4 DO4DXA-# 1548 16.9 DL1EMY-# 1183 29.2 W0QL-# 1128 18.5 AK2B-# 992 10.7 DJ2RD-# 487 27.0 G4HYG-# 310 14.4 G3UYN-# 216 35.1 PA0MBO-# 184 15.2 GI4DOH-# 158 22.7 PA3A-# 102 20.8 DD0CW-# 51 20.5 YO4SVZ-# 30 13.1 DL5KW-# 10 24.9 OH6RE-# 5 27.8 S51D-# 2 24.0 GM0ELP-# 2 10.5
Top Twenty Most Spotted Callsigns
World-Wide
Call Spots
--------- -------
K3LR 22429
NQ4I 21485
NR4M 21212
WE3C 20473
TI5W 20469
PJ4X 20330
PJ2T 20096
W3LPL 20087
KC1XX 17987
KM1W 17050
9A1A 16733
W2FU 16594
K1RX 16541
N3RS 14285
W4RM 13955
M6T 13662
M5E 12490
HG1S 11865
W2PV 11744
N4GI 11157
160m
Call Spots
--------- -------
M5O 2324
W3LPL 1704
K3LR 1627
WE3C 1557
OL9A 1543
9A1A 1526
PJ2T 1523
TI5W 1490
HG1S 1360
KM1W 1281
S53O 1246
UU7J 1237
M5E 996
W2FU 942
OM7RU 842
OK2W 817
M6T 777
CS2C 698
W1XX 652
NR4M 639
80m
Call Spots
--------- -------
NR4M 4165
K3LR 4052
PJ4X 3684
9A1A 3582
M6T 3567
TI5W 3497
KM1W 3347
WE3C 3219
PJ2T 3204
W3LPL 3111
W2FU 3033
DJ0MDR 3022
KC1XX 2877
M5E 2805
K1RX 2801
NQ4I 2683
HG1S 2566
DJ5EU 2524
VY2ZM 2505
CR2A 2447
40m
Call Spots
--------- -------
NQ4I 6686
K3LR 6133
WE3C 6098
NR4M 5980
W3LPL 5859
N3RS 5793
KC1XX 5791
NN1N 5696
S56X 5537
TI5W 5480
W3UA 5339
YU1LA 5318
S57Z 5175
KM1W 5173
K1RX 5083
PJ4X 4981
PJ2T 4810
W2PV 4589
E74IW 4561
W2FU 4560
20m
Call Spots
--------- -------
NQ4I 7001
NR4M 6496
K3LR 6060
PJ4X 5713
WE3C 5696
W3LPL 5389
PJ2T 5182
EF8S 5163
K1RX 5140
KC1XX 4993
TI5W 4985
9A1A 4802
W2FU 4788
SO4M 4586
HA7GN 4472
M6T 4354
W4RM 4315
N2MF 4120
GM3POI 4043
KM1W 3902
15m
Call Spots
--------- -------
FY5KE 4235
HD2A 4002
NQ4I 3508
K3LR 3471
WE3C 3415
TI5W 3371
PJ4X 3327
ZD8Z 3325
PJ2T 3293
NR4M 3077
KC1XX 3015
W2FU 2952
W3LPL 2857
KM1W 2765
W4RM 2757
9A1A 2694
N4GI 2658
N7DD 2633
K1RX 2627
WA3A 2483
10m
Call Spots
--------- -------
PY2YU 2140
PJ2T 2084
PJ4X 2027
LU5FC 2022
HK1R 2018
CE1/K7CA 1812
TI5W 1646
LU6UO 1460
KH6LC 1312
CW5W 1301
KH7M 1283
LS1D 1234
NQ4I 1197
W3LPL 1167
PS2T 1120
K3LR 1086
LU3DAT 1039
J39BS 966
TI5N 860
NR4M 855
North America
Call Spots
--------- -------
K3LR 22429
NQ4I 21485
NR4M 21212
WE3C 20473
TI5W 20469
W3LPL 20087
KC1XX 17987
KM1W 17050
W2FU 16594
K1RX 16541
N3RS 14285
W4RM 13955
W2PV 11744
N4GI 11157
N6BV 10931
K5GO 10477
KB1H 9942
K9CT 8698
K0DQ 7003
N2NT 6835
South America
Call Spots
--------- -------
PJ4X 20330
PJ2T 20096
P49Y 5477
P49V 5371
LS1D 5096
PS2T 4928
FY5KE 4245
HD2A 4002
CW5W 3810
HK3TU 3560
PV8DX 3525
PZ5RO 3159
LU1DZ 2414
PY2YU 2140
LU3DAT 2056
LU5FC 2022
HK1R 2019
HC2/W7SE 1825
CE1/K7CA 1812
PY2NY 1699
Europe
Call Spots
--------- -------
9A1A 16733
M6T 13662
M5E 12490
HG1S 11865
RL3A 10570
OM7M 9279
HG7T 8976
4U1ITU 8810
TM6M 8413
HG6W 8157
S53MM 7937
S50A 7738
SN2B 7724
LX7I 7625
OE3K 7306
IR4M 7205
OM3BH 7141
CS2C 7011
9A8M 6796
F5CWU 6726
Africa
Call Spots
--------- -------
CR3L 8198
EF8S 5243
EF8USA 4664
EF8R 4626
CQ3B 3873
ZD8Z 3404
6V7S 3048
3V8SS 2684
EA8CN 2629
CR3A 1988
EA8OM 1757
5C5W 1470
EA9EU 810
EA8ZS 631
T5G 593
ST2AR 380
EA8BQM 372
V51YJ 318
ZS2I 288
ZS1EL 260
Asia
Call Spots
--------- -------
JA3YBK 6184
JE1ZWT 4409
JA1YPA 4298
7J1YAJ 3532
RU0FM 3019
JH4UYB 2675
JR1AIB 2400
RW0CWA 2321
JA1JKG 2275
JE1CKA 2211
JA6GCE 2175
JS3CTQ 2129
JH3PRR 1796
JF1SQC 1778
JA6SHL 1618
JE1LFX 1476
JN4MMO 1415
JH0INP 1401
BA5CW 1389
JF1NHD 1360
Oceania
Call Spots
--------- -------
KH6LC 9749
KH7X 4533
ZL3IO 1562
KH7M 1283
VK2IM 1055
KH6/AA4V 940
KH6CW 854
WH6R 829
VK2DX 824
NH2T 530
ZL3TE 516
ZM4M 488
KH6MB 470
KH6FP 315
VK7GN 297
DU1/JJ5GMJ 248
VK6LW 242
YB1ALL 237
KH6/VE7AHA 225
VK4IU 196
Monday, February 13, 2012
Making Best Use of The RBN in the ARRL DX Contest
If you're not planning to operate Assisted or Multi-op in this weekend's contest, you can skip this now. Otherwise, let me offer a few thoughts that may help you make best use of Skimmer spots from the Reverse Beacon Network. 1. Use a node that allows you to include or exclude Skimmer spots with a simple command. Both ARClusterV6 and VE7CC Cluster nodes have this capability. Some logging programs and Telnet clients may also have this capability built in 2. If you use the RBN and your logging software lets you set a packet time-out value, set it for no longer than 10 minutes. The skimmer software automatically re-spots stations that continue CQing on the same frequency only once every 10 minutes, but typically such re-spots appear within a few seconds of the 10-minute threshold, since we now have pretty wide coverage. You'll cut down on the number of "stale" spots this way. 3. By all means *do* use filtering of some sort to limit the number of Skimmer spots you receive. The major contest software packages can all handle the load, but except in very special circumstances you'll want to filter. For example, if you filter by geographic origin of spots, you can pretty much assure yourself that you'll be able to hear everything that is spotted. ARCluster version 6 also has the ability to set a threshold and not pass you a spot until at least "x" Skimmers worldwide have concurred. This can materially help you to reduce busted spots. 4. Be skeptical of spots that appear on your bandmap on the very same frequency as someone who has already been spotted there. Despite all the care VE3NEA has taken to prevent it, stations that call more than once, very close to the running station's frequency and CW speed, may be mistaken for runners and spotted by a Skimmer. As you can imagine, this may be particularly common on the low bands. See you in the pileups!73, Pete N4ZR
Thursday, January 19, 2012
Aggregator 2.0 - A Great Leap Forward
While we were all busy with the holidays, Dick, W3OA was producing the next-generation Aggregator. We think you’ll agree that it is a real improvement. With this Aggregator, you’ll be able to automate changes in which bands you’re covering, and make different choices for contests and regular operating. If you’re troubled by sending busted spots due to local RFI or other causes, you can cull these out with the new Bad Call filter. All the features of the Aggregator are now arranged on tabs, to make the program easier to use.
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