The Old Codger's Guide to JT65A and
JT9 via WSJT-X Software
By Andy K3UK (This article may be freely reproduced with credit
to the author)
Version 1.01 , a work in progress.
After a few hours of use, I feel the new WSJT-X is very
useful. When I wrote the
Complete Bozo's Guide to JT65A years ago, I teased the WSJT
author, Joe Taylor K1JT, for being so smart. There is an
element of that same sentiment when considering the WSJT-X software
with the new "dual mode" capability. Aside from the intellect
that goes in to the appearance of the software , the GUI is simple
and effective, there is also the brain power that came up with the
amazing "split" transmission method that is the centerpiece of
WSJT-X V1.1 . Despite Joe being a pretty smart bloke, I
see he has a "team" of hams helping with the development of
this project . This group of smart people have made weak signal
DXing via the JT65A and JT9 mode much easier for us in the bozo
classes. Our thanks should go to Joe K1JT plus AC6SL, AE4JY,
G4KLA, PY2SDR and VK4BDJ.
What Is It ?
For those still in the dark ages, JT65A and JT9 are digital modes
that have become quite popular within the past few years. They
are not "rag chew " modes where you have a 10-15 minute "chat" about
your recent surgery , or the blue LED's that you installed in your
$5000 Icom. These are digital modes where you exchange your
callsign, grid square, and signal report , and a brief "73", via a
series of 46 second transmissions that your computer decodes.
The nature of these digital signals is such that even VERY weak
signals are detected and decoded by your computer's sound card, thus
most operators use these modes at power levels below 5 watts.
Many use power levels below 1 watt. Above 10 watts is frowned upon!
It is always interesting to see how our attitudes and abilities
change as we age. When I wrote the Complete Bozo's Guide to JT65A, I
made fun of the length of time JT65A takes for a QSO to be
completed. Those were the days of rapid-fire RTTY contesting,
where we worked 5 QSOs per minute , and did so without much effort.
Nowadays, I like the fact that there is a 46 second transmission
followed by a 14 second period that allows my brain and my computer
to reflect on the meaning of life (it is 42) and to have a good
think about the callsign and signal report that is about to
pop up on my machine. I can take a minute or so between transmission
cycles, log the QSO, look the other station up on HamQTH or QRZ,
double check I actually have an antenna plugged in, and engage
in a few second of meditative mindfulness exercises
designed to help me cope with the fact that my old brain screwed up
again and since I sent "73" rather than the expected signal
level information. In about another 10 years, we should be at
the developmental level where our brain's are aided by a cognitive
assistant in WSJT-XX V100.1 . When we press a "macro" out of
sequence, WSJT WSJT-XX V100.1 will say " Excuse me Sir, are
you really sure you want to do this? You are going to look
really stupid sending 73 before you even send your signal
report". That same 2023 version of WSJT=XX will also come with
a sub-mode feature that instead of detecting weak signals, it will
detect moisture levels in your shack. As your drool content
exceeds the drool "squelch" level automatically set by WSJT=XX
V100.1 (this is based an your age and the outcome of a cognitive
functioning test that you complete in the configuration area) , a
bib comes out and wipes your chin periodically.
I digress (something that old codger's practice a lot).
Anyway, the intention behind WSJT-X V 1.1 (may be up to 1.2 by the
time you read this) is to allow us to monitor two different
digital modes at once. As a younger ham, I would have thought "who
needs special software to do that? " You can always open a
JT65A application and then a software package that decodes JT9, have
two applications running at the same time. Well, you could..
but WSJT-X now makes dual mode monitoring much easier. In fact, it
automates the whole process. Your old brain does not even need to
know what mode you are decoding or what mode you need to be
transmitting with. Joe and his team of smart dudes take care
of all that for us.
What Skills Do I Need ?
1. The ability to set your computer's clock accurately and keep it
2. The ability to connect your radio to a sound card for receive and
transmit (receive only, if an SWL).
3. Be able to use a computer mouse or keyboard (fingers, feet , or
nose will work just fine). I have not tried it with a touch screen.
Installing the software:
Assuming you remember which folder you downloaded the software to,
go to that folder and click on the WSJT-X file. The install
will go to a folder that you specify, . Once you have done this,
boot up the program. Take a deep breath, prepare to be amazed.
Setting Up The Software:
Boot up the software, then click on SETUP , you will find this in
the upper left-hand corner. Then click on CONFIGURATION.
Place your callsign in the appropriate box and also you Maidenhead
grid square. You then have to do perhaps the most tricky part,
set up the software to be controlled by your transceiver. That
is important for most digital mode software applications, but even
more important for WSJT-X. That is because the software
performs some voodoo magic , and the rig control is the essential
ingredient for the magic potion.
If you already have digital mode software like Fldigi, Winwarbler,
DM780, Mixw, Digipan, RMS Express, Airlink Express, or Multipsk,
WSJT-X will most likely work if you use the same settings for rig
control and PTT. Rig control allows WSJT-X to know what
frequency you are on , and PTT ("push-to-talk") enables your
transceiver to switch between receive and transmit status . In the
area marked RIG, select your model/brand of radio from the
list and set baud rate, comm port, and other parameters that vary
from brand to brand of radio. IF you prefer (I do) , you can have an
application like Commander
(DX Lab Suite) or Ham Radio Deluxe control your radio. WSJT-X
interfaces well with Commander, my preferred rig control
You should also pay attention to the "POLLING" interval. I thought
this was a reference to whether I wanted the Gallup Company to call
me asking if I still thought Rand Paul was crazy. I set it to
zero, I received no calls from Gallup, but rig control was not
fully operable. Then some younger, smarter, hams told me
that Polling was a reference to how often the software says "What's
Up?" to the radio . The software needs to know "what's up" every now
and again, to know which frequency, mode, your radio is using.
"Polling" sounds technical, thus better than a little set-up
box that says "Yo radio, what's up?"?.
Make sure you tick the box ("check" to those that speak American)
that says "ENABLE CAT". This is not a reference to your cat ,
Tiddles. This is the term used to imply your radio is
controlled by the computer.
After you have put in the various specification for your radio and
computer , you also need to tell WSJT-X which sound device you are
using for audio IN (from radio to computer) and audio OUT (from
computer to radio, to antenna, to other end of the world).
That is about all you need to do to set things up. There are a
few other bells and whistles , mostly placed there to remind us old
codgers that we are increasingly technologically challenged.
I'll explain the bells and whistles later in this article.
Play around with the PTT and CAT test buttons, If they fail, double
check you settings, make sure your radio is ON. If they still
do not work, join the WSJT mail list and
ask for help. Many radios perform PTT functions via
CAT. This is just to confuse me. Some radios do not
support PTT via CAT. Some operators also prefer to have a
separate PTT function. If you are going to use CAT AND a
separate PTT, you will need to specify TWO serial ports in the
WSJT-X software configuration area.
Here is a quick video of me setting up WSJT-X for my radio.(I had
added no explanations because it seems self-explanatory. I may
add more details when I update this article )
In the above video, I briefly display menu of options that a user
can decide to use, or not to use. You see this list when you
click on Setup in WSJT-X . I have opted to enable
"Log dB comments to log".
This places the signal report I receive from the other station
in the log book section of WSJT-X
"Prompt me to log QSO" .
With this option enabled, when I send my 73 message, or my free
text message, the log book pops up and reminds to log the QSO
"Blank line between decoding period".
This inserts a blank line between decoding periods , makes it
easy for you to read.
"Display distance in miles".
Those us old codgers that have STILL not gone metric! WSJT
calculates distance between your grid square and the other
"Double Click on calls sets TX enable"
WSJT-X defaults to a state where you have thje press the Enable
Tx button before a PTT places your rig in transmit. As an old
codger, I always forget this step. Then ,just when a North
Korean station is calling "CQ" , I think I am about to
work him only to find my rig does not go in to transmit and the
North Korean DX is denied the pure privilege of working K3UK! If
you set the "Double Click on calls sets TX enable" option,
the double click on a call that is CQing save you the
enable Tx step.
"TX disabled after sending 73".
You know us old folks are infamous for driving along for miles
with our left blinker ("indicator" to the Brits) on, right
? Well Joe K1JT thought about us when updating his
software. Masny of us have stopped working the station only to
"foget" that TX was still enabled and we accidentally send our
73 message again. Enable this option prevents this.
"Runway TX Watchdog" . Am I the
only one to decide to go to the kitchen in the middle of a
QSO? Then , after getting that soda , I forget I was even
in a QSO and sit down to watch TV in the living
room. Meanwhile every minute my rig is transmitting "P5DX
K3UK r -3" over and over again at one minute intervals!
Turning this option on will prevent this.
I left the remain options unchecked.
There is one other useful option. To activate this you have to
go inside the CONFIGURATION screen. (SETUP then CONFIGURATION)
. See the tick/check box next to "ID after 73"
? This option sends your callsign in CW at the end of
your QSO, the part where you have sent "73". You might think
this is a useful option, but only a "option". However,
USA operators need to be aware that that at least one Bolshevik
"official observer" has sent written notice to JT65A operators who
do not ID with their callsign at the end of a transmission.
This can happen if your last transmission says "TU In-V 3W",
or something like that. Having the "ID after 73" box checked
will save you a pink slip from the bolshie apparatchik.
OK, enough of the meaningless chatter, how do we operate this
Previously, JT65A and JT9 operators were like folks living in
apartheid South Africa. JT65A operators loaded their software
and were confined to the common JT65A frequencies. Cruelly,
but (perhaps deliberately), the JT9 operators transmitted just 2 kHz
away, languishing in the Townships close to the city. JT65A
operators could hear and even see these JT9 folks, but they
had no way of understanding what was being said. The JT65A
operator could switch to JT9 software and finally operate ... but
when they did this... they were taunted by the sounds of JT65A just
a few Hz away. Joe Taylor and his team have become the Nelson
Mandela of the JT-modes. Via WSJT-X you can now speak and decode
JT65A and JT9 at the same time. Separate software is not
needed. In fact there is not much of a brain that is
needed. You don't even need to know which mode you are hearing
or seeing, the software does the thinking for you.
To receive BOTH modes at same time, you do need to set the software.
Click on MODE at the top of the WSJT screen and select JT65 and JT9.
To illustrate this to an old codger, pictures are better than words
(it is like being a child again , when picture books were easier
than reading Chaucer)
In this screenshot there are both the "waterfall" that displays the
signals, and the decoded content of the signals that pop-up
after WSJT-X has had a good "think" about what it just heard.
The decoded signals pop up on you screen around 50 seconds to 59
seconds of every minute. You will see this in the video links also .
In the orange ellipse on the waterfall screen, you will see the
tell-tale signs of a JT65A signal. In this screenshot the
22:01 cycle has about six different transmissions being received ,
some squished on top of each other. In the Yellow ellipse , you will
see much narrower vertical lines. Each vertical line
represents a single JT9 signal. I added a blue ellipse that
highlights the dividing line WSJT-X has been set for. Signals
below 2500 Hz are JT65A and signals above 2500 Hz are
JT9. You can vary that setting if you want. It is
set in the box next to SLOPE at the bottom of the waterfall.
In the screenshot above , do you see the little green circle to the
left of the frequency readout ? Green indicates that WSJT-X is
communicating fully with the radio . If you have an orange
button* instead, that means you do not have full communication with
your rig. If you click on the orange circle, the software will
communicate with the radio and update. Set you "polling" to a
number greater than zero to maintain regular communication with you
So, here you can see how simple Joe's software has made things for
us old timers. Two modes , 12 simultaneous QSOs and we only have to
click on the desired station. The software is smarter than us
and knows which mode you want established. Calling A Station:
So, lets say I wanted to work one of the stations calling CQ at
2201. Let me pick, G0BHK from the above screenshot .
G0BHK is in England and thus a much better person to talk to than
anyone else in the world. All I would need to do is double click* on
the green line (green means he is calling CQ) . The software would
be then ready to transmit. Since his decoded line of text has
a # sign, I know the software will choose JT65 as the mode. Since
that decoded line says 2170 under the FREQUENCY column, the software
will adjust my postilion on the waterfall to 2170 Hz and my
rig will transmit on the desired frequency .
I said it was easy but before I actually call a station, I need to
do perhaps the most important thing in setting up, something that
takes advantage of the voodoo magic in the software. In my rig
(and yours) , I need to set up for SPLIT operation. In VFO-A I
set the common JT65A frequency and in VFO-B I set for the common JT9
frequency. The common JT65A frequencies are stored in a drop-down
list within the software. Usually JT9 signals start 2 kHz above the
usual JT65A frequency. In my example, on 20M, VFO-A is
set for 14076.000 and VFO-B 14078.000 , both USB. My rig
is in SPLIT mode and will transmit using VFO B. The voodoo
magic is that WSJT-X changes the rig's frequency so that your
JT65A or JT9 signal is transmitted on the correct part of your 4 Khz
Take a look at this video (you may need to open "full screen" to get
In this video, I prove I am an old codger by getting the audio
capture settings wrong! So, the video has no sound.
Never mind, the only thing you would have heard is a bunch of JT65A
and JT9 signals wailing away. If you listen carefully, you can
hear my TV's audio with Andy Murray at Wimbledon! There is
another video referenced later in this article, it has sound .
The first video shows a brief few seconds of me monitoring a 4 kHz
chunk of spectrum and then a bunch of decoded signals arrive.
I choose a CQ call. I call the station, station responds
. I reply again with a signal report. The station does
not get my report. So I send again, increasing my power to 10
watts (just to get a good demo video). After the station sends
RRR , indicating that he received all my info.. I send a
personalized 13 character message saying thank-you and referencing
my power and antenna type.. Notice that all I did was place my
rig for the correct VFO A and VFO B base settings and click on the
signal I wanted to work. The WSJT-X did all the figuring out
of where to actually transmit my audio. For this QSO, I was at
3410 Hz in the waterfall , so WSJT used 14078 and a center audio
frequency. If I had selected a JT65A signal with a lower
position in the waterfall, WSJT-X would have changed my transmit
frequency . Note that I set my rig's USB filter width to 4.4
Khz. That is so I can decode audio over the usual JT65A-JT69
range, usually 4 kHz. Most modern rigs have the ability to have a
receive filter in the 4 to 5 Khz range. You do not need to
change you transmit filters, the software's magic removes the need
The next video shows me receiving a signal that happens to be
JT65A. I try to reply and when I transmit you will see the
voodoo magic at work. My VFO B switches to 14076 to work the
lower frequency used by the ZP5 station. Some bloke with the
call sign K1SEA beats me to the ZP5 so I try someone else.
In the videos , you will see me using the ANSWERING CQ messages from
TAB 2 of the message options . They are fairly self
explanatory. The usual sequence is, you respond to
a CQ with your call and grid square. The other station replies
with your callsign her callsign and your signal report in
dB. You reply with a "roger" and their dB report (R+dB button)
. The other station , if they got your report, will send "RRR"
(Roger, Roger, Roger) and you send either the "73" button or a "Free
message" that you create in the Free Msg box. That free
messages can not be longer than 13 characters, spaces included!
Help With Signal Reports:
It is extremely helpful if you join the many hams that report the
callsigns and SNR to the rest of the world. WSJT-X does this
via use of PSK
Reporter. by Philip Gladstone. If you go to SETUP then
CONFIGURATION in WSJT-X, then check the box "Enable PSK Reporter" ,
any signals your station received are send to PSK Reporter.
The maps and log feature at PSK reporter are very useful
More to come.
Questions or to point out stupid mistakes: Email K3UK at
If you want official information try the links below
*The "double click" feature places the station you are calling in to
your transmit buffer. Double clicking can also automatically
"enable transmit" or you can set things up where you HAVE TO click
on the ENABLE TX button . Click on the SETUP menu (upper left of
software) and see the "Double click on calls " option. That
same menu gives you other useful options. In the first video
you will see the options I have chosen to activate.