Whispering on WARC

Of late I have been focusing a bit on working Europe on the WARC bands to close the gap on Worked All Europe first class award (WAE I).  I have also boosted the numbers slightly on 40m. JT65 has made it possible to work pretty reliably into EU most days and evenings on 30 or 17. While experimenting with WSJT-X 1.1 this weekend, I finally saw Cliff VK2CCJ working KH6OO on JT9 in the 12m band.  We eventually connected with this exciting new mode.

The Summer Wraps Up

Snow today for the first time since May 23. It was a short summer.  Leaves and ground cover are in full blaze of yellow, orange, and red.  The contrast of snow on dark spruce and low-hanging clouds ringing the hills made for a dramatic landscape.  Alas, antenna season wanes quickly.  A 40 meter vertical project hangs in the balance.

Living for much of the summer under threat of wildfires, the station has been largely pieced back together.  A full multi-2 is nearly 100% functional.

The rig has been on quite a bit lately monitoring JT-65A on the low bands.  I have been using JT65-HF for ages, but recently found WSJT-X 1.1 works faster and decodes more effectively on my slow XP PC.

John AL7ID, who lives just a few miles east of KL2R, put up a full-size 160m loop around his property.  Comparisons on the various bands has been interesting.  The 30m band has outstanding worldwide coverage much of the day now, and 40 has had some strong nights for DX.  A61BK was even heard here at midday on a dipole, which was totally anomalous.  160 yields the Lower 48 as sunrise moves across the US, and 80 has been marginal most evenings.

Nearly two weeks ago I was in Anchorage re-building KL7SB's shack with a complete Elecraft K3 line and Microham MK2R+ SO2R box.  I will do it again in a few days.  Given the uncertainty of the 40m project at home, I might as well do something useful.

Weak Signal Redux with JT65A

While I like to operate a fair amount on PSK31 during non-contest time, that mode simply is not robust enough to cope with the flutter and Doppler smearing on the trans-polar paths.  To be fair, the popularity of PSK31 and its performance on a light band make it a valuable asset in the mode arsenal.  However, phase-shift keying detection requires a relatively pristine and stable carrier.  Also, the lack of forward error correction in the data stream makes it completely vulnerable to corruption caused by the peculiarities of a turbulent ionosphere.

Various other weak signal modes on HF have captured my interest for a while, as you can see by reading earlier posts on playing with Olivia during a solar storm and impressive results on QRP via the Weak Signal Propagation Reporter Network.  Modes based on multi-tone frequency-shift keying are inherently better suited than PSK for rough skywave conditions.  Detection is easier, because the demodulator does not have to lock to an unsteady carrier.  Also, if the data stream carries some redundancy and/or error-detection or error-correction coding, the impact of a lost tone here and there due to selective fading can be minimized.

Over a decade ago, Joe Taylor K1JT began to develop some rather robust modes for weak signal communications at VHF to bring exotic propagation modes like moonbounce and meteorscatter more down to earth for hams unable to erect giant arrays and to run legal limit power amplifiers.  The project evolved into "Weak Signal Communicatons, by K1JT", or WSJT for short.  The protocols now in use include FSK441 for meteorscatter and JT65, which has proven very popular for V/UHF moonbounce and is increasingly used by weak-signal enthusiasts for HF skywave propagation.  JT65 has a number of sub-modes, but you will find JT65A in common use on the HF bands.  If you have a soundcard interface for your radio and can keep the PC clock fairly well synchronized, you have all the fixin's for a JT65A operation once you add some software.

Several weeks ago I downloaded the WSJT 9.0 package, which is available for Windows and Linux.  I must admit to have been a bit overwhelmed by reading through the user's guide, but eventually things started to make some sense.  Getting everything set up and ready to use takes some deliberation, and it helps to have an experienced Elmer to guide you through getting on JT65A.  (The Alaska-Yukon Weak Signal Group is a great resource for us northern hams.)  Those a bit impatient who just want to cut to the chase with a single mode can download JT65-HF written by Joe Large W6CQZ.  The software runs on Windows only.  The interface is  intuitive, and soon you can be pointing and clicking your way to DXCC.

Make no mistake.  JT65A is not a ragchewing mode.  Each transmission and decoding cycle takes about one minute, and messages are limited to 13 characters.  Nevertheless, it is very effective getting basic information exchanged across an otherwise-impossible channel, even more effective than CW when the signal-to-noise ratio dips to the -10 to -20 dB range.  Case in point:  Last night on 40M, I monitored an exchange between ZS (South Africa) and FR (Reunion Island) in the SW corner of the Indian Ocean.  I couldn't hear a thing, and I could barely make out the tones on the waterfall display.  

JT65A is powerful stuff!  Many operators use 10-25W into simple wires or vertical antennas for worldwide contacts.  These are during conditions in which your grand pappy would have had sense enough to go fishing instead.