AN INTRODUCTION TO WSJT

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AN INTRODUCTIONTO WSJT

• Lets go fishing, you never know what you will
  catch.

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YOU NEVER KNOW WHAT YOU WILL CATCH.

• Amateur Radio in its purest form is about radio
  and radio propagation.
• Many of us entered into this hobby because of our
  fascination with radio and radio propagation.
• The unpredictable nature of radio propagation
  keeps our interest. You never stop learning.
• This unpredictable nature is like fishing. You
  never know what you will catch.
• If every time you threw in your line, you caught
  a big fish, it wouldnt be much fun would it?

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WSJT SOFTWARE by K1JT

• WSJT is the name of a computer program. The name
  stands for Weak Signal communications by K1JT.
• WSJT has four modes of operation intended for
  VHF, UHF or microwave communication.
• K1JT provides this program for free!
• Source code is also available for free!
• It is available on the web at K1JTs WSJT page
  http//pulsar.princeton.
  edu/joe/K1JT/

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JOE TAYLOR K1JT

• Joe Taylor, K1JT, the author of WSJT, obviously
  shares a fascination with radio as do most hams.
• K1JT is a Nobel prize winning radio astronomer,
  well qualified to write software like WSJT.
• K1JTs knowledge of detecting extremely weak
  radio signals is apparent in the function and
  performance of WSJT.
• Joe wrote WSJT and he operates WSJT often. He is
  an active VHF operator on WSJT and the other VHF
  and above weak signal modes.

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WSJTs FOUR MODES

• FSK441 VHF communication via meteor scatter
  using reflections from very small meteors. A
  meteor shower is not needed, it works 24/7.
• JT6M The same purpose as FSK441 but optimized
  for
• 6 meters. It is slower in speed but 10 dB more
  sensitive.
• JT65 Communication with very weak signals of
  roughly constant strength. Troposcatter and
  Earth-Moon-Earth (EME) communications, VHF, UHF
  and SHF.
• EME Echo Tests station performance by detecting
  and measuring EME echoes. Noise measurements and
  path calculations.

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FSK441

• Designed for VHF high speed communication using
  very brief pings of signals reflected from very
  small meteors, between the size of dust and a
  grain of sand.
• These meteors ionize the E layer at about 100 km,
  and support communication from 400 to 1500 mi.
• These small meteors are present 365 days a year
  and QSOs may be made 24/7. A shower is not
  required.
• A good 100 ms reflection will decode a full set
  of calls! A 20ms ping will decode 3 characters.

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JT6M

• Also for high speed meteor scatter, but
  especially optimized for the 6-meter band.
• Meteor reflections on 6 meters are stronger and
  longer.
• JT6M is slower, taking advantage of the longer
  reflections while providing 10 dB better
  sensitivity than FSK441. Shannon's Theorem.
• It is not appropriate for use above 6 meters,
  FSK441 is better on 144, 222 or 432 MHz.

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JT65

• For extremely weak but slowly varying signals
  such as those found on troposcatter and EME
  paths.
• JT65 can provide a 15 dB improvement over a
  skilled EME operator on CW!
• A 15 dB improvement is like having a array of
  least sixteen antennas instead of one, or a kW
  instead of 30 watts!
• It makes EME possible with a small station and
  for operators that are not proficient at CW.
• WSJT does NOT do everything for you! EME is
  still a challenge.

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EME ECHO

• EME echo testing without this software is
  difficult using only your ears.
• WSJT provides a qualitative way to measure your
  station performance.
• In the EME echo mode WSJT will measure noise from
  the Sun and other sources.
• It is easier than other ways of performing noise
  measurements.
• This testing ability allows a weak signal
  operator to establish a baseline for station
  performance and evaluate changes.

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OK, LETS GO FISHING

• You probably already have the radio and the
  computer. The expensive part.
• You need more than just the tackle box.
• You cant go fishing without a pole! You will
  need an antenna.

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WSJT FSK441 MODE

• pings heard at K1UHF

• Transmit CQ

• Transmit Multi Tone 73s

• Transmit Single Tone 73s

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A SMALL POND METEOR SCATTER

• 2 meter meteor scatter contacts from K1UHF,
  FN31fh.

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A FISHING POLE TO CATCH METEORS?

• You dont need much aluminum.
• With a loop antenna or 3 element beam and only 25
  watts you can work bigger stations.
• 1000 mile FSK441 signals have been heard with a
  vertical! From Connecticut, K1UHF has worked
  five stations West of the Mississippi that had
  less than 25 watts and 3 element beams or
  smaller.
• Bigger may not be better. Meteors sweep across
  the sky. An antenna with a tight horizontal
  pattern may not always help.

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WHAT OTHER FISHING GEAR?

• A 6 or 2 meter multi-mode (USB) radio.
• A computer with Windows 98 or higher and a
  Pentium 75 or better.
• A sound card interface, such as a RIGblaster.
  Microphones in front of speakers will work for
  starters.
• A free copy of WSJT.
• Accurate frequency calibration, - 200 Hz.
• Accurate computer clock. SNTP, Dimension 4.

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FISHING TECHNIQUE

• You can make contacts 24/7 with FSK441 MS
• There are almost always enough good meteors to
  make a contact during a 1/2 hr sked.
• Late evening to midday is better.
• WSJT doesnt work well during a shower, pick up
  you microphone and switch to SSB.
• It is unlikely you are going to tune around and
  find someone calling CQ on MS.

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FISHING TECHNIQUE

• Most contacts are made with skeds.
• Random contacts can be made with WJST during a
  contest or minor shower.
• CQs are done on the random calling frequencies of
  50.270 or 144.140 MHz.
• Use W0UKs Ping Jockeys web page to make a sked
  or to monitor activity http//www.pingjockey.net
  /cgi-bin/pingtalk

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PING JOCKEYS
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FISHING TECHNIQUE

• Set WSJT up with you call, 6 digit grid square
  and for PTT activation.
• Tune in a clear frequency and click monitor
  wait a few seconds then hit stop to measure and
  set the WSJT receive audio level.
• Go to the Ping Jockeys web page find skeds in
  progress to monitor (receive).
• Set your USB receiver dial reading to the sked
  frequency and watch the DF.
• You will hear the pings. Wait a bit and WSJT will
  decode the signal.

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YOUR FIRST CATCH

• To monitor other QSOs be sure to listen to a
  station 500 to 1000 miles away.
• Type his call in to the To radio box and click
  Lookup, WSJT will show your beam heading and
  the distance.
• You found the fish now catch one, make a sked.
• But first Read Ping Jockeys You must read
  this, also read the WSJT manual and help files.
• To make your first sked find a big station, type
  that you want your first sked on Ping Jockeys.

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YOUR FIRST CATCH

• Coordinate the time, frequency, who transmits
  first and if A B or C tones will be used. For
  example, post W8WN 144.128, 0230 Z, your 1st
  A. The Westerly station is usually first in
  North America.
• Type in the other stations call, aim your
  antenna. Select TX First or not and ST Msg or
  not.
• Hit a tune button and check for transmit audio
  reaching the radio at the proper drive level.
• Turn Auto ON to start WSJTs transmit/receive
  sequencing.

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YOUR FIRST CATCH

• Sit back and listen for a meteor ping.
• If you hear a good meteor WSJT should decode on
  the next over.
• If you get good copy during a sequence MAKE SURE
  that you change your transmit message to the next
  APPROPRIATE message.
• BTW you may change the message during transmit.

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ENJOY YOUR MEAL

• Exchange call signs, signal reports, rogers and
  73s and you have made your first valid QSO.
• Log it! Youre a Ping Jockey!
• Congratulations you never know what you will
  catch.
• You are probably hooked.
• You could spend the next few years working all
  the stations within MS range but how about some
  more distant contacts?

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CATCH THE BIG ONE

• JT65 EME will take a bigger fishing pole and
  better tackle (more power) than FSK441 MS.
• EME is the ultimate DX, dont think it is easy.
• EME requires that you station performs perfectly.
• JT65 EME contacts dont need anything near as
  much as a CW station but you do need a good
  setup.
• JT65 EME will be a rewarding accomplishment.
• It is possible to work another 2 meter station if
  you both have only a single long yagi and 100
  watts.

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WSJT JT65

• AH6LE on JT44
• Calling AH6LE
• Sending rogers

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CATCH THE BIG ONE

• Put a good GaAs FET preamp ahead of your
  receiver.
• Use low loss feed line, preferably after the
  preamp.
• You may wish to use a simple antenna setup near
  the ground. Manual azimuth and elevation
  rotation by bore sighting the Moon is cheap and
  effective.
• If you already have a large beam up high with
  only an azimuth rotor you will be limited to
  operating near Moonrise or Moonset.
• When you think you have everything set up
  properly use the WSJT Echo Mode and check your
  echoes.

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CATCH THE BIG ONE

• You may not find your own echoes with WSJT but
  you should be able work the larger stations.
• Go to the Ping Jockeys JT65 page and monitor some
  skeds, pick the big stations first.
• Keep your antenna pointed at the Moon, it moves.
• Make sure you time and frequency are calibrated
  as well as you can.
• If you are decoding signals with success you
  should be ready to try a sked.

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CATCH THE BIG ONE

• Make a sked on the Ping Jockeys JT65 EME page.
• Again get all the details correct between both
  stations.
• If you both transmit and receive during the same
  sequence it does not work well. BTDT
• The station that has Moonrise first transmits
  first, opposite MS.
• You may have a one way path, the craters on the
  Moon do funny things. Actually Faraday rotation.
• A full Moon is always better, there is more
  reflecting surface, right?

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CATCH THE BIG ONE

• Got you didnt I! It is actually worse, more Sun
  noise.
• It is better to operate on an EME weekend when
  the Moon is at perigee and degradation is low.
• JT65 has message averaging. It lets you decide
  whether to Include Exclude or Fold
  messages.
• The JT65 message averaging can make a big
  difference if used properly.
• Once you have made you first contact, you will
  think it was worth it 500,000 mile DX.
• With a small station, QSOs are difficult, but
  once you get the bug you will put up that big
  array.

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WSJT RELATED WEB LINKS

• K1JTs WSJT page
  http//pulsar.princeton.edu/joe/K1JT/
• WOUKs Ping Jockeys real time chat page
  http//www.pingjockey.net/cgi-bin/pingtalk
• WA5UFHs meteor scatter etiquette page
  http//www.qsl.net/wa5ufh/DOS/Etiquette.htm
• W8WNs meteor scatter page http//www.qsl.net/w
  8wn/hscw/papers/hscw-sop.html
• WB5APDs JT44 EME tips page
  http//www.qsl.net/wb5apd/jt44-eme-tips.html
• WEST MOUNTAIN RADIO, RIGblaster sound card
  interfaces home page http//www.westmountainradio
  .com