KB9AMG's blog

To test the theory that some duplicated bad decodes are the result of multiple strong stations being received, I looked in the wspr database for VK3 transmitters on 2m over the past month.

I found 29 VK3 callsigns that were hybrid decodes (3 different stations transmitting, resulting in 4 different decodes).

I ran 4 instances of wsjt-x - one as a receiver and
the other 3 as transmitters (through virtual audio cable). The transmitters were at 1480Hz, 1500Hz, and 1520Hz - this created several signals across the entire waterfall every 20Hz.

With help from OZ2M's WSPR Hash Collision Checker, I've created a list of hash collisions that have occurred over the past month.


Also available is a collision-free hashtable.txt file which includes all transmitters active within the past month that have a unique hash value and grid.

An X1.5 solar flare on July 3rd, 2021 at 14:29Z which affected most of NA, EU, SA, and AF reduced spot counts by 80-90% in the minutes following the event. Spots counts had returned to normal about 20 minutes later. This resulted in a 15-20% drop in the hourly totals.

Another interesting 10m spot. I spotted G8CQX-IO81xu (20W) on 10m at an unusual time (local time 3:08 a.m.) This was more than 2 hours before sunrise. About 1.5 hours before dawn, and 50 minutes before nautical twilight. It was, however, about 5 minutes after the start of astronomical twilight (time when full darkness ends).

Wales, Wisconsin
Astromomical twilight begins (full darkness ends) 03:04 a.m.
Nautical twilight begins (First light) 03:59 a.m.
Civil twilight begins (Dawn) 04:44 a.m.
Sunrise 05:19 a.m.

Heard IW4EGP using 5 Watts on 10m during a sporadic E opening at a distance of 7562km. Here are the spots of all the stations hearing IW4EGP JN64gb at 1452Z on 2019-06-21.

SNR Dr Frequency Reporter Grid .. km . az
--- ------------ ---------------- ---- ---
-21 1 28.126087 KB9AMG.....EN52tx 7562 309
-04 0 28.126087 G6KSN......IO82xj 1419 316
-09 0 28.126155 M6RZA......IO92bj 1409 316
-08 0 28.126087 G3YHV......IO81pl 1402 311
-27 0 28.126105 G8CQX/A....IO80jq 1392 307
-20 0 28.126085 M0AQY......IO81re 1376 310

I added a new 7-day km/Watt transmitter rankings list to the top of the km/Watt pages.


On 17m, DL6NL has the highest total (almost 3 times as much as the next highest station).

The rankings are based on the last 7 days of wspr reports and add all the km/Watt values of the unique reporters hearing the transmitting station each day.


Thanks to Gordon K0GUN for the suggestion.

I added power levels to the transmit and receive station summaries. Each combination of callsign, 4 or 6-character grid, and power level (if transmitting) is counted as a separate station.

Transmit summaries for each different power level used by a station. Multiple bands grouped together then sorted by distance. Shows number of different reporters and total spots.

Using the latest full day of wspr spots, I created a list that shows which grid squares appear in the most spots. Yesterday, the 10 most active grid squares were:

JN49 45307
JO21 36559
IO91 36484
JO22 33888
JO31 29718
JO42 28409
JN58 26031
IO93 24243
JO32 22065
IO83 21285

The complete list is at http://mardie4.100webspace.net/wspr_grids/index.html

Added some new WSPR stats to my website. It is similar to the RBN section and has some advantages over the top wspr spots/spotters stats which are only updated monthly. The new WSPR stats section provides daily stats for all stations (tx/rx, SWL, or tx-only), uses full callsigns (multiple /'s, dashes, and underscores), handles 4 or 6-digit grid squares, and adds the power level (dBm) to transmit stations.

Look for "WSPR Spots stats" near the bottom of the webpage at http://mardie4.100webspace.net/

Just by chance I was checking 10m around midnight and heard Dave, W1VR (EL98it) 5 times between 0552z and 0628z. First three decodes were strong at -6,-7, and -6. Finished with -24 and -24.

I was heard once at 0600z.
2015-11-12 06:00 KB9AMG 28.126126 -29 0 EN52tx 5 W1VR EL98it 1698 156

dxmaps.com was showing a sporadic E cloud in northern Georgia.

Other nearby stations WJ9H (EN53ga) and K9AN (EN50wc) had already been reporting W1VR for about an hour by the time I tuned in.

Sporadic E is an interesting propagation mode.

Had some interesting WSPR reports on 15m with Hisa, 7L4IOU, on 15m this morning.

After checking VOACAP and doing some research, I think these were long path reports. This would be a record WSPR distance for me at 30073km. Next highest is VK6XT on 20m at 22509km.

2015-06-19 14:44 7L4IOU 21.096056 -9 0 PM95wr 2 KB9AMG EN52tx 9991 33

2015-06-19 14:48 KB9AMG 21.096043 -26 0 EN52tx 5 7L4IOU PM95wr 9991 323

2015-06-19 15:04 7L4IOU 21.096057 -23 0 PM95wr 2 KB9AMG EN52tx 9991 33

The last 2 months have been very active for WSPR. Excellent server uptime and improved signal decoding (K9AN decoder) have really helped the spot numbers grow.

January 2015 was the first time there was over 8 million spots for the month. January had 8,037,932 spots. Prior to that, the closest we came to 8 million was in March of 2014 which had 7,917,817 spots.

Had an unexpected spot from VK6XT on 20m late this afternoon:

2014-12-27 23:26 KB9AMG 14.097140 -22 0 EN52tx 5 VK6XT OF86td 17546 286

other stations heard by VK6XT at the same time:

2014-12-27 23:26 K4COD 14.097164 0 0 EM73sc 2 VK6XT OF86td 17969 262
2014-12-27 23:26 K4RCG 14.097148 -16 0 FM08xl 2 VK6XT OF86td 18520 285
2014-12-27 23:26 KE7TYT 14.097112 -23 0 DN40bv 5 VK6XT OF86td 15631 264
2014-12-27 23:26 HB9CZF 14.097079 -23 0 JN47ch 1 VK6XT OF86td 14081 103
2014-12-27 23:26 VE3PLE 14.097022 -12 1 FN25bg 5 VK6XT OF86td 18302 313

A large X1.6 solar flare occurred while I was listening on 10m. I saved a screenshot of the wspr screen to show the wavy signals that immediately followed the start of the solar flare at 1402z.

Files are here: http://mardie4.100webspace.net/pics/

One file is the screenshot of my wspr screen. Notice the wavy signals at 1404z and 1406z.

The other files are a graph of the X-ray flux from the NOAA website. The flux rose very quickly at the start of the flare.