steve nichols g0kya, rsgb propagation studies committee what is wspr? steve nichols g0kya

Steve Nichols G0KYA, RSGB Propagation Studies Committee

What is WSPR?What is WSPR?

Steve Nichols G0KYA Steve Nichols G0KYA www.qsl.net/g0kyawww.qsl.net/g0kya


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


What is WSPR?• WSPR was designed and written by Professor Joe Taylor K1JT.

• A Nobel prize winner and inventor of WSJT, JT65 and others.


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 ....


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


How does it work?• The computers then send their results to www.wsprnet.org where they are stored and displayed.


How does it work? You also have a visual display ...


How does it work? ... that you can customise by band/time/call


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


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)!


Things to watch out for• Set the right frequency (USB)


Things to watch out for Tick to upload spots

Set to 20%

Set correct frequencies

Don't let it go red (+/-10dB)

Set correct time


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


How has it grown?


Do WSPR contacts count for DXCC?


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.”


So what can you work/hear?


So what can you work/hear?

Just half an hour on 30m with 5W to a mag loop in the rafters


So what can you work/hear?30m

5W +MFJ mag loop in loft


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."


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!


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.


Mistakes/errors/bad decodes?

YA1YOU – Afghanistanin HB14 square??

I don't think so!


Mistakes/errors/bad decodes?


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.


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.”


Antenna tests – USA (Stu Philips)

Conclusion: The vertical dipole (right) generates longer distance spots in more time periods than the inverted L.


VOACAP v Reality – F6IRF


Is propagation bilateral? – F6IRF

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


High angle at sunrise? – F6IRF

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


Antenna comparisons – G8JNJ

Tests completed on 80m


Antenna comparisons – G8XLH (1)



Antenna comparisons – G8XLH (2)



Dxpeditions: TY1MS, Benin (10-27 Oct '09)


Maritime mobile: OE1IFM, Gernothttp://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


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/

steve nichols g0kya, rsgb propagation studies committee what is wspr? steve nichols g0kya

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