Work the World with WSJT-X,
Part 1: Operating Capabilities
The first of a two-part tutorial about the most popular digital software in use
today, from the people who designed and developed it.
Joe Taylor, K1JT; Steve Franke,
K9AN, and Bill Somerville, G4WJS
One of the greatest pleasures in Amateur Radio is the thrill of establishingtwo-way communication with likeminded hobbyists far away, using
one’s own equipment. We enjoy making such contacts on our own, without
recourse to commercial carriers or
infrastructure. Since the 1930s, amateurs have known that worldwide communication is possible on the HF
bands (at least some of the time) withpower levels no more than 100 W andantennas as simple as half-wave
dipoles. Twenty-first century digitalcommunication techniques based on
information theory make these things
possible at much lower power levels,
even with compromise antennas. Optimized methods of coding and modulation enable these and many othersurprising feats — for example,
DXCC using low power and an indoor
antenna; two-way contacts on the 6and 2-meter bands at any time overdistances of 500 – 1,300 miles (800 –
2,100 kilometers) using reflections
from ionized meteor trails; and EarthMoon-Earth (“moonbounce”) contacts
over worldwide distances, whenever
the Moon is up at both ends of a path.
Starting in 2001, the software program
WSJT has facilitated making two-way
contacts with extremely weak signals.
The latest version of this open-source,
multiple-author software package iscalled WSJT-X. It supports nine distinct protocols or modes, each optimized for a different frequency range
or type of propagation. These modes

Figure 1 — Waterfall spectrogram recorded by WSJT-X at 14.076 MHz on September 19, 2015.
The frequency scale gives audio frequencies in hertz above the transceiver dial frequency. Of
the 23 decodable signals in this 1-minute recording, eight are so weak that they would be inaudible to a human — even if they were the only signal in the passband.

are not designed for long conversations, or “ragchewing.” Rather, they
concentrate on efficient exchange ofsuch basic information as call signs,
Maidenhead grid locators, signal
reports, and acknowledgments at thelowest possible signal-to-noise ratios,in the space of a few minutes or less.
Short user messages are encoded into
audio-frequency waveforms that canbe transmitted and received with stan-mation required for a minimal valid
QSO (contact) is typically exchanged
and acknowledged after two or threesuccessful transmissions from eachstation.

The first publicly available version of
WSJT1 was designed for meteor scatteron the VHF bands. The software has
been in continual development since2001, with improved performance,
added user-convenience features, andnew operating
modes. The curThis mathematically sophisticated method
rent program verof encoding information ensures that withsion supports fourmodes that usevery high probability, messages displayed
1-minute transmit/by the decoding software will be exactly
receive (T/R)
those that were originally encoded.
sequences. Each ofthese “slow”
modes — JT4,
dard SSB transceivers. At the receiving
JT9, JT65, and QRA64 — uses a disend, recovered audio is converted backtinct coding and modulation scheme
to digital samples and the software cardesigned to optimize weak-signal
ries out a reverse transformation tocommunication on a particular type of
decode the message. All transmissions
propagation path, with high reliability
are timed and synchronized with Coorand good bandwidth efficiency. The
dinated Universal Time (UTC). Informost recently introduced slow mode is
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October 2017   1

called FT8, and it’s less “slow” thanthe others — it uses T/R sequences of
only 15 seconds.
The program also supports three “fast”
modes — MSK144, JT9 (fast), andISCAT — with selectable T/Rsequence lengths of 5, 10, 15, or 30
seconds. The fast modes send information much more rapidly, repeating eachmessage many times during asequence. These modes are optimized
for meteor scatter, aircraft scatter, andother propagation types that yield shortbursts of usable signal strength. Finally,
WSJT-X supports a quasi-beacon mode
known as WSPR2 (for “Weak Signal
Propagation Reporter”), used for probing worldwide propagation conditions,and Echo mode for measuring reflections of your own signals from theMoon.
Except for ISCAT, all protocols in
WSJT-X include a strong form of forward error correction (FEC). This
mathematically sophisticated methodof encoding information ensures thatwith very high probability, messages
displayed by the decoding software
will be exactly those that were originally encoded. Among many otherobvious advantages, strong FEC
means that in nearly all circumstances,received call signs, grid locators, signal
reports, and other information are highly reliable.
This article is not a “how-to”
guide for using WSJT-X; that
purpose is best served by anextensive WSJT-X User
Guide 3 and an active anduser-friendly online support
forum.4 Instead, in Part 1 ofthis two-part article, we provide highlights illustrating
the sort of things that can bedone with WSJT-X, and webriefly outline the stationequipment required. In Part
2, “Codes, Modes, andCooperative Software Devel2   October 2017

opment,” we explain how the various
protocols work. We also offer someinsight into how this all-volunteer software project has created an extremely
capable, open-source, fun-to-use software package that is freely available5
to all radio amateurs — including its
internal source code.6 We invite otherswith programming, documentation,
testing, and related skills and interests
to consider joining and participating inour ongoing development project.
Open sharing of our protocol specifications and source code has had thedesirable and beneficial side effect of
encouraging other programmers to create offshoot open-source programs,
such as JT65-HF, JTDX, and MSHV,
which typically implement and support
a small and targeted subset of the
WSJT-X capabilities. At the time ofthis writing, we estimate there areroughly 5,000 users of WSJT-X active
in a typical week, around the world.
Almost as many more are using the
WSJT-X modes and their encoding anddecoding algorithms in one of the offshoot programs mentioned. This stateof affairs is a fine example of goodham-spirit cooperation in an age whenstate-of-the-art communication engineering usually involves software aswell as hardware.

What WSJT-X Can Do
DXing with Weak Signals
The oldest of our slow modes, JT65,
was designed for Earth-Moon-Earth(EME) communication7 and is widelyused for that purpose today. However,even greater usage of JT65 (and thenewer modes, JT9 and FT8) can befound in spectral slices only a few
kilohertz wide on bands from 160
through 6 meters. An example of the
WSJT-X waterfall spectrogram for one
such slice is shown in Figure 1,
recorded on the 20-meter band about
2 years ago. WSJT-X decoded 13
JT65 signals in this arbitrarily chosen
1-minute time segment. All but threeof these signals overlap in frequency
with one or more others, but nevertheless they are decodable without errors.
Ten JT9 signals appear at the right sideof the spectrogram, above 2,500 Hz,
and they are also decoded without
errors. Evidently, at least 23 error-freecontacts are taking place simultaneously in about 3.5 kHz of spectrum.
More recently, we have sometimes
seen twice this number of decodable
JT65 and JT9 signals in a single minute, in one 4 kHz slice.

JT65, JT9, and FT8 are the mostwidely used WSJT-X modes, and probably the most popular machine-generated modes of any kind in AmateurRadio today. Thousands ofcontacts are made with
Table 1them every day, on amaConventional Dial Frequencies forteur bands from MF
FT8, JT65, JT9, and WSPR on the HF Bands
through microwaves.
Band (m)Frequencies (MHz)Many amateurs have comFT8
JT65
JT9
WSPR
pleted WAC, WAS,
160
1.840
1.838
1.839
1.8366
DXCC, and other awards
80
3.573
3.570
3.572
3.5686*
using these modes, often
40
7.074
7.076
7.078
7.0386
with low-power and sim30
10.13610.13810.14010.1387
ple antennas. Signals at
20
14.07414.07614.07814.0956
least 10 dB below the17
18.10018.10218.10418.1046threshold of audibility are15
21.07421.07621.07821.0946
generally decodable in all
12
24.91524.91724.91924.9246
the 1-minute WSJT-X slow
10
28.07428.07628.07828.1246
modes, and FT8 is only a650.31350.310†50.31250.293few decibels behind. For*Pending change from 3.5926, †Pending change from 50.276
most humans, the audible

ARRL, the national association for Amateur Radio®

www.arrl.org  threshold for such signals (and for
Morse-coded CW) occurs at signal-tonoise ratios around –15 dB, measured
in a reference bandwidth of 2,500 Hz.
By informal convention, subband
slices for FT8, JT65, and JT9 currently
begin at the upper-sideband dial frequencies listed in Table 1. If you’recurious and have not previously used
one of these modes, try downloading
WSJT-X from the WSJT home page.5
Install the program on your shackcomputer or laptop, set your transceiver to upper-sideband mode at
7.076 or 14.076 MHz, turn up the
speaker audio, and start monitoring in
JT65 mode using the computer microphone for audio input to WSJT-X. Be
sure that your computer clock is set tothe correct time, within a second or so.
On an open band, you should hear themusical tones of JT65 signals, startingat the top of each UTC minute, and see
the signals on the waterfall display.
Near the end of each minute, decoded
messages should appear in the WSJT-X
Band Activity window. The messages
will probably look something likethese examples:CQ UX1LW KN89
W3DJ LU2BN 73
PY4SM CP6UA -15
PY1ME PY6JB R-07
K7PWL K1NOX RRR

Two-way contacts in any of the WSJTX modes usually start in the traditionalway, with someone answering anotheroperator’s CQ. Messages exchanged ina minimal contact then proceedroughly as follows:
1. CQ KA2ABC FN20
2. KA2ABC G8XYZ IO92
3. G8XYZ KA2ABC -17
4. KA2ABC G8XYZ R-21
5. G8XYZ KA2ABC RRR
6. KA2ABC G8XYZ 73

Standard messages in WSJT-X usuallyconsist of two call signs followed by agrid locator, signal report, acknowledgment, or 73; CQ or QRZ may be

Figure 2 — PSK Reporter world map showing open propagation paths for spotted JT65 andJT9 signals over a 1-hour interval around 1630 UTC on February 13, 2017. Different colors indicate signals on different bands. Magenta is 80 meters, blue is 40 meters, yellow is 20 meters,
and brown is 15 meters.

substituted for the first call sign. Signal
reports are expressed as signal-to-noise
ratios measured in a 2.5 kHz bandwidth. You can also send any free-text

beacon” networks that show where asignal is being copied and what worldwide propagation paths are open at thepresent time. The central hub of one of
the most successful suchnetworks, PSK Reporter, 8These modes are not designed for
was developed by Philiplong conversations or “ragchewing.” Gladstone, N1DQ. WSJT-X
optionally sends reception
reports to its website, where
message containing letters, numbers,
you will find a world map showing
basic punctuation, and spaces up to aopen propagation paths color-coded by
maximum of 13 characters — one
frequency band. PSK Reporter canmight say, roughly equivalent to aalso display reported call signs, locators, and other information, and can“deci-Tweet.” We already mentioned
filter the displayed map by band, callthat these weak-signal modes are notsign, operating mode, and other critedesigned for ragchewing! Consult theria. In the background, it carries out
WSJT-X User Guide for additional
other tasks, such as statistical analysis
details and limitations concerning
message structure — for example, how and limited archival storage of data.
More than a million reception reports
to accommodate compound call signs
are currently received by PSK
like PJ7/KA2ABC.
Reporter every day, and about 98%
Monitor Propagation Conditions
are for JT65, FT8, and JT9 signals.
About a decade ago, we realized that
Figure 2 is an example screenshot
because call signs and locators areshowing open worldwide signal paths
decoded very reliably in FECon the HF bands at mid-morning in theenhanced modes like JT65, andcentral United States.
because the computers in most ham
shacks are connected to the internet, it WSPR mode provides another popular
tool for probing propagation condishould be possible to create “reverse
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Figure 3 — Screenshot showing small portions of
the WSJT-X Fast Graph window and main window
when running in MSK144 mode. The bright vertical
stripe at time t = 1.1 s is a moderate-strength meteor“ping” lasting about 70 milliseconds. The decoded
message shows that K9AN is calling K1JT.

tions. In this case, the relevant signals
are not part of two-way conversations
between amateurs, but rather one-way,
low-power quasi-beacon transmissions
received at another location andreported automatically to the WSPRnet
website.9 All WSPR-mode capabilities, including coordinated bandhopping, have now been incorporated
in WSJT-X (see Note 2 and the WSJT-X
User Guide for further details).
Meteor Scatter
About a year ago, we started experimenting with MSK144, a new protocol
designed explicitly for amateur meteor
scatter (MS) communication. MSK144
has rapidly become the dominant modefor MS contacts, worldwide. On the

6-meter band, with 100 W and amodest antenna — say a three- or
four-element Yagi, a two-element
Moxon, or even a dipole or omnidirectional halo up 20 feet or
more — you can make contacts
out to beyond 1,000 miles at
essentially any time. More power
and a better antenna will make formore (and quicker) contacts. On 2
meters, a good starter station for
MS is 100 W and a ten-element
Yagi. Figure 3 shows what ashort, moderate-strength meteorinduced “ping” looks like on the
WSJT-X horizontally scrolling
spectrogram.

As an example of what can be done,
we note that many hundreds of
MSK144 contacts were made during
the January 2017 VHF Sweepstakes.
Most of these contacts yielded additional contest multipliers for the participating stations. Figure 4 provides a
pictorial summary of 50 MHz
MSK144 activity on a Saturday morning in February 2017, taken from thePSK Reporter website. February is
generally a slow month for meteor
scatter activity, because it includes nomajor and few minor meteor shower
events. Sporadic meteors are present atnearly all times, and are sufficient formaking MSK144 contacts.

Figure 4 — A map from PSK Reporter showing activity with MSK144 on a Saturday
morning (Eastern US) in February.

4   October 2017

ARRL, the national association for Amateur Radio®

MSK144 is a “fast” mode with selectable sequence lengths. In North America and Europe, T/R sequences of
15 seconds have become the default
standard. The MSK144 decoder operates in real time, so you see decoded
messages immediately after each
decodable ping. Pings as short as
0.1 seconds are usually decodable if
the signal-to-noise ratio is 0 dB orhigher. Weaker pings lasting 1⁄2 secondor longer can be decoded at signal-tonoise ratios as low as –8 dB. Suchpings are barely audible, if at all.
The MSK144 protocol uses strong
FEC and the same structured messages
as the WSJT-X slow modes. The resulting nearly error-free decoding makes it
possible to use automatic message
sequencing. The program can keep
track of where you are in the standard
contact sequence and automaticallyselect the appropriate message to send
for each transmission.
Meteors are several times more frequent around sunrise, so MS contacts
are quicker in the morning than in theafternoon or evening. The duration of“pings” is inversely proportional to thesquare of frequency, so usable pings at
144 MHz and higher bands are both
shorter and less frequent than those at
50 MHz. Nevertheless, MS contacts
are still fairly easy at 144 MHz using
MSK144, and with persistence they
are possible at 222 and 432 MHz.
Moonbounce with
Modest Equipment
The extremely high sensitivity of theslow modes in WSJT‑X is particularly
important on VHF and higher bands,
especially on such difficult links as the
Earth-Moon-Earth path. Simply stated,
EME communication is at least “10 dB
easier” with these modes than with
CW or other traditional modes. The
default mode for digital EME on the
VHF and UHF bands is JT65. The
new mode QRA64 is gaining popularity on these bands as well, and bothwww.arrl.org  

Most of these contacts are with stations in Europe, close to his antipodes.

Figure 6 — The portable EMEcapable 10 GHz station of
VK7MO, set up at roadside in
the Australian Outback. [RexMoncur, VK7MO, photo]
Figure 5 — The 12-element Yagi antenna used by
DL1VPL to complete DXCC on 144 MHz. [Thomas
Hartig, DL1VPL, photo]JT4 and QRA64 are used for EME on
the microwave bands 2.3 GHz andhigher.
We know of at least three hams withmodest single-Yagi stations who haveworked 100 or more different countries on the 2-meter band. Of course,
most of the necessary contacts weremade over the EME path. Figure 5
shows the 12-element Yagi used byThomas Hartig, DL1VPL, to complete

his 2-meter DXCC award. Anotherexample of “doing the most with theleast” is the 10 GHz portable EME
setup of Rex Moncur, VK7MO, shownin Figure 6. Rex’s setup includes a
10 GHz transverter, a 50 W solid-state
power amplifier, and a 2.5-foot(75-centimeter) dish mounted on a collapsible tripod. He has made hundredsof EME contacts with this equipmentusing the JT4 and QRA64 modes.

Rig Control and
Frequency Calibration
WSJT-X provides for optional computer-aided transceiver (CAT) controlof nearly all modern radios. The necessary communication between radio
and computer takes place over a USB
or serial port. Relevant rig-control features include T/R switching, frequency
and mode setting, and options such as
split operation and automatic Doppler
compensation for the EME path. The
CAT-control portion of our software
makes use of an open-source libraryknown as Hamlib,10 to which many
active hams have contributed.
Many capabilities of WSJT-X dependon the software’s use of signal-detection bandwidths of no more than a few
hertz. This puts a special premium onfrequency accuracy and stability.
WSJT-X provides tools that enableaccurate frequency calibration of yourradio, as well as precise frequency
measurement of on-the-air signals. The
calibration procedure works by automatically cycling through a series ofpreset frequencies of carrier-based signals at reliably known frequencies. We
find that major-city AM broadcast stations can serve as frequency calibrators

Figure 7 — The WSJT-X frequency calibration procedure cycles
through a list of AM signals with reliably known frequencies, spending 30 seconds with the radio dial set 1,500 Hz below each frequency. Station call signs and frequencies in megahertz have been
added to the figure.

Figure 8 — Upper portion of the Settings → Frequencies tab, showing the entry fields for frequency calibration of your radio.

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October 2017   5

Figure 9 — Dependence of dial error on frequency, measured for a
Yaesu FT-2000. Parameters of the best-fit calibration line are indicatedin the figure.

Figure 10 — Lunar echo of the K1JT signal on 144 MHz measured
using Echo mode in WSJT-X.

at the low frequency end of the spectrum, and in North America, we use
the standard time-and-frequency
broadcasts of WWV and CHU atconstant is 24.6/20 = 1.23 parts per
million. This number may be enteredon the Frequencies tab of the Settings
window (see Figure 8). A more precise
calibration can be effectedby fitting the intercept andMany amateurs have completed
slope of a straight line to
WAC, WAS, DXCC, and otherthe whole sequence of caliawards using these modes, often
bration measurements, aswith low power and simple antennas. shown for these measurements in Figure 9. Softwaretools for completing thishigher frequencies. Similar shortwave
task are included with the WSJT-X
signals are available in other parts of
installation, and detailed instructions
the world.11 During the calibration
for their use are available online.12
procedure, the radio’s USB dial freUsing these tools and no specialized
quency is offset 1,500 Hz below eachhardware beyond your CAT-interfaced
frequency in the list. As shown in Fig- radio, you can calibrate the radio toure 7, detected signal carriers therefore better than 1 Hz and compete very
appear at about 1,500 Hz in the WSJT- effectively in the periodic ARRL FreX waterfall.
quency Measuring Tests.
With modern synthesized radios, small
measured offsets from 1,500 Hz will
exhibit a straight-line dependence on
frequency. You can approximate thecalibration of your radio by simply
dividing the measured frequency offset(in Hz) at the highest reliable frequency by the nominal frequency itself(in MHz). For example, the 20 MHz
measurement for WWV shown in Figure 7 produced a measured tone offset
of 24.6 Hz. The resulting calibration
6   October 2017

Aircraft Scatter
The ISCAT mode is especially effective for microwave contacts using signals reflected from high-flying aircraft.
ISCAT copes well with the rapidchanges in Doppler shift and shortbursts of signal lasting a second or so.
VK3HZ, using a 60-centimer dish and
7 W at 10 GHz and working VK7MO
as a rover, has increased his 10 GHz
grid locator total to over 80 using
mainly this mode of propagation.

ARRL, the national association for Amateur Radio®

Their longest contacts are over
900 kilometers (560 miles).
Echo Mode
Echo mode allows you to make sensitive measurements of your own signal
echoes from the Moon, even when
they are too weak to be heard. In thismode, WSJT-X transmits a 1,500 Hz
fixed tone for 2.3 seconds, waits about
0.2 seconds for the leading edge of a
return echo from the Moon, records
the received signal for 2.3 seconds,
and then analyzes, averages, and displays the result. The whole cycle isrepeated every 6 seconds, and the program calculates and compensates automatically for continually changing
Doppler shifts. As shown in thescreenshot in Figure 10, return echoes
should appear at frequency offset 0 Hz,
the center of the Echo Graph window.
Station Requirements
and Summary
Station requirements for using WSJT-X
are essentially the same as those forother computer-assisted modes. You
will need an SSB transceiver, anantenna, a computer preferably built in
the past 6 or 8 years, and a monitor
with at least 1,024 × 768 pixels resolution. Computer-to-radio interfacing
usually requires a serial port or equiva-

www.arrl.org  lent USB device for T/R switching;using your rig’s VOX is also possible.
T/R switching uses CAT commands ifyour rig supports it, or serial port signals on either a CAT connection or aseparate port. Output from the computer’s sound card (or equivalent) shouldbe patched to the radio’s Data input, orMicrophone if no Data input is available. Received audio goes to the computer’s Line input or a combined Line
input and Microphone connector. Auxiliary devices that handle these connections are widely available as
homebrew projects or commercial
products. Some recent radios haveeverything built in so that only a single
USB cable is needed between computer and radio. You will also need ameans for synchronizing the computer
clock to UTC within ±1 second. Further details and setup instructions canbe found in the WSJT-X User Guide(see Note 3). We recommend particularly the Basic Operating Tutorial andthe downloadable sample files for eachmode. You can get answers to specificsetup questions from the online support forum (see Note 4).

yahoogroups.com.

5physics.princeton.edu/pulsar/k1jt

6Source code for WSJT-X and its sister pro-grams is publicly available at https://sourceforge.net/projects/wsjt.
7Joe Taylor, K1JT, “The JT65 Communications
Protocol,” QEX, Sep./Oct., 2005, p. 3.
8Philip Gladstone, N1DQ, https://pskreporter.

Joe Taylor was first licensed as KN2ITP in
1954, and has since held call signs K2ITP,WA1LXQ, W1HFV, VK2BJX, and K1JT. He
was Professor of Astronomy at the Universityof Massachusetts from 1969 to 1981, andsince then Professor of Physics at Princeton
University, serving there also as Dean of theFaculty for 6 years. He was awarded theNobel Prize in Physics in 1993 for discoveryof the first orbiting pulsar, leading to observations that established the existence of gravitational waves. After retirement, he has been
busy developing and enhancing digital protocols for weak-signal communication by Amateur Radio, including JT65 and WSPR. He
chases DX from 160 meters through themicrowave bands. You can reach Joe at
joe@princeton.edu.
Steve Franke, K9AN, holds an Amateur Extra
class license. He was first licensed in 1971
and has previously held call signs WN9IIQ
and WB9IIQ. An early and abiding fascination
with radio science led to his current positionas Professor of Electrical and Computer
Engineering at the University of Illinois in
Urbana-Champaign. Steve is a member of
ARRL and a Fellow of the IEEE. You canreach Steve at s.j.franke@icloud.com.
Bill Somerville, G4WJS, read Chemistry at
the University of Bristol in the UK, graduating
in 1978 with a Bachelor of Science degree.
Since graduating, he has worked in computer

info/pskmap

9wsprnet.org/drupal/node

10https://sourceforge.net/p/hamlib/wiki/

Hamlib11www.smeter.net/stations/hf-time-frequency.

php

12https://physics.princeton.edu/pulsar/k1jt/

FMT_User.pdf

software and hardware in a variety of industries including defense, software vendors,
and financial services, more recently as afreelance consultant providing systems programming and related services to mid- tolarge-size software tool vendors. Bill has
been an active radio amateur since 1981,
holding the calls G6IJU and G4WJS. He
enjoys HF and VHF bands, contest operating,and DX chasing using CW, phone, and data
modes. He is a keen walker and swimmer. Bill
participates in open-source software projects
for Amateur Radio, with WSJT-X being thelargest contribution. Bill is happy to provide
input, drawing on his extensive software engineering experience, to help those with otherimportant domain skills provide robust, professional standard, software-based AmateurRadio communication tools. You can reachBill at bill.8@classdesign.com.

For updates to this article,
see the QST Feedback page at
www.arrl.org/feedback.

Space requirements have limited us toa list of WSJT-X capabilities that is far
from complete. Nevertheless, we hopeto have given you a good feeling for
New Products
the program’s wide range of capabiliSmartSDR for iOS from FlexRadio Systems andties. In Part 2 of this two-part article,
Marcus Roskosch, DL8MRE
we outline some fundamentals of com- SmartSDR for iOS offers FLEX-6300, FLEX-6500 and FLEX-6700 owners themunication theory, describe the distin- ability to operate from home or remotely through their Apple mobile device.
guishing features of each WSJT-X
SmartSDR for iOS provides many of the same features as SmartSDR for Windows
protocol, and explain how the prowithout the necessity of using a PC. You can operate in any mode, and the application
gram’s seemingly all-but-magic tricks
can run along with programs on your PC such as N1MM Logger+ or CW Skimmer.
work. We then give a brief overview of SmartSDR for iOS offers options such as a visual band plan and DX Cluster
integration. Band limits, modes and DX-Cluster spots will be displayed right inside
the project’s cooperative software
the panadapter.
development tools and procedures.
Notes

1Joe Taylor, K1JT, “WSJT: New Software for VHF

Meteor-Scatter Communication,” QST, Dec.
2001, pp. 36-41.

2Joe Taylor, K1JT, and Bruce Walker, W1BW,“WSPRing Around the World,” QST, Nov. 2010,
pp. 30-32.
3www.physics.princeton.edu/pulsar/K1JT/
wsjtx-doc/wsjtx-main-1.7.1-devel.html
4groups.yahoo.com/neo/groups/wsjtgroup/
info; e-mail address wsjtgroup@

To run SmartSDR for iOS the operator will need a FLEX-6000 series radio and an
Apple device such as an iPad, iPhone or iPod Touch running iOS 9.0 or greater. A
newer iPad (3, Air 1 or newer) or iPhone (5s or better) is recommended. To run thisapp at your home, only a regular WiFi connection is needed. You can immediately
start using the app. To run the app and to operate your FLEX-6000 series radio fromanother location, you need to have a Virtual Private Network (VPN) connection to
your home network. SmartSDR for iOS is available from the App Store for $49.
Optional features such as the DX Cluster and Band Plan are priced at $4.99. For more
information, visit www.flexradio.com.
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October 2017   7