Transcript Weak Signal Propagation Reporter (WSPR)

Weak Signal Propagation Reporter
(WSPR)
• WSPR is a soundcard (digital) mode designed
to check propagation conditions.
• Unlike DX beacons, which tell you only what
stations you can hear, WSPR also tells you
what stations can hear you.
• WSPR uses low-power signals, under 10
Watts. In the WSPR community, “QRP
Operation” refers to power levels <500 mW.
Why Use WSPR ?
• Learn something new.
• It helps amateurs around the world
understand signal propagation.
www.wsprnet.org
• It helps you predict where your signal can be
heard & look for band openings.
• It allows comparison of antennas.
• Success depends on participation.
WSPR Signal Format
WSPR Transmissions - 6 HZ BW
Freq. (Hz)
Fc
Suppressed Carrier Freq.
Fc + 1400 Hz
Fc + 1600 Hz
WSPR transmits a USB, suppressed-carrier (SSB) signal.
Each transmission is 4-tone FSK, with a 1.4648 Hz tone separation.
The transmitted signals are in a frequency range from 1400 to 1600 Hz above
the carrier frequency.
Each signal occupies an approximately 6Hz bandwidth.
WSPR can decode signals 28 dB below noise in a 2500 Hz noise BW.
A transmission consists of your call sign, your 4-character grid square, and your
power level in dBm. Each transmission period is 2 minutes long.
(0 dBm = 1mW; 30 dBm = 1W; 37 dBm = 5W; 40 dBm = 10W)
What You Need
• HF Transceiver – crank down power to 10W or
less.
• Computer with a soundcard connected to the
transceiver. 1.5GHz min CPU speed. Computer
clock must be synchronized to UTC. Soundcard
should have 48KHz sample rate or better.
• WSPR software (free) – download from
www.physics.princeton.edu/pulsar/K1JT/wspr.html
• Important – Download the user’s guide as well !
Soundcard Interfacing
Contrary to popular belief, you don’t need
to use a fancy soundcard interface. It can
be as easy as directly connecting the
soundcard to the radio:
But -
Commercial (or homebrew) soundcard
interfaces can provide better isolation between
the radio and computer and better PTT control to
prevent Windows sounds from causing
unwanted transmissions. Try direct first w/ VOX.
From: http://ve3elb.ham-radio.ch/soundcard%20interface.html
Start here : www.physics.princeton.edu/pulsar/K1JT/wspr.html
Download software & user’s guide.
WSPR Frequencies
• Frequencies:
• USB dial (MHz): 0.5024, 1.8366, 3.5926,
5.2872, 7.0386, 10.1387, 14.0956, 18.1046,
21.0946, 24.9246, 28.1246, 50.293, 144.489
• The frequencies are listed on the
www. wsprnet.org webpage.
Also set automatically by the software.
Where to Start
• Install the software.
• Connect the transceiver audio in/out to the
soundcard. Try receiving first.
• Start WSPR. Tune the receiver to the correct
WSPR frequency. Use CAT control if you have
it.
• Have some coffee and wait a while. You
should see (& hear) something like this:
Transmission / reception intervals are every two minutes, starting on the even
minute. Xmit frequency is set by a click of the mouse.
What if it doesn’t work?
(You hear signals, but nothing decodes.)
• Check the setup of the Windows mixer – make
sure that the Line Input is enabled.
• Be patient – remember it takes 2+ minutes (after
the start of transmissions) to decode anything.
• Make sure that the receiver is tuned to the
correct frequency.
• RTFM – Check the User’s Guide, especially
Appendix C.
Go to www.wsprnet.org & Click on Map to see activity
The Weak Signal Propagation Reporter Network is a group of amateur radio operators
using K1JT's MEPT_JT digital mode to probe radio frequency propagation conditions using
very low power (QRP/QRPp) transmissions. The software is open source, and the data
collected are available to the public through this site.
www.wsprnet.org
KD5SG Activity for 30 Minutes on 20 Meters Dec 27, 2010
Previous map expanded for clarity.
Click on any call sign to see details.
30 Meter Activity, a few days later.
Map can be “zoomed” as needed.
Maps can be customized by Call, Band, and Time Period.
You can leave the call sign blank, and set the band to “All” to see everything,
But the map takes longer to load !
Misc. Soundcard Interfacing Information:
“Understanding Soundcard Interfacing” by WM2U :
http://www.qsl.net/wm2u/interface.html
“Soundcard Basics for MARS Stations”:
http://navymars.org/central/reg4/al/basics.htm
“Buxcom Handbook”: http://www.nonstopsystems.com/radio/pskhandbook.pdf
“The Ins and Outs of a Soundcard” by K1UHF, QST, October 2003:
http://www.westmountainradio.com/pdf/Ins&Outs.pdf
Note: Many soundcard interfaces use an optoisolator to control the PTT
function. The Optoisolator family (4N29 to 4N33) is not recommended
since some PTT circuits may not switch properly due to the high saturation
voltage of the Darling output transistor. The Avago Tech. FET output,
optically-coupled relay (#ASSR-1219-001E) from Mouser Electronics is a
better choice.
Commercially made interfaces are available from West Mountain Radio,
Tigertronics, MFJ, and others.
What’s Next ?
Work the world !
Try WSJT (JT65) for HF QRP confirmed QSO’s.
http://www.physics.princeton.edu/pulsar/K1JT/wsjt.html