What is WSPR?

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What is WSPR? Steve Nichols G0KYA
www.qsl.net/g0kya
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What is WSPR?

• The Weak Signal Propagation Reporter
• An automated system designed for sending and
  receiving low-power transmissions to test
  propagation paths on the MF and HF bands.
• The program can decode signals with S/N as low
  as -28 dB

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What is WSPR?

• WSPR was designed and written by Professor Joe
  Taylor K1JT.
• A Nobel prize winner and inventor of WSJT, JT65
  and others.

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How does it work?

• Your system transmits a (just under) two-minute
  long FSK signal with a 6Hz shift.
• The signal contains your callsign, locator and
  power level in dBm.
• And then it listens ....

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How does it work?

• Your system listens for WSPR signals, in a 200Hz
  passband, decodes them and lists them in the
  software.

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How does it work?

• The computers then send their results to
  www.wsprnet.org where they are stored and
  displayed.

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How does it work?
You also have a visual display ...
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How does it work?
... that you can customise by band/time/call
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What do you need?

• A PC running Windows with an accurate clock
  and an internet connection (not essential)
• The WSPR program
• A data interface (such as used for RTTY)
• An HF (USB) rig and antenna See
  http//www.g4ilo.com/wspr.html Can be compiled
  for Windows, Linux, FreeBSD, Macintosh OS/X, and
  most other Unix-like operating systems

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Things to watch out for

• Set the power output in dBm carefully! (5W
  37dBm)
• You don't need to run more than 10W (40dBm)
  some run 1mW (0dBm)!

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Things to watch out for

• Set the right frequency (USB)

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Things to watch out for
Tick to upload spots
Set correct time
Set correct frequencies
Set to 20
Don't let it go red (/-10dB)
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WSPR QSO mode
Joe Taylor There is a 'WSPR QSO mode' in WSJT.
This mode has not become popular, I think in
large part because the data rate is too slow and
the 50-bit messages too constrained. WSPR QSO
should operate near the normal JT65 QSO
frequencies - 14.076500MHz
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How has it grown?
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How has it grown?
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Do WSPR contacts count for DXCC?
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Do WSPR contacts count for DXCC?
Bill Moore NC1L, ARRL Awards Branch Manager
From what I read it appears that this is just
another digital mode and for DXCC it would count
as RTTY.
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So what can you work/hear?
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So what can you work/hear?
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So what can you work/hear?
Just half an hour on 30m with 5W to a mag loop in
the rafters
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So what can you work/hear?
30m 5W MFJ mag loop in loft
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So what can you work/hear?
30m 5W MFJ mag loop in loft
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Can it hear better than CW?
WSPR is about 11 dB better than ear-and-brain
CW. For most operators, the difference is more
like 15 dB."
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What can you do with WSPR?

• Look for fleeting/rare propagation paths eg
  Sporadic E on 10m
• Test antennas
• Do long-term propagation research
• Have fun!

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What are the downsides?

• Not enough stations on often only 2-5 on 10m
• People don't put in the correct locators/power
  levels
• People come and go making long-term research
  difficult
• Data format not conducive to graphing
• WSPR reports signal to noise ratio, not signal
  strength.

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Mistakes/errors/bad decodes?
YA1YOU Afghanistanin HB14 square?? I don't
think so!
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Mistakes/errors/bad decodes?
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Mistakes/errors/bad decodes?

• WSPR may be prone to bad decodes on slow
  machines c400-500MHz processor.
• Local QRM/noisy environments can cause bad
  decodes that PASS the forward error correction
  tests.

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User error

• Reporting captures as being on one band when
  they are actually on another.
• I was in a rush this morning, and in my haste I
  started WSPR without checking the band. All my
  spots for 30m on 2-3 Oct are invalid. I was
  TX'ing and RX'ing on 40m.

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Antenna tests USA (Stu Philips)
Conclusion The vertical dipole (right) generates
longer distance spots in more time periods than
the inverted L.
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VOACAP v Reality F6IRF
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Is propagation bilateral? F6IRF

• K1JT hears F6IRF, but not the other way (look at
  maximums) see http//f6irf.blogspot.com

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High angle at sunrise? F6IRF

• K1JT louder at F6IRF on vertical mag loop (high
  angle) at sunrise - http//f6irf.blogspot.com

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Antenna comparisons G8JNJ
Tests completed on 80m
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Antenna comparisons G8XLH (1)
Tests completed on 30m
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Antenna comparisons G8XLH (2)
Tests completed on 160m
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Dxpeditions TY1MS, Benin (10-27 Oct '09)
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Maritime mobile OE1IFM, Gernot
http//www.oe1ifm.at/ About 2,500 spots on seven
bands in six days. 1W on 80-40-30-20-17-15-12
Grado - Jesolo - Venezia - Chioggoa - Trieste -
Izola - Grado
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Conclusion

• WSPR is a useful tool probably unsurpassed
  for QRP contacts
• As a QSO chat mode it is no match for
  SSB/CW/PSK31/RTTY
• The spot database is useful, but don't believe
  all you see
• It needs more users
• Will it take over from real radio - no!
• Find out more at www.wsprnet.org and
  http//www.physics.princeton.edu/pulsar/K1JT/