Digital%20HF:%20what%20are%20you%20waiting%20for?

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Join The Fun!

• Digital HF what are you waiting for?
• A presentation for the Gloucester County ARC,
  NJby Jim Wright (N2GXJ) and Ken Newman (N2CQ)

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Why add digital modes?

• Be honest
• Tired of your old radio?
• Too much static in the headset?
• Frustrated with band conditions?
• Tired of the same old operators?
• Want to meet some new hams?
• Want to enjoy more DX?

Then maybe the HF digital modes are for you!
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HF digital modes

• To quote long time ham, NB6ZThe distinguishing
  features of live HF digital operation today are
  the use of lower power, compact or indoor
  antennas, and courteous operating technique. This
  reverses the trend of several years ago
• Unexpected operating benefits
• When operating radio in digital mode, theres no
  microphone, no noisy speakers, no headset
  required!
• Break free of the shack! With a laptop, can enjoy
  quiet time with your significant other, sitting
  together on the couch (pretending) to watch your
  (their) favorite (reality) TV show, while still
  chasing DX! ( Just saying Not that anyone
  would do this... Would they?)

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Band conditions

• Conditions are terrible. The bands must be
  closed.
• Not so fast!
• It used to be that you had to hear em to work
  em
• Not so with some of the modern digital modes!To
  put it in perspective, a 2002 study found
  majority of CW ops could copy at an S/N ratio of
  0db, but less than 4 could copy down to -7db.
  Contrast that with digital mode Olivia which
  can be decoded when it is 10-14 db below the
  noise floor (noise is 3x stronger than the
  signal!) And digital mode JT65HF, with QSOs
  possible to -20db! ref The Weak-Signal
  Capability of the Human Ear, Ray Soifer, W2RS,
  Proceedings of the Central States VHF Society
  Conference, 2002
• Low sunspots, spectrum crowding, fading, impulse
  noise, static crashes, QRM, QRN, QSB, you name
  it
• Modern digital modes are popular because they can
  work well, even under less than ideal conditions!

Bands seem dead? Try HF digital modes instead!
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Enjoy more DX!

• Its hopeless. Ill never get DXCC.
• Wrong! Were lucky living on east coast USA!
• You just need to try HF digital modes, theyre DX
  friendly! (See the 4 hour reception map on the
  title page of this presentation)
• Its not uncommon to log more than a dozen
  countries in a single hour with one mode (PSK31)
  on one frequency (14.070 Mhz).
• Worked All States (WAS) and mixed mode DX Century
  Club (DXCC) awards in less than a year with under
  50W and only a dipole antenna up in the attic?
  Yes, you can! (e.g. n2gxj)
• If youre an SSB and/or CW op, for fun, why not
  consider adding digital modes to your existing DX
  options?

Digital modes are DX friendly!
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Meet new hams!

• Theres a growing community of new digital users
  out thereall over the globe, on all bands, at
  all hours of the day!
• Digital is the fastest growing area of our
  growing ham radio hobby! ref2

ref1 http//pskreporter.info/pskmap.html
4/21/2012 ref2 Ham Radio for Dummies,
W.Silver, WileySons pub
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Enjoy more DX!

• East coast stations regularly catch digital DX

ref http//pskreporter.info/cgi-bin/pskstats.pl
4/17/2012
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Enjoy more DX!
ref http//pskreporter.info/cgi-bin/pskstats.pl
4/17/2012

• Maybe add digital modes to your existing DX
  capabilities?

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A typical Saturday afternoon

• How many digital QSO can you count in this 3khz
  of audio bandwidth?

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Panoramic simultaneous decode!

• That looks fun! Ready to give it a try?

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Adding digital capabilities

• Goals
• Upgrade, not replace, existing HF radio ()
• Preserve your existing CW/SSB capabilities!
• Add a whole new world of HF digital
  possibilities!
• How to? The options
• If your radio is an SDR, just add digital
  software ?
• Else, connect audio jacks/ptt on your radio via
  an adapter to ports on your PC, then add digital
  software to your PC
• Via build-it-yourself interface, or
• Via buy-it-yourself interface

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Build or Buy interface

• Basic elements of either approach
• (RX) Audio from radio into the PC
• (TX) Audio from PC to the radio
• (TX KEY) PTT, or VOX, for transmit

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Build-it-yourself
ref http//www.qsl.net/wm2u/interface.html

• For the saver, DIY enthusiast
• For SWL, no circuit needed. Just let computers
  built-in mic listen to the radio
• For clean RX/TX, use cables and the PCs sound
  card for A/D, D/A conversion
• Simple connection shown above, with VOX enabled
  on radio for TX, may be all you need
• If ground loop issues, use audio transformers, as
  shown on right

ref http//www.hamradio.cc/projects/psk31/PSK31.
pdf
If you are thinking of BIY, a recommended
reference http//www.qsl.net/wm2u/interface.htm
l
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Buy it Yourself
Ref Pictured units and trademarks are property
of their owners SignaLink
(Tigertronics), RIGBlaster (West Mountain Radio),
MFJ (MFJ)

• Easy install
• Vendor often can supply cables specific for your
  radio model
• Interface simplicity
• USB between Box and your PC (most PCs dont have
  RS232 anymore)
• Interface box contains its own soundcard
• Soundcard in PC can still be used for PC sound

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Digital mode software

• Hundreds of choices
• Some that may have been good in 1999, or even
  2007, just cant compare to the most popular
  choices in use today
• Some features to consider
• Continued support/upgrades
• Compatibile with your PCs OS
• If it has the modes you want
• Ease of integration with contesting/logging
  program(s)
• Interfaces with online service(s)
• Callsign lookup
• Electronic QSL services
• Spotting networks
• Reverse beacon networks
• Cost

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Multimode or specialty?

• Start with a multimode software package
• Lets you operate many popular modes without
  switching programs
• Learn once, use for many modes, higher enjoyment
• Tend to be more modern, more features, more fun
• Get familiar with one, then can compare with
  others,at your leisure
• Later can look into specialty programs, e.g.
• Weak signal beacons/reception reporting (e.g.
  WSPR),
• Weak signal QSOs (e.g. JT65HF),
• Digital slow scan TV (e.g. EasyPal),
• Digital modes on smartphones (see cover story of
  May 2012 QST magazine)

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Top Picks (imo)(alphabetical)

• Fldigi (http//www.w1hkj.com)
• Available for Linux, OSX, and Windows. Popular
  for narrowband messaging, emergency comms use.
  Free.
• HRD/DM780 (http//www.hrdsoftwarellc.com)
• Package includes integrated rig control,
  decoders, logger, and much more. Windows. Pay
  after June 2012.
• MixW (http//mixw.net)
• Windows. Favored by many digital contesters. Pay.
• Multipsk (http//f6cte.free.fr/index_anglais.htm)
• Some consider this the swiss army knife of
  digital software packages. Register (pay) version
  more full featured.
• older (Digipan, Hamscope) try a few, see what
  works for you!

Ref with links to these, and more
http//www.westmountainradio.com/content.php?page
links
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Topics for future presentations

• Many digital software packages integrate with
  electronic logging systems (like LoTW, eQSL,
  HRDLOG.net), and online services (such as
  callsign lookup (e.g. qrz.com), DX clusters, and
  reverse beacon networks (above qsos logged in
  last hour, hrdlog.net))
• Each of these are involved enough to be candidate
  topics for future discussion!

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Digimodes

• These are the ones to start with
• Radio Teletype (RTTY) Frequency Shift Keying
• PSK31 Phase Shift Keying
• After those, you might consider adding some of
  these modes to your digital DX repertoire
• MFSK - if one or two tones are good, why not
  more?
• JT65a - just for DX qso credit. No conversations
  at all.
• Olivia - conversational, even for very faint
  signals
• Hellschreiber let your eyes do the fax
  processing
• SSTV - sending regular and high def pictures over
  HF
• How to recognize these modes, and where to look
  for them on the dial? (well cover that next!)

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When getting started

• Tip 1 Digital modes are typically 100 duty
  cycle, often with long duration transmissions.
  Care should be taken to avoid overheating and
  damaging your radio finals.
• Keep power levels low
• consider temperature monitoring, additional
  cooling, fans
• Tip 2 Overdriven audio is most common cause of
  band splatter.Is easy to avoid being the guy
  with the ghosting shown above.
• Turn off SSB compressor
• Reduce audio drive levels to below AGC threshold

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RTTY

• One of the oldest modes, in use since WW II
• Popular for DX and world-wide radio contests
• Continuous transmission using FSK (or AFSK)
  between two tones
• Common 28.080-28.100, 21.080-21.100,
  14.080-14.099, 7.080-7.100 Mhz
• Typical setting 45.45 baud, 170Hz shift between
  tones
• Support for other bauds/shifts common, as is
  reverse to allow use with USB or LSB radio
  setting (EU stations tend to use USB)
• Limited character set (e.g. UPPER CASE ONLY)

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RTTY QSO

• RTTY QSOs tend to be brief, particularly for busy
  DX stations, and for contests where only calls
  and signal reports need to be exchanged (no
  names, serial numbers, nor locations
• Simulated brief QSO example
• gt CQ CQ CQ DE N2GXJ N2GXJ (n2gxj calling cq)
• lt W2MMD W2MMD (w2mmd answers)
• gt W2MMD 599 599 W2MMD (n2gxj acknowledges w2mmd,
  with sig report)
• lt N2GXJ 599 TU (w2mmd confirms report, and
  returns n2gxjs)
• gt 73 DE N2GXJ QRZ? (n2gxj confirms report, and
  asks for next station)
• Of course, RTTY is a keyboard typing mode, so you
  can ragchew for hours instead if you want
• and some do!

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Operating RTTY Split

• Rare DX and DXpeditions will often run RTTY
  split, where they TX on one frequency, and
  listen in range up/down 1-5 Khz
• e.g. CQ CQ 7O6T UP 1-2
• Tip use split capability of your decoding
  software, instead of your radios split
  capability when up is lt3 Khz
• See DX stations TX and how he is up answering
  on same waterfall
• Easy drag/drop your TX freq to most likely place
  to be answered next!

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PSK (31,63,125)

• Very popular!
• 31Hz bandwidth advantages QRP DX, less spectrum
  crowding
• Seems like you can always find some PSK tracks
  on air!
• Wheres the band open to? (Just check whos on
  the psk frequencies!)
• Common dial frequencies 50.290, 28.120, 24.920,
  21.070, 18.100, 14.070, 10.140, 7.040, 3.580,
  1.838 Mhz.
• PSK in different widths (31, 63, 125 Hz)PSK31 is
  better decode, but PSK63/125 faster for contests
• varicode, so lower case letters send faster (cq
  cq cq)

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PSK QSO

• PSK QSOs tend to be push-button English language
  macros, with certain fields filled in by the
  software.Simulated example
• gt CQ CQ CQ DE N2GXJ N2GXJ PLS K
• lt N2GXJ DE W2MMD W2MMD
• gt W2MMD DE N2GXJHello OM, UR RST 599 599QTH
  Sewell, New Jersey LOC FM29krName Jim
  JimClubs GCARC, EPC 15956, PODXS070 1424How
  Copy? BTU W2MMD de N2GXJ kn
• (and on-and-on, often with brag file
  about antenna, etc)
• Even with prevalent macro use, once basics are
  out of the way, its still possible to end up in
  30 minute typing ragchews, especially on lower
  bands

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Other modes MFSK16

• MFSK16 frequency shifts between 16 tones to
  improve signal detection in presence of random
  distortions, including multipath
• Look for signals near 14.078, 3.584 Mhz (ref
  bandplans.com)
• Not seen that often. Other digital modes based on
  frequency shifting between multiple tones are
  more common (including JT65a for HF, discussed
  next)

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Other modes JT65a

• Developed for moon-bounce, then adapted for HF,
  is a popular weak signal mode for DX (many
  signals shown in the 1.5 Khz audio trace above)
• 25 Watts is considered high power! Decodes to
  -20db S/N levels possible
• Common dial frequencies 28.076, 21.076, 18.102,
  14.076, 7.076 Mhz
• QSOs are SLOW. Stations alternate even/odd
  minutes with 46.8 second transmissions
• Coordinated time synchronization of PCs needed
  for reliable decodes

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JT65 QSO

• JT65A QSOs are very rigid and just convey the
  bare essentials callsigns, signal reports, and
  locations. (no chat mode)
• Simulated example
• odd gt CQ N2GXJ FM29 (n2gxj calling cq from
  Maidenhead grid square location FM29)
• evenlt N2GXJ JE1LET PM95 (je1let answers, giving
  his location)
• oddgt JE1LET N2GXJ -13 (n2gxj acknowledges
  je1let, returning signal report of -13Dbm)
• evenlt N2GXJ JE1LET R-12 (je1let confirms report,
  and returns n2gxjs report of -12Dbm)
• oddgt JE1LET N2GXJ RRR (n2gxj confirms receipt of
  his signal report, so je1let wont resend)
• evenlt N2GXJ JE1LET 73 (je1let says thanks, n2gxj
  can then do same, or call cq again)
• Thats just one qso in 6 minutes
• Often takes longer due to misses, and need to
  wait for next cycle to repeat

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• Push buttons for each step in JT65 QSO

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JT65a Decode

• Can be confusing. There is a 13 character free
  form available in place of final 73 message, but
  without callsign, need to look at Hz delta
  frequency to see who sent (e.g. _at_2037, 0130 was
  KE0YI). Better to use the stock 73 message (push
  button answer 4).

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OliviaThe Magical Mode

• Robust QRP-friendly keyboard conversational mode
  with excellent resiliency to fading and noise
• QSOs possible even when cant hear it, or see it
  on the waterfall!
• Multiple bandwidth/tone format choices available
• 500/16, 1000/32 most common, 250/8 shown in
  example above
• Tuning Voluntary channelization per
  band/format e.g. DIAL14074.65kHzUSB -
  AudioCenterMarker 750Hz - Format 500/16,
  (14075.4kHz(Center_Freq)) DIAL14106.50kHzUSB -
  AudioCenterMarker1000Hz - Format1000/32,
  (14107.5kHz(Center_Freq)) DIAL18102.65kHzUSB -
  AudioCenterMarker 750Hz - Format 500/16,
  (18103.4kHz(Center_Freq)) DIAL21086.50kHzUSB -
  AudioCenterMarker 750Hz Format 500/16,
  (21087.25kHz(Center_Freq)) DIAL21152.50kHzUSB
  - AudioCenterMarker1000Hz - Format1000/32,
  (21153.5kHz(Center_Freq)) DIAL28076.00kHzUSB -
  AudioCenterMarker 750Hz - Format 500/16 ,
  (28076.75kHz(Center_Freq)) (see
  http//hflink.com/olivia, http//bandplans.com/ind
  ex.php?nameOlivia)
• Expect a lag from signal on to decode start of
  4-6 seconds

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Hellschreiber (Feld-Hell)

• Fax-based teleprinter system, used by the Germans
  during WW II
• Translated as light writer, result is a dot
  matrix print
• Unique, in that it is visually-based decode mode
• Turns out human brain is very good at reading
  text in noise
• Look for signals below PSK range 14.063-14.069
  Mhz
• Dedicated enthusiasts love the mode, maybe you
  too?(ref http//sites.google.com/site/feldhellcl
  ub/Home/feld-hell-faq )

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SSTV/DSSTV

• Analog slow scan TV has been popular on HF for a
  long time. Send/receive GIF/JPG/BMP pictures via
  HF radio!
• Now high def Digital SSTV is getting lots of
  buzz, thanks to DRM (digital radio mondiale), and
  new software packages like EasyPal (refs
  http//www.g0hwc.com , http//www.qsl.net/kb4yz )
• Want to listen in? These digital signals are
  found in voice part of bands. Try SSTV near
  21.340, 14.230, 7.171 DSSTV near 21.337,
  14.233, 7.173 Mhz

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Recognizing signals by sight/sound

• Lets try a round of Decode that signal

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So whats holding you back?

• Join the thousands of hams using digital modes
  daily
• Enjoy DX with low power and an attic antenna
• Set aside all the static and shouting
• Play on the radio without disturbing the rest of
  the family
• Another way to help in emergency communication
  situations
• Extend your own horizons with new
  opportunitiesDigital contests, typing qsos,
  digi nets, awards
• Push your hobbys technology envelope
• Experiment with new modes, meet new people

Come on in, Join the Fun!
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Digital HFJoin The Fun!

• Thank you!